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Biomedical subjects

P Ricci

Publications and source records attributed to P Ricci.

At least 19 recordsLinked to original sources
PubMed1997

The fungal elicitor cryptogein is a sterol carrier protein.

Cryptogein is a protein secreted by the phytopathogenic pseudo-fungus, Phytophthora cryptogea. It is a basic 10 kDa hydrophilic protein having a hydrophobic pocket and three disulfide bridges. These common features with sterol carrier proteins led us to investigate its possible sterol transfer activity using the fluorescent sterol, dehydroergosterol. The results show that cryptogein has one binding site with strong affinity for dehydroergosterol. Moreover, this protein catalyzes the transfer of sterols between phospholipidic artificial membranes. This is the first evidence for the existence of an extracellular sterol carrier protein and for a molecular activity of cryptogein. This property should contribute to an understanding of the role of cryptogein in plant-microorganism interactions.

Algal Proteins↗
PubMed1997

A prognostic model for the outcome of liver transplantation in patients with cholestatic liver disease.

We studied the outcome of 436 patients with primary biliary cirrhosis (PBC) or primary sclerosing cholangitis (PSC) who underwent orthotopic liver transplant (OLT) at three major liver transplant centers. Univariate predictors of outcome included age, Karnofsky score, Child's class, Mayo risk score, United Network for Organ Sharing (UNOS) status, nutritional status, serum albumin, serum bilirubin, international normalized ratio, and the presence of ascites, encephalopathy, renal failure (serum creatinine > 2 mg/dL), and edema refractory to diuretics. Using these predictors, we developed a four variable mathematical prognostic model to help the liver transplant physician predict the following: 1) the amount of intraoperative blood loss; 2) the number of days in the intensive care unit (ICU); and 3) severe complications after surgery. The model uses age, renal failure, Child's class, and United Network for Organ Sharing status. This study is the first to model the outcome of liver transplant in patients with a specific etiology of chronic liver disease (PBC or PSC). The model may be used to help select patients for OLT and to plan the timing of their transplantation.

Analysis of Variance↗
PubMed1997

Antioxidant and prooxidant role of beta-carotene in murine normal and tumor thymocytes: effects of oxygen partial pressure.

The effects of the partial pressure of oxygen (pO2) on antioxidant efficiency of beta-carotene in inhibiting radical-initiated lipid peroxidation were studied in murine normal and tumor thymocytes. At 150 mm Hg pO2 (the pressure of oxygen in normal air), beta-carotene acted as an antioxidant, inhibiting radical-induced lipid peroxidation in both normal and tumor thymocytes. At 760 mm Hg p02, beta-carotene lost its antioxidant activity in normal thymocytes and exhibited a dose-dependent prooxidant effect in tumor thymocytes. In these cells, the prooxidant effect of beta-carotene was also accompanied by an increase of endogenous alpha-tocopherol loss. beta-Carotene radical-trapping and autooxidation reactions were faster at 760 mm Hg pO2 than at 150 mm Hg pO2 in both normal and tumor thymocytes and the carotenoid was more rapidly consumed in tumor cells. These data point out a key role of the oxygen tension on the antioxidant effectiveness of beta-carotene. They also show a selective prooxidant effect of beta-carotene under 100% oxygen in tumor cells.

Amidines↗
PubMed1997

Nongastrointestinal mucosa-associated lymphoid tissue (MALT) lymphomas: clinical and therapeutic features of 24 localized patients.

BACKGROUND: Peripheral B-cell lymphoma of the marginal zone (MALT, low-grade), presenting as localized, extranodal disease, usually affects the elderly. The gastrointestinal tract is the most frequently involved extranodal location, representing 70% of all MALT lymphomas. Recently, numerous other extranodal sites involved by MALT lymphomas have also been described. PATIENTS AND METHODS: From January 1990 to October 1995, 24 patients with untreated nongastrointestinal low-grade MALT lymphoma were submitted to treatments ranging from the local approach of radiotherapy and local alpha-interferon (alpha-IFN) administration to chemotherapy. The tumours were located in the lung (seven cases), conjunctiva (four cases), lachrymal gland and orbital soft tissue (four cases), salivary glands (three cases), skin (three cases), breast (two cases), and thyroid (one case). All patients had low-grade stage IE tumours. RESULTS: Chemotherapy was administered in 11 patients (six with lung, three with salivary gland, one with breast, and one with thyroid locations); radiation therapy was employed in seven patients (three with lachrymal gland, three with skin, and one with breast locations); local alpha-IFN administration was administered in five patients (four with conjunctival, and one with lachrymal gland sites); and surgery was employed in one patient with a lung tumour. All patients achieved complete remissions; three local recurrences and two relapses in other sites were observed. The global five-year survival rate was 100% with a relapse-free survival rate of 79%. CONCLUSIONS: These data confirm the significant efficacy of different therapeutic approaches to specific sites inbes obtaining a good remission rate for nongastrointestinal localized low-grade MALT lymphomas.

