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R Colella

Publications and source records attributed to R Colella.

At least 19 recordsLinked to original sources
PubMed2006

Determination of the mechanism for resonant scattering in LaMnO3.

The resonant multiple Bragg x-ray diffraction is used to study the forbidden (104) reflection in LaMnO3. Using the interference between the three-beam scattering and resonant scattering we can determine the phase of the resonant scattering. This phase is shown to be consistent with a model in which the resonant scattering is caused by the influence of the Mn-O bond length distortion rather than directly by the orbital ordering on the Mn 4p band structure.

Journal Article↗
PubMed2005

[Cutaneous angiomyolipoma: a case report and literature review].

Angiomyolipoma is a lesion usually observed in the kidney of patients with tuberous sclerosis. Extrarenal sites are very unusual with sporadic cases in internal organ, soft tissue and skin (fifteen cases have been described in this site). Herein we describe an adding case located on the ear in 58-year-old man reviewing the pertinent literature. The main diagnostic differential criteria are also discussed.

Actins↗
PubMed2004

Molecular evidence of tumour cell removal from salvaged blood after irradiation and leucocyte depletion.

Intra-operative autologous blood recovery offers many advantages. However, blood salvage during cancer surgery is of limited use due to the potential presence of circulating tumour cells. It was the aim of this study to show that intra-operative salvage blood can be freed of cells and cellular DNA after leucoreduction by filtration and irradiation of washed blood. Known amounts of tissue culture derived from carcinoma, melanoma and osteosarcoma were added to whole blood bags. This mixture was then submitted to washing, leucoreduction and irradiation. Samples were studied stepwise in relation to the integrity and size of DNA by the polymerase chain reaction (PCR). After filtration and irradiation, PCR targeting the beta-globin gene (268 bp amplicon) was negative. Our results were corroborated by studying plasma samples added with tumoural cells. Using PCR methodology, we showed the absence of DNA from cells in experimentally contaminated blood and plasma bags after filtration and irradiation. This experimental study is an effort to ensure the safety of intra-operative autologous transfusion.

Blood Cells↗
PubMed2003

Decreased activity of cathepsins L + B and decreased invasive ability of PC3 prostate cancer cells.

Cancer metastasis involves multiple factors, one of which is the production and secretion of matrix degrading proteases by the cancer cells. Many metastasizing cancer cells secrete the lysosomal proteases, cathepsins L and B, which implicates them in the metastatic process. Cathepsins L and B are regulated by endogenous cysteine proteinase inhibitors (CPI) known as cystatins. An imbalance between cathepsin L and/or B and cystatin expression/activity may be a characteristic of the metastatic phenotype. To determine whether cystatins can attenuate the invasive ability of PC3 prostate cancer cells, cells were transfected with a cDNA coding for chicken cystatin. Expression of chicken cystatin mRNA was determined by PCR analysis. Total cysteine proteinase inhibitory activity, cathepsins L + B activity, and invasion through a Matrigel matrix were assessed. Stably transfected cells expressed the chicken cystatin mRNA and exhibited a significant decrease in secreted cathepsin L + B activity and a small increase in secreted cysteine proteinase inhibitor activity. The ability of cystatin transfected cells to invade the reconstituted basement membrane, Matrigel, was attenuated compared to nontransfected cells or cells transfected with vector alone. We have demonstrated that the cysteine proteinases cathepsins L and B participate in the invasive ability of the PC3 prostate cancer cell line, and we discuss here the potential of using cysteine proteinase inhibitors such as the cystatins as anti-metastatic agents.

Cathepsin B↗
PubMed2002

Absolute structure-factor measurements of an Al-Pd-Mn quasicrystal.

A number of X-ray reflections from an icosahedral quasicrystal Al-Pd-Mn have been measured with great accuracy on an absolute basis by making use of Bragg-case diffraction. Since the specimen had high crystal quality, the dynamical theory was used for analyzing the results and to extract structure factors from measured integrated intensities. Good agreement was found between theory and experiment for strong reflections. Anomalous transmission was found to be strong in the 'good' regions of the quasicrystalline specimen and it was measured on an absolute basis, but the small residual strains present in the specimen prevented an accurate comparison between theory and experiment. A detailed discussion is presented on the parameters that mostly affect anomalous transmission in relationship to the adopted structural model.

