Biomedical subjects

A Preti

Publications and source records attributed to A Preti.

At least 55 records · Page 3Linked to original sources

PubMed1997

The influence of seasonal change on suicidal behaviour in Italy.

The seasonal variance of suicides and attempted suicides in Italy from 1974 to 1994 has been studied to determine the extent and the nature of the seasonal influence on suicidal behaviour. The relationship between some climatic factors and suicide and attempted suicide rates has also been analyzed. A significant effect of seasonal change on suicidal behavior, with a clear peak in spring has been detected (ANOVA: df = 3/248, F = 5.875, p = 0.0007 for suicide; df = 3/248, F = 6.198, p = 0.0004 for attempted suicide), with a greater seasonal effect on males than females. The monthly distribution of suicide deaths and of attempted suicides follows a significant direct relationship with exposure to sun, and an inverse relationship with rainfall levels. So, one of the possible explanations for the effect of seasonal change on suicidal behaviour could be the changing seasonal climate. The complex influence of seasonal climate on human biological rhythms, particularly on 5-HT (serotonin) related functions, together with its effects on sociorelational habits, should be considered for suicide prevention.

Climate↗

PubMed1997

Paclitaxel activity for the treatment of non-Hodgkin's lymphoma: final report of a phase II trial.

In order to determine the activity of paclitaxel in patients with relapsed or refractory non-Hodgkin's lymphoma (NHL), we conducted a phase II clinical trial in which eligible patients received paclitaxel 200 mg/m2 intravenously over 3 h. Treatment was repeated every 3 weeks. Patients achieving complete or partial responses after two courses of paclitaxel continued to receive therapy for a maximum of eight courses, otherwise they were removed from the study. Of 96 evaluable patients, 45 (47%) had primary refractory disease, and 51 (53%) had relapsed lymphoma. The median number of prior treatment regimens was two (range one to 10 regimens). 45 patients had lowgrade, 44 had intermediate-grade, and seven had mantle cell lymphoma. 24/96 patients responded (10 complete and 14 partial remissions) for an overall response rate of 25% (95% CI 17-35%). Patients with relapsed lymphoma had a higher response rate than those with primary refractory disease (19/51 = 37% v 5/45 = 11%; P < 0.01), and patients with relapsed intermediate-grade lymphoma had a higher response than those with relapsed low-grade lymphoma (9/18 = 50% v 10/31 = 32%; P = 0.22). The treatment was very well tolerated with the most common side-effects being alopecia (100%), peripheral neuropathy (35% of > or = grade II), and arthralgia/myalgia (25% of > or = grade II). After the first course of paclitaxel, grade III/IV thrombocytopenia and neutropenia were observed in 21% and 23% of the patients respectively. 23 episodes of neutropenic fever developed after 250 courses of paclitaxel therapy (8%). We conclude that paclitaxel, at this dose and schedule, is an active new drug for the treatment of non-Hodgkin's lymphoma. The activity of paclitaxel combination programmes are currently under investigation.

Adult↗

PubMed1997

Phase I study of fludarabine and paclitaxel for the treatment of low-grade non-Hodgkin's lymphoma.

We conducted a phase I clinical trial of a new combination of fludarabine and paclitaxel in which 19 patients with histologically confirmed recurrent low-grade non-Hodgkin's lymphoma (NHL) were treated at five dose levels. Fludarabine was administered intravenously by bolus for 5 days and paclitaxel was given by intravenous (I.V.) continuous infusion for 96 or 72 hours starting day 1. Courses were repeated every 4 weeks. Patients whose disease responded received a maximum of six courses. All 19 patients received at least one course and could be evaluated for toxic effects, and 18 patients could be evaluated for response. The maximum tolerated dose (MTD) was 20 mg/m2/day I.V. bolus for 5 days of fludarabine plus 60 mg/m2/day I.V. of paclitaxel given as a continuous infusion over 72 hours. The limiting toxic effect was neutropenic fever, which was observed in five of the seven patients treated at the highest dose level. Grade 3 non-hematologic toxic effects of stomatitis (14%), neuropathy (14%), and hypotension (14%) were also observed at the highest dose level. No grade 4 non-hematologic toxic effects or treatment-related deaths occurred. One patient had herpes zoster infection of the skin 1 year after the completion of therapy. The overall response rate was 50%, with the two patients whose disease completely responded remaining disease free at 22 and 17 months. Patients with no prior exposure to either paclitaxel or fludarabine had 62% response rate. We conclude that the combination of fludarabine and paclitaxel appears to have promising activity for the treatment of recurrent low-grade NHL.

