Search PubMed⌕ Search

Biomedical subjects

P Ricci

Publications and source records attributed to P Ricci.

At least 73 records · Page 4Linked to original sources
PubMed1995

Evidence for specific, high-affinity binding sites for a proteinaceous elicitor in tobacco plasma membrane.

Binding of cryptogein, a proteinaceous elicitor, was studied on tobacco plasma membrane. The binding of the [125I]cryptogein was saturable, reversible and specific with an apparent Kd of 2 nM. A single class of cryptogein binding sites was found with a sharp optimum pH for binding at about pH 7.0. The high-affinity correlates with crytogein concentrations required for biological activity in vivo.

Algal Proteins↗
PubMed1995

Elicitin produced by an isolate of Phytophthora parasitica pathogenic to tobacco.

Elicitin was prepared from a Phytophthora parasitica culture isolated from tobacco in Australia. The protein with elicitor activity was purified and sequenced. This protein, which contains 98 amino acid residues, shows full homology with an elicitin produced by a completely unrelated isolate from carnation, indicating conservation of elicitin sequence within a single species.

Amino Acid Sequence↗
PubMed1995

Fatal haemoptysis in pulmonary filamentous mycosis: an underevaluated cause of death in patients with acute leukaemia in haematological complete remission. A retrospective study and review of the literature. Gimema Infection Program (Gruppo Italiano Malattie Ematologiche dell'Adulto)

A retrospective study on a consecutive series of 116 patients affected by acute leukaemia with documented pulmonary filamentous mycosis (FM) admitted between 1987 and 1992 to 14 tertiary-care hospitals in Italy was made in order to evaluate the characteristics of those patients who developed fatal massive haemoptysis. In 59/116 cases of pulmonary FM the infection was the principal cause of death and in 12 of these patients a massive haemoptysis was responsible for death. The diagnosis of FM infection was made ante-mortem in only four out of these 12 patients. The autopsy was performed in 11/12 patients and documented a FM infection. The mycetes isolated were: Hyphomycetes spp. (three patients), Mucorales spp. (two patients), Aspergillus spp. (seven patients). At the time of the massive haemoptysis the mean neutrophil count was 7.2 x 10(9)/l, and no patient had relevant thrombocytopenia (mean 184 x 10(9)/l, range 28-350) or coagulative abnormalities. The mean time which elapsed between resolution of chemotherapy-induced neutropenia (WBC < 10(9)/l) and occurrence of haemoptysis was 7 d. No signs or symptoms predictive of this fatal complication were identified. Massive haemoptysis can be the cause of death in patients with acute leukaemia and pulmonary FM which in the majority of patients was not diagnosed in vivo. This complication occurs most frequently shortly after the recovery from chemotherapy-induced aplasia. The mechanism of lesion is unknown, but it may involve the vascular tropism of FM and the release of leucocyte enzymes. Better preventive and therapeutic antifungal treatments are needed to avoid this serious, albeit rare, complication.

Acute Disease↗
PubMed1995

[Budd-Chiari syndrome in children: case report].

This work aims at describing a particular case of Budd-Chiari syndrome in a ten-year-old girl. In our patient, the subjective and objective features of this disease, which is already rare during childhood, are associated with a well-assessed polyposis in the blind intestine (intestinum caecum). In our opinion, a possible connection between these two pathological events, a connection unheard of in the literature so far, is an interesting issue to be dealt with in this case report. The follow-up of our patient took place at the Pediatric Hospital of the University of Rome "La Sapienza" and lasted an overall period of 6 months. The girl was hospitalized twice and she underwent a large number of radiological and laboratory tests. The therapy consisted only of medical treatment and support measures. Liver transplant is regarded as the only chance to obtain a full recovery, but it has not yet been performed on our patient. It is by comparing those researches carried out on similar cases with the outcome of our personal study, that we come to the conclusion that, as for our patient, the Budd-Chiari syndrome can be classified as an idiopathic syndrome. Moreover, the fact that this syndrome and the polyposis of caecum occur at the same time in a patient can probably be considered as a coincidence.

Budd-Chiari Syndrome↗
PubMed1994

Preventing fungal infection in neutropenic patients with acute leukemia: fluconazole compared with oral amphotericin B.