Journal Article↗
PubMed2000

GM1 enhances the association of neuron-specific MAP2 with actin in MAP2-transfected 3T3 cells.

The ganglioside GM1 is a glycosphingolipid which enhances process formation of several neuronal lines and potentiates some growth factor-mediated responses. Previously we have shown that 24 h exposure of Neuro 2a cells to GM1 mobilized the neuron-specific microtubule-associated protein, MAP2, away from microtubule-rich areas to areas of neurite sprouting where MAP2 was more closely associated with the subcortical actin network. To examine the role of GM1 in fostering the shift of the association of MAP2 from tubulin to actin, NIH 3T3 cells were co-transfected with pHook-1, which expresses a surface antigen, and a construct expressing MAP2. Transfected cells were selected with magnetic beads coated with a hapten that binds to the expressed surface antigen and treated with 150 microg/ml GM1 for 18-24 h. Actin and MAP2 or tubulin and MAP2 were immunolocalized and examined with confocal microscopy. MAP2 was found throughout the cytoplasm as well as associated with actin filaments. As observed previously with Neuro 2a, GM1 treatment of transfected fibroblasts redistributed the MAP2 away from direct association with microtubules to peripheral areas where the association of MAP2 with actin was enhanced. GM1 did not induce neurite-like processes in MAP2-transfected cells. Treatment with cytochalasin B, which is reported to result in process formation, also did not induce neurite-like processes. These studies suggest that GM1's ability to mobilize MAP2 and promote its association with actin is not restricted to neurons.

3T3 Cells↗
PubMed2000

Promotion of neurite outgrowth by protein kinase inhibitors and ganglioside GM1 in neuroblastoma cells involves MAP kinase ERK1/2.

To investigate mechanisms of neurite outgrowth, murine Neuro-2a neuroblastoma cells were exposed to ganglioside GM1 in the presence or absence of specific protein kinase inhibitors. Isoquinolinesulfonamide (H-89), an inhibitor of cyclic AMP dependent protein kinase A (PKA), and bisindolylmaleimide I (BIM), which inhibits protein kinase C, each stimulated neurite outgrowth in a dose-dependent manner in the absence of exogenous GM1. Minimally effective (threshold) concentrations of H-89 or BIM potentiated outgrowth when they were used in combination with GM1. To search for a shared component in the mechanisms of GM1, H-89 and BIM, phosphorylation of ERK1/2 was examined. Inhibition of the activation of extracellular signal regulated kinases (ERK1/2) by U0126, prevented neuritogenesis of Neuro-2a by all the three agents. Pretreatment of serum-depleted Neuro-2a cultures with GM1 or BIM enhanced ERK1/2 phosphorylation when the serum level was restored to 10%. In contrast, H-89 did not alter the serum-mediated response. In cells exposed to GM1 or BIM without additional serum, a transitory decrease in ERK phosphorylation occurred. These data suggest that GM1 influences two neuritogenic pathways, one modulated by PKC and the other regulated by PKA. Therefore, GM1 may have the potential to stimulate alternate pathways resulting in outgrowth.

Animals↗
PubMed1998

Ganglioside GM1 alters neuronal morphology by modulating the association of MAP2 with microtubules and actin filaments.