Adult↗

PubMed1997

Paclitaxel (Taxol) for the treatment of lymphoma.

Paclitaxel (Taxol) was recently tested in patients with relapsed and refractory lymphoma in two phase II clinical trials using two different infusion schedules. The first, reported from the NCI (USA), used a 96-hour intravenous continuous infusion schedule, and the second, from our group, used a 3-hour infusion. In the NCI trial, 29 evaluable patients were treated with 140 mg/m2 every three weeks, which achieved a 17% response rate (all PRs); while we treated 96 evaluable patients with 200 mg/m/ every three weeks, which achieved a 25% response rate (10 CRs and 14 PRs, 95% CI: 17%-35%). In our trial, patients with relapsed (not primary refractory) intermediate-grade lymphoma had a response rate of 50%, and those with relapsed low-grade lymphoma had a response rate of 31%. In a follow-up trial, 12 patients who failed to respond to 3-hour infusion of paclitaxel were crossed over to receive paclitaxel by 96-hour infusion. None of the 12 evaluable patients achieved a major clinical response. Similarly, of 25 patients treated with cyclosporine A and paclitaxel after failing therapy with single-agent paclitaxel, only one patient (4%) responded. We conclude that paclitaxel has a promising single-agent activity, most prominently in patients with relapsed intermediate-grade lymphoma. Paclitaxel-based combination programs are currently being evaluated in our institution.

Antineoplastic Agents, Phytogenic↗

PubMed1996

Enzymatic activities affecting exogenous nicotinamide adenine dinucleotide in human skin fibroblasts.

The fate of nicotinamide adenine dinucleotide (NAD), AMP, and ADP-ribose supplied to intact human skin fibroblasts was monitored, and the concentrations of intra- and extracellular pyridine and purine compounds were determined by HPLC analysis. Two enzymatic activities affecting extracellular NAD were detected on the plasma membrane, one hydrolyzing the pyrophosphoric bond and yielding nicotinamide mononucleotide (nucleotide pyrophosphatase) and the other cleaving the glycoside link and releasing nicotinamide (NAD-glycohydrolase). No AMP or ADP-ribose was found in the extracellular medium of cells incubated with NAD, the former being completely catabolized to hypoxanthine and the latter degraded to adenine and hypoxanthine.

Adenosine Diphosphate Ribose↗

PubMed1996

Cytomegalovirus pneumonia in adult nontransplantation patients with cancer: review of 20 cases occurring from 1964 through 1990.

The objectives of this study were to estimate the frequency of cytomegalovirus (CMV) pneumonia and describe its clinical and radiological presentation in adult nontransplantation patients with cancer. Of the 10,441 autopsies performed at M. D. Anderson Cancer Center (Houston) during the period of January 1964 through December 1990, 9,029 were evaluable. Twenty histopathologically confirmed cases of CMV pneumonia were found, representing a frequency of 2.2 cases per 1,000 autopsies. When the frequency of CMV pneumonia was compared for the periods 1964-1979 (1.5 cases per 1,000 autopsies) and 1980-1990 (4.6 cases per 1,000 autopsies), a statistically significant increase due to an increase in the number of patients with solid malignancies was observed (P < .05). CMV pneumonia is an uncommon diagnosis at autopsy for adult nontransplantation patients with cancer and is usually found in conjunction with a disseminated neoplastic process.

Adult↗

PubMed1995

Purification of LamB proteins using continuous elution electrophoresis: a comparison with immunoaffinity chromatography.