OBJECTIVE: To compare the efficacy and tolerability of fluconazole and oral amphotericin B in preventing fungal infection in neutropenic patients with acute leukemia. DESIGN: A randomized, controlled, multicenter trial. SETTING: 30 hematologic units in tertiary care or university hospitals. PATIENTS: 820 consecutive, afebrile, adult patients with acute leukemia and chemotherapy-induced neutropenia. INTERVENTION: Patients were randomly assigned to receive fluconazole, 150 mg, as a once-daily capsule, or amphotericin B suspension, 500 mg every 6 hours. MEASUREMENTS: An intention-to-treat analysis was done for 820 patients: 420 treated with fluconazole and 400 treated with oral amphotericin B. RESULTS: Definite systemic fungal infection occurred in 2.6% of fluconazole recipients and 2.5% of amphotericin B recipients; suspected systemic fungal infection requiring the empiric use of intravenous amphotericin B occurred in 16% of fluconazole recipients and 21% of oral amphotericin B recipients, a difference of 5 percentage points (95% CI for difference, -0.02% to 10%; P = 0.07). Superficial fungal infection was documented in 1.7% of fluconazole recipients compared with 2.7% of amphotericin B recipients, a difference of one percentage point (CI of difference, -0.9% to 3%; P > 0.2). The distribution of fungal isolates in systemic and superficial fungal infection was similar in both groups. The overall mortality rate accounted for 10% in both groups. An excellent compliance was documented for 90% of patients treated with fluconazole compared with 72% of those treated with amphotericin B suspension, a difference of 18 percentage points (CI for difference, 13% to 23%). Side effects were documented less frequently in fluconazole than in amphotericin B recipients (1.4% compared with 7%, a difference of 5.6 percentage points; CI for difference, 2% to 8%; P < 0.01). CONCLUSION: Fluconazole was at least as effective as oral amphotericin B in preventing systemic and superficial fungal infection and the empiric use of amphotericin B in neutropenic patients with acute leukemia but was better tolerated.

Acute Disease↗
PubMed1994

Effects of teicoplanin and those of vancomycin in initial empirical antibiotic regimen for febrile, neutropenic patients with hematologic malignancies. Gimema Infection Program.

The efficacy and toxicity of teicoplanin and vancomycin in the initial empirical antibiotic regimen in febrile, neutropenic patients with hematologic malignancies were compared in a prospective, randomized, unblinded, multicenter trial in the setting of 29 hematologic units in tertiary-care or university hospitals. A total of 635 consecutive febrile patients with hematologic malignancies and chemotherapy-induced neutropenia were randomly assigned to receive intravenously amikacin plus ceftazidime plus either teicoplanin at 6 mg/kg of body weight once daily or vancomycin at 1 g twice daily. An efficacy analysis was done for 527 evaluable patients: 275 treated with teicoplanin and 252 treated with vancomycin. Overall, successful outcomes were recorded for 78% of patients who received teicoplanin and 75% of those who were randomized to vancomycin (difference, 3%; 95% confidence interval [CI], -10 to 4%; P = 0.33). A total of 102 patients presented with primary, single-agent, gram-positive bacteremia. Coagulase-negative staphylococci accounted for 42%, Staphylococcus aureus accounted for 27%, and streptococci accounted for 21% of all gram-positive blood isolates. The overall responses to therapy of gram-positive bacteremias were 92 and 87% for teicoplanin and vancomycin, respectively (difference, 5%; CI, -17 to 6%; P = 0.22). Side effects, mainly represented by skin rash, occurred in 3.2 and 8% of teicoplanin- and vancomycin-treated patients, respectively (difference, -4.8%; CI, 0.7 to 8%; P = 0.03); the rate of nephrotoxicity was 1.4 and 0.8% for the teicoplanin and vancomycin groups, respectively (difference, 0.6%; CI, -2 to 1%; P = 0.68). Further infections were caused by gram-positive organisms in two patients (0.7%) treated with teicoplanin and one patient (0.4%) who received vancomycin (difference, 0.3%; CI, -0.9 to 1.0%; P = 0.53). Overall mortalities were 8.5 and 11% for teicoplanin- and vancomycin-treated patients, respectively (difference, -2.5%; CI, - 2 to 7%; P = 0.43); death was caused by primary gram-positive infections in three patients (1%) in each treatment group. When used for initial empirical antibiotic therapy in febrile, neutropenic patients, teicoplanin was at least as efficacious as vancomycin, but it was associated with fewer side effects.