In previous studies, we demonstrated that the exogenous ganglioside GM1 increased the complexity of the microtubular network and level of tubulin, selectively changed the distribution of microtubule associated protein-2 (MAP2) immunoreactivity from the perikarya to distal neuritic processes and increased immunogold label of MAP2 in the subplasmalemmal cytoplasm, neuritic filopodia and growth cones of Neuro-2a neuroblastoma cells. Since these areas are rich in actin filaments, our data suggested that MAP2 may be associated with microfilaments in the early stages of ganglioside-induced neuritogenesis. To determine if GM1 alters neuronal morphology by facilitating the interaction of actin and MAP2, we examined the immunolocalization of these two proteins with confocal and electron microscopy. We found that along with the redistribution of MAP2 from perikaryal to neuritic regions, there was parallel redistribution of actin. The uniform subplasmalemmal actin meshwork was disrupted in areas of processes and filopodia with a redistribution of actin to these areas in close association with MAP2. Our present results suggest that gangliosides enhance neuritogenesis by redistributing actin as well as MAP2 to processes and filopodia thereby facilitating their interaction. The association of MAP2 with actin filaments is likely to be an early step in ganglioside-mediated filopodia formation.

Actins↗
PubMed1996

The ganglioside GM1 enhances microtubule networks and changes the morphology of Neuro-2a cells in vitro by altering the distribution of MAP2.

The effect of ganglioside GM1 on components of the neuronal cytoskeleton was studied in Neuro-2a neuroblastoma cells using immunofluorescent, immunogold-labeled, and Western-blot analysis. Exposure of cells to GM1 for 24 h resulted in an increased microtubular network and level of tubulin, a redistribution of MAP2 immunoreactivity from perikarya to distal neuritic processes, and an increased MAP2 gold label in the subplasmalemmal cytoplasm, neuritic spines, and growth cones. A similar change in the distribution of actin-positive fluorescent immunoreactivity was observed. In contrast to the redistribution of MAP2, immunolocalization of MAP5 and tau did not change following 24 h GM1 exposure. Our results suggest that gangliosides enhance neuritogenesis by selectively altering the distribution of MAP2 from perikaryon to neuritic spines. Furthermore, the enhanced presence of MAP2 in regions known to be rich in microfilaments following GM1 treatment suggests that an interaction of MAP2 with microfilaments may be necessary for early neurite formation.

Actins↗
PubMed1996

Assessment of lung auscultation by paramedics.

STUDY OBJECTIVE: To determine how accurately paramedics interpret common lung sounds on an audiotape in comparison with emergency physicians. METHODS: We carried out a prospective comparison of blinded lung sound interpretation using a standard teaching tape. Our subjects were 67 experienced paramedics and 22 new paramedics from urban and suburban emergency medical services systems comprising municipal and private ambulance providers; and 18 emergency physicians. Five common lung sounds were played three times, in different sequences, and with additional patient history provided for each repetition. The members of each group listened to the same tape and were asked to identify the lung sounds. RESULTS: Emergency physicians had a median score of five of five possible correct responses in each of the three trials. This score was significantly higher than those of experienced and new paramedics. Experienced paramedics (P = .001) and new paramedics (P = .002) significantly increased their median scores over the three trials with additional medical history. We found no significant difference between experienced and new paramedics in any of the three trials. CONCLUSION: In our study, paramedics did not assess lung sounds as accurately as emergency physicians, and experienced paramedics did not interpret sounds more accurately than new paramedics. Correct identification of lung sounds improved significantly for paramedics when medical history was known.

Auscultation↗
PubMed1995

Good steroid response in vivo predicts a favorable outcome in children with T-cell acute lymphoblastic leukemia. The Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP).