LamB is a membrane protein that allows the exposition of a foreign peptide on the surface of a recombinant E. coli cells. An immunopurified hybrid LamB protein has been used to elicit high-titre antibodies to a foreign epitope. Looking for a simpler purification procedure we have compared the traditional approach, which includes affinity chromatography, to continuous elution electrophoresis, in the purification of two different hybrid LamB proteins as foreign epitopes. The results obtained showed that both methods yielded the same purification, although the electrophoretic procedure had a higher yield. Continuous-elution electrophoresis could be a useful tool for the purification of membrane proteins.

Antibodies, Monoclonal↗

PubMed1994

Sulforhodamine GM1-ganglioside: synthesis and physicochemical properties.

A fluorescent derivative of GM1-ganglioside was synthesized by linking sulforhodamine 101 to the sphingosine moiety through amino dodecanoyl residue. The product (SR-12GM1) was quantitatively converted to SR-12GM2 by treatment with bovine testes beta-galactosidase and in intact cultured human skin fibroblasts was catabolized to sulforhodamine GM2, GM3 and ceramide; the latter product was further converted to sphingomyelin. In aqueous medium SR-12GM1 formed micelles. When transfer from micelles to vesicles and between vesicles was compared with that of pyrene-GM1, the transfer of SR-12GM1 occurred at higher rates, following in both cases a biexponential curve.

Animals↗

PubMed1994

Hodgkin's disease with a mediastinal mass greater than 10 cm: results of four different treatment approaches.

BACKGROUND: Management of Hodgkin's disease (HD) and large mediastinal adenopathy (LMA) usually includes intensive chemotherapy (CT) with or without radiation therapy (XT) regardless of stage. PATIENTS AND METHODS: One hundred and eighteen evaluable patients received one of four treatment regimens: (1) 6 cycles of MOPP or similar CT and XT; (2) 2 of MOPP followed by XT; (3) 6 of CVPP/ABDIC (cyclophosphamide, vincristine, procarbazine, prednisone/doxorubicin, bleomycin, decarbazine, prednisone, lomustine) followed by XT; or (4) 3 of NOVP (mitoxantrone, vincristine, vinblastine, procarbazine) and XT. XT doses included 30-40 Gy to areas of nodal involvement noted prior to therapy. RESULTS: Complete remission (CR) rates for groups 1, 2, 3, and 4 were 100%, 85%, 87%, and 96%. Respective 3-year freedom from progression (FFP) results were 88%, 66%, 82%, and 88%, and 3-year freedom from tumor mortality (FTM) results were 100%, 84%, 84%, and 100%. The presence of B symptoms and stage IV disease was correlated with lower CR and 3-year FFP rates but similar 3-year survival. CONCLUSIONS: Results of this study suggest that patients with stage I-III Hodgkin's disease and LMA greater than 10 cm treated with 3 NOVP and XT have results similar to those obtained for a similar group of patients treated with 2 to 6 MOPP or 6 CVPP/ABDIC and XT. NOVP has also been reported to produce limited toxicity in this trial and should be considered as an alternative to MOPP or doxorubicin-containing regimens in treatment of patients with early-staged disease and LMA greater than 10 cm.

Adolescent↗

PubMed1994

Acute lymphocytic leukaemia in the elderly: characteristics and outcome with the vincristine-adriamycin-dexamethasone (VAD) regimen.

