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R Graziani

Publications and source records attributed to R Graziani.

At least 37 records · Page 2Linked to original sources
PubMed1994

Nonradioactive receptor binding assay for ciliary neurotrophic factor.

A nonradioactive receptor binding assay for ciliary neurotrophic factor (CNTF) is described. The assay is based on the interaction between biotinylated human CNTF, soluble gp130, and soluble myc-tagged CNTF receptor captured on a microtiter plate via an antibody against the myc epitope tag. Bound cytokine is revealed by alkaline phosphatase-conjugated avidin. Purified human and rat CNTF competed with biotinylated CNTF for receptor binding, with IC50 values of 29 and 2 nM, respectively. Since the higher affinity of rat vs human CNTF has been previously shown to be conferred by the arginine residue at position 63 of the rat protein, we also tested a human CNTF mutant carrying a Q63R substitution. Secreted forms of wild-type and mutant CNTF were expressed in Escherichia coli, and the amount of cytokines in periplasmic extracts was determined by quantitative Western blotting analysis. The human CNTF mutant (Q63R, N137S) was found to compete with biotinylated CNTF for binding to soluble CNTF receptor with an eightfold higher apparent affinity than wild-type human CNTF. The present method thus faithfully reproduces the relative activities of CNTF analogs determined in other assay systems. The possibility of assaying cytokines in crude bacterial extracts makes the new technique particularly suitable for rapidly determining the receptor binding potencies of genetically engineered CNTF variants.

Amino Acid Sequence↗
PubMed1994

Production and structural characterization of amino terminally histidine tagged human oncostatin M in E. coli.

Oncostatin M is a cytokine that acts as a growth regulator on a wide variety of cells and has diverse biological activities including acute phase protein induction, LDL receptor up-regulation and cell-specific gene expression. In order to gather information about the Onc M structure, we established a protocol for large scale production and single step purification of this functional cytokine from bacterial cells. The cDNA of human Onc M was cloned by RT-PCR from total RNA of PMA induced U937 cells. After the addition of a six histidine tag at the N-terminus, the coding region of mature Onc M was cloned in the pT7.7 expression vector. Histidine tagged Onc M was overexpressed in bacterial cells and purified to homogeneity in one step on a metal chelating column. We found that recombinant 6xHis-OncM remains fully active in a growth inhibition assay. Structural characterization of the purified protein was performed by electrospray mass spectrometry, automated Edman degradation and peptide mapping by high-pressure liquid chromatography/fast-atom-bombardment mass spectrometry. Thermal and pH stability dependence of Onc M was assessed by circular dichroism spectroscopy; the helical content is about 50%, in agreement with the four helix bundle fold postulated for cytokines that bind haematopoietic receptors of type I.

Amino Acid Sequence↗
PubMed1994

Sudden death in diabetic subjects: evidence for a peculiar circadian variation in occurrence.

Anatomo-physiopathological and chronobiological features of 59 diabetic subjects out of 610 non hospitalized individuals observed for sudden death (SD) in an Emergency Room, over an 8-year period, were studied. Mean age and anatomopathological causes of SD were not different between diabetic (DMs) and non-diabetic subjects (NDs). However the frequency of DMs was higher among subjects who died from circulatory failure death (CFD), rather than from arrhythmic death (AD). Diabetics presented a prevalent peak incidence of SD in the afternoon-late evening; whereas in NDs two peaks were present, respectively in the morning and in the afternoon. According to anatomo-physiopathological causes, DMs presented a higher incidence of acute myocardial infarction (AMI) and CFD between 21:01 and 24:00, whereas in NDs the prevalent peak of AMI was observed in the early afternoon (13:01 to 16:00). Moreover, in DMs SD from acute myocardial failure prevalently occurred in the early afternoon (13:01 to 16:00), whereas in NDs it was uniformly distributed throughout the day. The present study seems to indicate that different anatomo-physiopathological causes of SD may present specific temporal patterns in diabetics.

Circadian Rhythm↗
PubMed1992

[Invasive pulmonary aspergillosis: possibility of radiologic diagnosis].

The incidence of invasive pulmonary aspergillosis is increasing in the patients with malignant hematologic diseases; this occurs in the phase of granulocytopenia induced by chemotherapy. In these cases an early diagnosis is mandatory to start a prompt antimycotic treatment. The authors reviewed the personal series of 56 patients with malignant hematologic diseases who, in the phase of granulocytopenia, developed a pulmonary lesion: 32/56 with invasive pulmonary aspergillosis; 8/56 with Candida and 16/56 with bacterial infection. All patients underwent several conventional radiologic controls: 9 cases with invasive pulmonary aspergillosis were also studied with Computed Tomography (CT). After a short pathologic introduction, the conventional radiologic and CT patterns of invasive pulmonary aspergillosis are analyzed, both at onset and over its evolutive phase. The most significant feature for an early conventional radiologic diagnosis is the nodular pattern--single or multiple--; this allowed a correct diagnosis, at onset, of 20/32 (62%) invasive pulmonary aspergillosis cases. CT provided a further diagnostic contribution by showing a peri-nodular halo. Of interest was also the CT demonstration of high-density pleural thickening adjacent to the mycotic lesion, probably due to fungal involvement of the sub-pleural space. The routine chest roentgenogram is the modality of choice; CT may be useful in questionable cases.

Aspergillosis↗
PubMedDate not supplied

Serous cystadenoma of the pancreas: report of 30 cases with emphasis on the imaging findings.

PURPOSE: Our goal was to evaluate retrospectively 30 cases of serous cystadenoma (SCA) to determine its main imaging features as well as to discuss the differential diagnosis problems versus the other cystic lesions of the pancreas. METHOD: Thirty SCAs were analyzed; they were all benign lesions, proven at surgery. Twenty-three tumors were evaluated with US, 26 with CT, and 5 with MRI. RESULTS: Three different morphostructural patterns were identified: microlacunar (n = 19), mixed (n = 6), and macrolacunar (n = 5). The diagnosis of SCA, possible in either the microlacunar or the mixed patterns, was achieved in 74% of cases with US (17/23) and in 61.5% with CT (16/26). Among the 19 patients evaluated with both modalities, the joint information allowed a correct diagnosis in 16 cases (84%). The five macrolacunar tumors were undistinguishable from other cystic masses of the pancreas. CONCLUSION: The diagnosis of SCA can be considered certain in the microlacunar, likely in the mixed, and not possible in the macrolacunar type.

Adolescent↗
PubMedDate not supplied

Papillary cystic neoplasm of the pancreas: radiological findings.

We report a series of 10 papillary cystic neoplasms of the pancreas evaluated in our institution. The lesions are analyzed in retrospect to define the existence of eventual specific imaging patterns as well as to point out the existing problems of differential diagnosis versus other pancreatic tumors.

Adolescent↗