BACKGROUND: Improved outcome of children with acute lymphoblastic leukemia (ALL) who received intensive chemotherapy was observed by the Italian Association for Pediatric Hematology Oncology (AIEOP). To verify if this improved outcome was also extended to T-cell acute lymphoblastic leukemia (T-ALL) patients after introduction of intensive chemotherapy, treatment responses of 2011 patients, including 184 with T-ALL treated over the decade 1982-1991, were analyzed. Further, the potential use of the association of presenting clinical and biologic features with treatment outcome to determine risk factors that might be useful for planning risk-directed therapeutic studies was analyzed. METHODS: Of the 2011 children consecutively entered on the three sequential AIEOP trials ('82, '87, and '88), 1528 (76%) had successful immunologic studies of the bone marrow blasts. One hundred eighty-four (12%) had T-ALL. During these studies, four consecutive high-risk ALL treatment protocols (i.e., 8303, 8503, 8703, and 8803) were used. Because the treatment schedule in protocols 8503 and 8703 were almost identical, those patients were grouped together for the purpose of survival analysis. The 137 boys and 47 girls ranged in age from 16 months to 15.5 years (median, 7.8 years) at diagnosis, and 38% had a mediastinal mass. The rates of treatment response [i.e. complete remission (CR) and event free survival (EFS) rates] were compared for patients with T-ALL or B-cell progenitor ALL, overall and by individual study. Presenting features and early response to steroid monotherapy were also tested as possible prognostic factors. RESULTS: Overall, the CR rate was 94%, and the 7-year survival (SE) was 51.9% (4.2). T-ALL patients had a significantly worse outcome than B-lineage ALL patients [7-year EFS 40.4% (5.2) vs. 61.7% (1.7), P < 0.001]. Progressive improvement in EFS for T-ALL patients treated during 1 decade was observed, with 7-year EFS (SE) of 23.2% (8.3) for protocol 8303, 5-year EFS of 39.5% (7.1) for combined protocols 8503-8703, and 54.6% (7.1) for study '88, respectively. The analysis of prognostic factors for T-ALL patients showed that poor in vivo steroid response was the most unfavorable prognostic factor, followed by leukocyte level count > 50 x 10(9)/l (P = 0.04). The EFS for patients with T-ALL and good steroid response [63% (3.0)] was comparable with that of the unselected B-lineage ALL patients. CONCLUSIONS: EFS for patient with T-ALL has steadily increased in consecutive AIEOP ALL trials. However T-ALL patients still have a significantly worse EFS compared with patients with B-lineage ALL. Patients with T-ALL and a poor in vivo response to steroid monotherapy represent a particularly high risk treatment group.

Adolescent↗
PubMed1995

Cyclosporine therapy for refractory Langerhans cell histiocytosis.

Optimal treatment for Langerhans Cell Histiocytosis (LCH) has not yet been established. Preliminary reports suggest some effect of cyclosporine (CSA), both alone or in combination with steroids and/or vinblastine, in untreated cases. Twelve children (6 females and 6 males, age at diagnosis 3 months to 4 years) with biopsy proven, systemic LCH received oral CSA (12 mg/kg/day in two divided doses given daily) as a second-line therapy following chemotherapy including vinblastine and/or etoposide (10 cases) or steroid alone (one case); one child was not pretreated. A total of 16 CSA courses were administered to the 12 patients: 8 were completed, 4 were interrupted as unsuccessful, and 4 are still ongoing. CSA related toxicity consisted of hypertrichosis and transient hypertension and was never limiting. Treatment was associated with a clinical response in 8/12 patients: 3 had a complete response and are off therapy, and 5 had a partial response; disease reactivation following first favorable response required additional CSA courses in 3 patients. Four patients failed to respond to CSA: two died of progressive disease, while two had a favorable response to CSA + VP16. Favorable response to CSA was not related to CSA trough and peak levels and was usually observed during the first 2 weeks of CSA therapy. CSA is effective for treatment of LCH also in pretreated children with progressive disease including life-threatening organ dysfunction. Long-lasting complete remission may be achieved after 6 to 12 months of CSA therapy. When disease reactivation occurs after treatment withdrawal, a second course may be followed by favorable response. As minimal or no adverse effects are observed during or after prolonged CSA therapy, this may also be safely used in young patients.

Child↗
PubMed1995

Extended intrathecal methotrexate may replace cranial irradiation for prevention of CNS relapse in children with intermediate-risk acute lymphoblastic leukemia treated with Berlin-Frankfurt-Münster-based intensive chemotherapy. The Associazione Italiana di Ematologia ed Oncologia Pediatrica.