To analyse the pretreatment characteristics, response to therapy, and overall prognosis of elderly patients with acute lymphocytic leukaemia (ALL), 268 consecutive adults with newly-diagnosed ALL who received the vincristine-adriamycin-dexamethasone (VAD) regimens were reviewed. Pretreatment characteristics, response to VAD therapy, and overall outcome were analysed in patients 60 years or older, and compared to younger patients. Fifty-two patients (19%) were 60 years or older. Compared with younger patients, elderly patients with ALL had a significantly worse performance status at presentation (P < 0.001); higher incidences of FAB L2 morphology (P = 0.03), thrombocytopenia (P < 0.01), hypoalbuminaemia (P < 0.001) and renal dysfunction (P = 0.03); and trends for worse anaemia (P = 0.06) and a higher rate of myeloid markers positivity (P = 0.06). With VAD induction therapy, elderly patients had a lower CR rate than younger patients following two induction courses (CR rate 58% v 82%; P < 0.01), and overall (CR rates 65% v 90%; P < 0.01). The response rate to VAD chemotherapy, however, appeared superior to the 30-35% CR rates reported from other series in elderly ALL patients. The lower CR rate was due to both higher induction mortality (P = 0.02) and more resistant disease (P < 0.01). The long-term CR rate was 20% in elderly patients achieving CR, but the overall survival was poor (< 10% at 3 years). There were strong associations between older age and other poor prognostic features. However, multivariate analyses identified older age to be an independent poor prognostic factor for response to chemotherapy. In summary, elderly patients with ALL have an appreciable CR rate with the VAD regimens. Patients achieving CR may have durable remissions. The myelosuppression-associated mortality in both remission induction and maintenance may be reduced with the addition of growth factors in both treatment phases, and by using standard maintenance therapy without consolidation-intensification phases.

Age Factors↗

PubMed1994

Imipramine in alopecia areata. A double-blind, placebo-controlled study.

Alopecia areata (AA) is a dermatologic disease whose onset is significantly associated to life events. Its course may often be characterized by high levels of anxiety and depression. These observations suggested a rationale for using an antidepressant in AA. Thirteen patients were enrolled in a double-blind, placebo-controlled study of efficacy of imipramine in alopecia. After six months clinically significant hair regrowth occurred in 5 of the 7 patients on imipramine, whereas no response was observed in the placebo group. An improvement in psychic symptomatology was present in both groups. Our preliminary results indicate the potential efficacy of imipramine in patients with AA, not acting directly through a reduction of anxiety or depression.

Adult↗

PubMed1994

Management of adult acute lymphocytic leukemia: present issues and key challenges.

PURPOSE: To discuss the controversies in current adult acute lymphocytic leukemia (ALL) management in relation to its different phases of therapy. DESIGN: A review of treatments in adult ALL from the English literature. RESULTS: Features signaling high risk for systemic relapse (older age, high WBC count at diagnosis, non-T-cell immunophenotype, Philadelphia chromosome (Ph)-positive karyotype, and longer time to achieve remission) are found in 60% to 70% of patients with adult ALL. These patients have a potential cure rate of 20% to 25%, compared with 60% to 70% for low-risk patients. Induction regimens with vincristine, anthracyclines, and corticosteroids appear to be optimal. Intensification-consolidation therapy increased cure rates modestly in adult ALL; higher-dose schedules of mercaptopurine (6-MP), methotrexate, and asparaginase may be beneficial. Maintenance therapy with 6-MP and methotrexate is suggested based on the worse outcome of patients in whom such maintenance was omitted. Allogeneic bone marrow transplantation (BMT) is indicated for patients in first remission with high-risk for relapse; autologous BMT for patients in first remission remains investigational. Patients with mature B-cell ALL require short-term, dose-intensive therapy that alternates hyperfractionated doses of cyclophosphamide with high-dose cytarabine (ara-C) and methotrexate. Patients with T-cell ALL may benefit from ara-C/cyclophosphamide combinations during maintenance therapy. CNS prophylaxis with intrathecal chemotherapy should be administered in patients at risk for CNS relapse. CONCLUSION: Potential strategies to improve the prognosis of high-risk patients with ALL include increasing the dose-intensity of remission induction and consolidation-intensification therapies with growth factor support; discovering and using new anti-ALL drugs; improving autologous BMT results; translating biologic studies of leukemia cell characteristics, karyotype-related molecular aberrations, abnormal oncogenic expression, and minimal residual disease into clinically relevant therapies; and using investigational treatment strategies in high-risk patients.

Adult↗

PubMed1994

Characteristics and outcome of patients with acute lymphocytic leukemia and myeloperoxidase-positive blasts by electron microscopy.