Adolescent↗
PubMed1994

[Carbon dioxide as an intra-arterial contrast agent in echography: a technic for its preparation and the preliminary results in assessing hepatocarcinoma vascularization].

This paper reports on an original method to prepare a contrast agent consisting of CO2 microbubbles to be injected i.a. during ultrasound examinations (ultrasound angiography-USA), whose value was investigated in the study of tumor neovascularity in HCC patients. Thirty-five HCC patients underwent USA. CO2 was drawn out from a gas container under pressure and, through a sublimation process, made available in predetermined quantities in test tubes. USA was performed during angiography in 9 cases and immediately before arterial chemoembolization in the other 26 cases. In 51 lesions vascularity was evaluated with conventional angiography, USA and lipiodol CT. USA demonstrated lesion hypervascularity in 91% of cases, as confirmed by lipiodol CT (88%), versus 72.4% of angiography. In 3 of 35 patients USA demonstrated 6 more lesions undetected by other modalities: two of them were proved to be HCC and adenomatous hyperplasia at percutaneous biopsy. USA is a cost-effective procedure, which is easy to perform during conventional angiography: it is more sensitive than conventional angiography in the study of lesion neovascularity and can help plan lesion management, anticipating the results of chemoembolization. The role of USA in the diagnosis and treatment of HCC is, however, still to be defined.

Aged↗
PubMed1994

[Transjugular intrahepatic porto-systemic shunt (TIPS): indications and results].

This study was aimed at describing some technical features of the transjugular portosystemic shunt (TIPS). December 1991 to November 1993, fifty-five TIPS were performed in our department. The right internal jugular vein, which is the most direct path to the inferior vena cava, was punctured in 48 cases, the left one in seven cases. The right suprahepatic vein was catheterized in 43 cases, and the median suprahepatic vein in 12 cases. The puncture of the portal vein was performed in 21 cases in the right portal branch, in the left one in 23 cases, and in the portal bifurcation in 11 cases. In all cases in which the puncture site was questionable, an X-ray exam with lateral or oblique projection was performed, to be sure that the needle had entered the intrahepatic portion of the portal vein. A landmark to locate the portal system, such as a catheter in the hepatic artery, a skin landmark or a metallic coil near the porta, were positioned in 30 patients. Particularly, in 20 patients, a 0.018-inch guidewire with platinum tip was placed at the bifurcation; in seven cases a 3F catheter was advanced over the guidewire, to visualize the portal bifurcation directly with contrast medium injection. In our experience, a total number of 83 stents were positioned in 55 patients: 53 Wallstents, 13 Palmaz stents, and 17 Strecker-Nitinol stents. One single stent was placed in 31 patients, two stents in 21 patients, three stents in two patients, and, finally, four stents were positioned in one patient. In our series the technical success rate was 100%. The use of a metallic landmark significantly decreased procedures duration, ranging 40 minutes to 2 hours, and, above all, it allowed for significantly fewer puncture attempts, which varied from a minimum of 1-2 in 80% of cases, to a maximum of 20 especially in these patients with ascitis and with small and hard liver.

Procedural Sedation↗
PubMed1994

Mg deficiency induces mineral content changes and oxidative stress in rats.

We have studied the effect of Mg deficiency on both tissue mineral content and liver oxidative status. Male Wistar rats kept for eight weeks on a Mg-deficient diet (Mg 152ppm) quickly developed a severe plasma Mg deficiency (73% decrease). The content of Cu and Fe significantly increased in different tissues following the treatment. Liver glutathione, CuZn-superoxide dismutase, and vitamin E were significantly reduced (by about 16%, 18% and 30% respectively). Lipid peroxidation, induced in vitro by NADPH/ADP-Fe3+ and measured as MDA formation, increased by about 100% after 20 min incubation in liver microsomes isolated from Mg-deprived rats. The alterations found in the content of transition metals and in the level of both cytosolic and membrane antioxidants, as well as the higher sensitivity of liver microsomes to lipid peroxidation in vitro, are consistent with an oxidative stress occurring in vivo in the tissues of Mg-deficient animals.