PURPOSE: To assess the effect of treatment intensification and that of extended intrathecal methotrexate substitution for cranial irradiation in intermediate-risk acute lymphoblastic leukemia (ALL) children treated with a Berlin-Frankfurt-Münster (BFM)-based intensive chemotherapy. PATIENTS: Three hundred ninety-six children with non-B-ALL were enrolled onto the Associazione Italiana di Ematologia ed Oncologic Pediatrica (AIEOP) ALL 88 study. Standard risk (SR) included patients with low tumor burden (BFM risk index [RI], < 0.8); intermediate risk (IR) were patients with an RI > or = 0.8 but less than 1.2; and high risk (HR) were those with an RI > or = 1.2 or CNS involvement at diagnosis. The treatment schedule was a modified version of the ALL-BFM 86 study. CNS-directed treatment consisted of high-dose methotrexate (HD-MTX; 5 g/m2 for four courses) plus intrathecal methotrexate (IT-MTX; nine doses); IR patients additionally received extended IT-MTX (nine doses during continuation therapy); cranial irradiation was given only to HR patients. RESULTS: Of the 375 (94.7%) children who achieved remission, 1.3% had an adverse event other than relapse. The estimated event-free survival (EFS) at 6 years was 66.6% (SE 2.4) overall; 80.7% (4.5) in the SR patients, 77.5% (3.9) in the IR patients, and 54.5% (3.7) in the HR patients. Relapse occurred in 107 children (27.0%). Isolated CNS relapse occurred in 20 children (5.0%): 5 (6.3%) in the SR group, 1 (0.8%) in the IR group, and 14 (7.1%) in the HR group. The estimated 6-year CNS leukemia-free survival was 94.6% (1.2) overall: 93.5% (2.8) in the SR group, 99.1% (0.9) in the IR group, and 92.3% (2.0) in the HR group. CONCLUSION: Cranial irradiation may be omitted safely in IR ALL patients treated with BFM-based intensive chemotherapy when extended intrathecal chemotherapy is given. Because the CNS disease control was less complete in the SR group, these data challenge the effectiveness of HD-MTX for protection from CNS disease and support the protective role of extended intrathecal chemotherapy.

Adolescent↗
PubMed1994

Localization of cystatin mRNA in chicken brain by in situ hybridization.

The cystatins are a superfamily of proteins that inhibit the lysosomal cysteine proteinases, cathepsins B, H, and L. Members of this superfamily have been found in all tissues and biological fluids analyzed. Previous studies have shown that chicken cystatin mRNA is abundant in brain tissue. In this study, a definitive localization of chicken cystatin mRNA in chicken brain was determined by in situ hybridization. Chicken cystatin mRNA was heavily concentrated in the secretory epithelial cells of the choroid plexus. The rest of the brain failed to show a hybridization signal above that of the control sense strand probe, even after long exposures. We conclude that chicken cystatin is synthesized predominantly by the specialized secretory epithelial cells of the choroid plexus and secreted into the cerebrospinal fluid (CSF). We postulate that chicken cystatin functions to regulate proteinase activity in the CSF and therefore may function as a protective factor for the cellular elements of the central nervous system.

Animals↗
PubMed1993

Isolation and characterization of the chicken cystatin-encoding gene: mapping transcription start point and polyadenylation sites.

A 6.9-kb fragment containing coding sequences for chicken egg white cystatin (CsnEW) was isolated from a chicken genomic library using the CsnEW cDNA as a probe. The gene is approximately 2.4 kb in length; it contains three exons, two introns and two polyadenylation signals. The exon-intron arrangement corresponds exactly with those of other members of the Csn superfamily. The sequence of the 5' flanking region contains two SP1-binding sites and a high G+C content suggestive of a housekeeping gene. All tissues studied express CsnEW mRNA; Northern analysis showed that CsnEW mRNA levels are most abundant in lung and least abundant in liver and spleen. Mapping of the 3' end of the CsnEW mRNA isolated from brain tissue resolved two CsnEW mRNA species. The larger transcript resulting from the use of the second polyadenylation signal was more abundant than the smaller transcript. Determination of the transcription start point (tsp) of CsnEW mRNA by primer extension and RNase protection assays showed that CsnEW mRNA from a number of chicken tissues was approximately 40-50 nucleotides shorter than that predicted from the CsnEW cDNA isolated from chicken oviduct.

Amino Acid Sequence↗