Adult↗
PubMed1997

Mucormycosis in patients with haematological malignancies: a retrospective clinical study of 37 cases. GIMEMA Infection Program (Gruppo Italiano Malattie Ematologiche Maligne dell'Adulto).

A retrospective study of 37 patients with haematological malignancy (21 acute myeloid leukaemia, 11 acute lymphoid leukaemia, two lymphoma, two hairy cell leukaemia, one Hodgkin's disease) and histologically documented mucormycosis was conducted to evaluate the clinical characteristics and ascertain the factors which influenced the outcome from mycotic infection. Patients were admitted to 18 haematology divisions in tertiary care or university hospitals in Italy between 1987 and 1995. Fever, thoracic pain, dyspnoea and cough were the most frequent presenting symptoms. At the onset, 89% patients were neutropenic (neutrophil counts < 0.5 x 10(9)/l) with a median duration of previous neutropenia of 14 d (range 6-60). The most frequent sites of infection were lungs (81%), CNS (27%), sinus (16%), liver (16%) and orbital space (10%). Only three patients were asymptomatic. A correct in vivo diagnosis was made in only 13 (35%) patients. When performed, thoracic and cranial CT scan were the most useful diagnostic investigations. Despite the fact that 26 febrile patients were treated with empirical antifungal treatment, 28 of the 37 patients (76%) died from fungal infection at a median time of 17 d from the onset of clinical symptoms. Nine patients were cured by antifungal therapy plus, in five cases, radical surgery procedures. An analysis of factors influencing outcome demonstrated that the resolution of chemotherapy-induced neutropenia and prolonged treatment with amphotericin B and, if feasible, radical surgical debridement treatment, were significantly correlated with recovery from infection. Mucormycosis, a rare filamentous fungal infection that occurs most frequently in neutropenic acute leukaemia patients, is characterized by a high mortality rate. Extensive and aggressive diagnostic and therapeutic procedures are essential to improve the prognosis in these patients.

Adolescent↗
PubMed1997

RNase activity prevents the growth of a fungal pathogen in tobacco leaves and increases upon induction of systemic acquired resistance with elicitin.

The hypersensitive response and systemic acquired resistance (SAR) can be induced in tobacco (Nicotiana tabacum L.) plants by cryptogein, an elicitin secreted by Phytophthora cryptogea. Stem application of cryptogein leads to the establishment of acquired resistance to subsequent leaf infection with Phytophthora parasitica var nicotianae, the agent of the tobacco black shank disease. We have studied early events that occur after the infection and show here that a tobacco gene encoding the extracellular S-like RNase NE is expressed in response to inoculation with the pathogenic fungus. Upon induction of SAR with cryptogein, the accumulation of NE transcripts coincided with a rapid induction of RNase activity and with the increase in the activity of at least two different extracellular RNases. Moreover, exogenous application of RNase activity in the extracellular space of leaves led to a reduction of the fungus development by up to 90%, independently of any cryptogein treatment and in the absence of apparent necrosis. These results indicate that the up-regulation of apoplastic RNase activity after inoculation could contribute to the control of fungal invasion in plants induced to SAR with cryptogein.

Algal Proteins↗
PubMed1997

Granulocytic sarcomas: clinical, diagnostic and therapeutical aspects.

Granulocytic sarcomas (GS) are extramedullary tumor masses of immature myeloid cells most frequently associated with acute myeloblastic leukemia. We report our diagnostic, clinic and therapeutic approaches in the treatment of 6 patients affected by GS who presented with different localizations and symptoms: mediastinal mass with chest pain, rectal tumor with bowel occlusion, bladder mass with acute kidney failure, quadriceps tumor with pain, vertebral localization with pain and bowel mass with pain, respectively. The correct diagnosis of GS by bone biopsy, the immunohistological evaluation of the tumor masses, the prompt use of active drugs in the first line therapy schedule as for acute myeloblastic leukemia are the parameters for the achievement of the long-term remission.

Acute Disease↗
PubMed1997

[Upper digestive hemorrhage as a rare manifestation of ectopic pancreas with gastric localization].

