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R Roberti

Publications and source records attributed to R Roberti.

47 records · Page 3Linked to original sources
PubMedDate not supplied

Factors affecting the stability of detergent-solubilized cholinephosphotransferase and ethanolaminephosphotransferase.

Cholinephosphotransferase (CPT) and ethanolaminephosphotransferase (EPT) are the enzymes catalyzing the last step of the de novo pathway for phosphatidylcholine and phosphatidylethanolamine synthesis, respectively. A major limitation for the complete characterization of the reactions catalyzed by the two enzymes derives from their poor stability in detergent-containing buffers. CPT is heavily inactivated, when native membranes are solubilized using a series of detergents, whereas EPT activity is better preserved during solubilization. An investigation of the factors which could play a role in preserving both enzymes from inactivation was carried out. The dramatic loss of enzymatic activities occurring upon dilution of solubilized membranes with detergent-containing buffers can be reduced by supplementing the dilution medium with phospholipids. The addition of Mn2+ ions to the dispersion buffer increases the stability of both enzymes. The procedure previously described for solubilizing EPT from rat brain microsomes has been modified on the basis of this evidence. Microsomes were solubilized in buffered detergent solutions containing Mn2+ ions and both CPT and EPT were partially purified in their active form by anion-exchange chromatography.

Animals↗
PubMedDate not supplied

[Isolated peripheral arterial ischaemia and medullary neurostimulation: case report].

Isolated peripheral arterial ischaemia (IPAI) is an unusual pathology of dialysis and peritoneal patients which represents the first sign of a complication of uraemia known as calciphylaxis. Recent studies have revealed an increased incidence of this complication. Risk factors are known but there is no consensus on them: elevated CaxP product, female gender, elevated serum parathormone. We present here the case of a 65-year-old man with 21-year history of dialysis, distal isolated ulceration and without any signs of severe vasculopathy. Our clinical diagnosis was calciphylaxis. In this case, the role of early PTX is not clear and the use of steroids is recommended only in non-ulcerating cases. The therapy gives good results but not in all patients. Electrical stimulation of the posterior roots of the spinal cord is an alternative approach to this case. We hypothesised that the electrical action, through cutaneous vasodilatation of afferent dorsal fibres and release of calcitonin gene-releasing protein, determines the release of prostaglandin E sub 2 that may positively affect the proliferation and activity of epidermal fibroblasts.

Afferent Pathways↗
PubMedDate not supplied

Photoparoxysmal response on eye closure in photosensitive patients.

The Authors studied the presence of photoparoxysmal response (PPR) during intermittent photic stimulation (IPS) in 2,888 consecutive EEG recordings. PPR was present in 2.3% of EEGs and 10% of all patients referred to EEG laboratory for epilepsy (45 patients, 18 males, 27 females (M:F ratio 1:1.5), mean age 12 yrs). In 24 (53.3%) of these patients PPR was evident only (24.4%) or strikingly (28.9%) on eye closure during IPS. In 7 patients no other epileptic abnormalities were found on basal EEG and during hyperventilation, nor during IPS with eyes closed and with eyes open. The Authors consider the eye closure during IPS the most useful method to reveal a PPR in photosensitive patients and believe that a good IPS technique must include this procedure in the routine EEG examination.

Child↗
PubMedDate not supplied

[Pulmonary infiltrate-eosinophilia syndrome. Description of a case].

Pulmonary infiltrates associated with eosinophilia can be found in a variety of hypersensitivity infections, toxic, autoimmune, granulomatous, and malignant conditions. In this paper a case is described and its clinical, laboratory, radiological, and histological aspects are discussed in order to pose a differential diagnosis.

Adult↗