Adenosine Diphosphate↗
PubMed1994

Protection and revascularization of bronchial anastomoses by the intercostal pedicle flap.

We used an improved method for preparation of the intercostal pedicle flap for encircling bronchial anastomoses, and we studied its vascular supply after the operation. The flap was used in 56 patients undergoing various types of sleeve resection and in three patients undergoing single lung transplantation. The technique is simple, fast, and causes neither extra surgical trauma nor complications. It allows satisfactory isolation and sealing of the bronchial anastomosis. Even if complete anastomotic dehiscence occurs (one case), the flap preserves the continuity of the airway, thus avoiding bronchopleural fistulas or other complications. The postoperative arteriographic study of the intercostal artery supplying the flap (performed in 14 patients) demonstrated the full patency of the vessel in all cases. It also showed that a fine vascular network develops around the anastomosis early in the postoperative period.

Anastomosis, Surgical↗
PubMed1993

tert-butyl hydroperoxide induced [Ca2+]i increase in thymus and thymoma cells.

The effect of tert-butyl hydroperoxide (t-BOOH) on Ca2+ homeostasis in tumor thymocytes in comparison to normal thymus cells has been studied. t-BOOH induces an early Ca2+ increase which shows different kinetic and extent in normal and tumor thymocytes. However, evidence is reported that in both types of cells it is just an epiphenomenon not directly related to late injury event. The different effects of various compounds (EGTA, dithiothreitol, deferoxamine and glucose) on the early Ca2+ increase and the late LDH release induced by t-BOOH suggest the occurrence, only in tumor cells, of some undefined deleterious process related to Ca2+ movements.

Animals↗
PubMed1993

[Metallic stents in benign biliary stenosis. A four-year follow-up].

From October 1988 to September 1989, 29 self-expanding biliary metallic stents were positioned in 18 patients with recurrent benign biliary strictures, who were no longer candidates to surgical repair and did not respond to percutaneous balloon dilatation. "Z" stent were used in 17 patients and a Wallstent in one case. At four years' follow-up (range: 39-50, average: 46 months), 10 patients remain asymptomatic, without signs of bile stasis (55.5%), five patients had recurrence of symptoms and were subsequently retreated (27.7%) and three patients died from severe underlying diseases, two of them with stent obstruction, one without signs of bile stasis. Recurrences were caused by stent obstruction in three cases. At four years' follow-up the overall patency rate is 68.7%. According to the type of stricture treated, patency is 100% in the group of patients with single CBD stenosis and in the patients with single anastomotic strictures, whereas in all patients with multiple or complicated strictures the stents completely occluded within 4-22 months.

Adult↗
PubMed1993

[Percutaneous treatment of symptomatic renal cysts: effects of the combination of sclerotherapy with alcohol and fibrin glue (tissucol)].

The percutaneous treatment of symptomatic renal cysts has grown in therapeutic importance over the last years. The international literature includes many reports on the sclerotherapy of renal cysts with different sclerosing agents. The authors report their experience with the percutaneous treatment of renal cysts by combining pure alcohol and fibrin glue. The glue serves the purpose to seal the walls of the cyst already damaged by alcohol. The results of the combined treatment show that relief of symptoms was obtained in all patients, with no major or minor complications. Complete cyst ablation was obtained only in 16% of cases, while a partial recurrence was seen in 80% of patients, with an average regrowth < 35% of the initial cyst volume. None of these patients presented further symptoms. At present, the follow-up time ranges 3 to 34 months.

Adolescent↗
PubMed1992

Some ribosome-inactivating proteins depurinate ribosomal RNA at multiple sites.

Saporin-S6, a ribosome-inactivating protein (RIP) from Saponaria officinalis released more than 1 mol of adenine/mol of ribosomes from house fly (Musca domestica) larvae and from rat liver. The release of adenine from rat liver ribosomes by several RIPs (plant enzymes with RNA N-glycosidase activity) was examined. Saporins, pokeweed antiviral protein from roots of Phytolacca americana (PAP-R), and trichokirin from Trichosanthes kirilowii seeds depurinated rat liver ribosomes at more than one site. Up to 33 mol of adenine were released from 1 mol of ribosomes. This property is not common to all RIPS.

Animals↗