The Authors report two cases of ectopic gastric pancreas, one of them causing a massive upper gastrointestinal hemorrhage, representing an infrequent complication of the disease. A literature review on the subject was then performed, and the importance of a differential diagnosis of the ectopy versus gastric malignancies, with relevant prognostical and management implications was assessed.

Adult↗
PubMed1996

Effect of beta-carotene and canthaxanthin on tert-butyl hydroperoxide-induced lipid peroxidation in murine normal and tumor thymocytes.

It has been reported that the anticarcinogenic effect of carotenoids could be related to an antioxidant mechanism. The antioxidant efficiency of beta-carotene and canthaxanthin was evaluated in murine normal and tumor thymocytes. Normal and tumor cells were exposed under air to tert-butyl hydroperoxide (t-BOOH) and lipid peroxidation was measured in the absence or in the presence of the two carotenoids. Our results show that: (a) Both carotenoids, added at effective and comparable concentrations (from 1 to 50 microM), were able to inhibit t-BOOH-induced malondialdehyde formation in a dose-dependent manner. (b) Canthaxanthin was a more potent antioxidant that beta-carotene. (c) The inhibition of lipid peroxidation was greater in tumor thymocytes. (d) Carotenoids were consumed differentially during the incubation with the prooxidant. beta-Carotene was consumed faster than canthaxanthin and in a larger amount in tumor than in normal thymocytes. The addition of the iron chelator deferoxamine or the SH group reducing agent dithiothreitol reduced t-BOOH-induced beta-carotene consumption in tumor cells but not in normal ones. (e) The loss of endogeneous alpha-tocopherol induced by t-BOOH was enhanced by the addition of beta-carotene, suggesting the possibility of oxidative interactions between the two antioxidants. These results confirmed the antioxidant effectiveness of carotenoids in normal and tumor cells, although differences depending on the kind of cells and carotenoids used were found.

Animals↗
PubMed1996

Localization of aspergillosis to the central nervous system among patients with acute leukemia: report of 14 cases. Gruppo Italiano Malattie Ematologiche dell'Adulto Infection Program.

We retrospectively studied a consecutive series of 100 patients with acute leukemia and aspergillosis to evaluate the clinical findings and risk factors for colonization of the central nervous system (CNS) by Aspergillus species. The diagnosis of CNS aspergillosis was made in 14 patients on the basis of the following criteria: neurological signs of CNS involvement (13 of 14 patients); cerebral CT scan findings (9 of 12); microbiological findings (6 of 12); and histological findings at autopsy (11 of 11). The majority of patients had severe neurological complications (i.e., hemiparesis or seizures), due mainly to brain abscesses or mycetomas. Autopsies were performed on 11 of 14 patients and provided evidence that CNS localization was secondary to invasive aspergillosis; in each case, the most likely primary focus of infection was the lung. Although all patients had received oral antimycotic prophylaxis and had received timely empirical antifungal treatment, they all died within a median time of 5 days from the onset of neurological symptoms. Analysis of the characteristics of patients with invasive aspergillosis did not reveal any difference between those with CNS localization and those without CNS localization.

Acute Disease↗
PubMed1996

Autologous bone marrow transplantation in late first complete remission improves outcome in acute myelogenous leukemia.

We evaluated the role of ABMT in late 1st CR AML adult patients using busulfan plus cyclophosphamide as preparative regimen. Fifty-one adult patients (mean age 36 years, range 15-59) with AML underwent ABMT in 1st CR. Three of them had a prior diagnosis of myelodysplastic syndrome; one patient had a secondary leukemia. The median interval between CR and ABMT was 8 months (range 4-20). Patients received busulfan, 4 mg/kg/day for 4 days plus cyclophosphamide 50 mg/kg/day for 4 days or 60 mg/kg/day for 2 days. No maintenance chemotherapy was administered after ABMT. Median days to reach 0.5 x 10(9)/I PMN and 20 x 10(9)/I platelets were 26 (range 12-250) and 74 (range 16-740), respectively. No transplant-related deaths were observed. Five-year actuarial overall survival rate is 76.9%; actuarial leukemia-free survival rate is 70.6%. Mean follow-up from ABMT is 35 months. Leukemia-free survival of this group was compared with that of 38 non-transplanted patients younger than 60 years, who maintained a CR longer than 8 months in the same period. This analysis shows a statistically significant difference in favor of ABMT patients. These results suggest that, even if performed late after 1st CR as post-remission intensification, ABMT can improve the outcome of AML patients.

Adolescent↗
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↗