The purpose of the study was to analyze the clinical and laboratory characteristics of patients with acute lymphocytic leukemia (ALL) who exhibited myeloperoxidase-positive blasts by electron microscopy (EM-MPO-positive), and assess their response to therapy and their prognosis. Since 1988, 21 adults with newly-diagnosed ALL and EM-MPO-positive blasts were referred to our service. In addition to documentation of their clinical and hematopathologic characteristics, patients underwent cytogenetic, immunophenotypic, molecular, and electron-microscopic evaluations. Twenty patients were treated with the vincristine-Adriamycin-dexamethasone (VAD) regimen, and one patient was induced with amsacrine and high-dose cytosine arabinoside (ara-C). The 21 patients were among 141 patients with ALL (15%) seen during the same period. Their median age was 46 years (range 15 to 77 years). The immunophenotype was T-cell ALL in 12 patients (57%). Karyotypic studies did not demonstrate specific recurrent abnormalities. The median percentage of EM-MPO-positive blasts was 15% (range 3% to 45%). Eighteen patients (85%) had high-risk ALL. With induction chemotherapy 15 of 20 (75%) receiving VAD therapy achieved a complete remission (CR). However, the median CR duration was 18 months, and the median survival was 18 months with a 3-year disease-free survival rate of 25%. There were eight relapses and one lineage switch to acute myelogenous leukemia (AML). Patients with ALL and EM-MPO-positive disease are a unique subgroup with long-term poor prognosis on conventional anti-ALL therapy, and may benefit from intensification treatments with agents effective against AML.

Adolescent↗

PubMed1993

High-titre antibodies to a foreign epitope elicited by affinity-purified hybrid LamB proteins.

A monoclonal antibody to the LamB protein, named LBS-1, was developed and characterized. It was then covalently bound to Sepharose and used to purify hybrid LamB proteins from Escherichia coli crude extracts. A peptide of the interferon-gamma (IFN-gamma) NH2-terminal region, inserted within the LamB protein, was used as a model to assess immune response in mice injected with sonicated E. coli extract or with affinity-purified hybrid LamB protein. None of the mice immunized with the whole bacterial extract produced antibodies to IFN-gamma. On the other hand, all the mice immunized with the purified protein developed high-titre anti-IFN-gamma antibodies. These results might be due to the presence of bacterial components capable of masking the LamB protein to the immune system. The use of affinity-purified LamB proteins may constitute in some instances a more effective way of generating an immune response against foreign epitopes as opposed to whole bacterial antigens.

Amino Acid Sequence↗

PubMed1992

Cultured oligodendrocytes metabolize a fluorescent analogue of sulphatide; inhibition by monensin.

It has been suggested that oligodendrocytes can actively phagocytose myelin debris during active myelination or after injury and experimental demyelination. Therefore, we have used a fluorescent analogue (N-lissamine rhodaminyl-(12-aminododecanoyl) cerebroside 3-sulphate) to study the metabolic fate of sulphatide, a galactosphingolipid that is highly enriched in myelin membranes. The fluorescent sulphatide was incorporated in small unilamellar vesicles and administered to cultured oligodendrocytes. The association of the lipid probe to the cells in culture was saturable in time and with the concentration of the probe. The processes of association, internalization and subcellular distribution were followed by confocal scanning laser microscopy and appeared to be very rapid. Within 20 min a marked perinuclear staining was seen. After prolonged incubation the fluorescence distributed gradually over the cytoplasm and into cellular branches along structures suggestive of cytoskeletal elements. Lipid analysis demonstrated that ceramide was the major metabolite present in the cells but galactosylceramide, sphingomyelin and free fatty acid were also detected. In the culture medium only free fatty acid and sphingomyelin were found. Monensin did not affect the cellular association and internalization of the fluorescent sulphatide but markedly reduced its conversion to metabolic products. These results indicate that exogenous sulphatide is targeted to the Golgi apparatus prior to its lysosomal degradation.

Animals↗

PubMed1992

Uptake and metabolism of a fluorescent sulfatide analogue in cultured skin fibroblasts.

The sulfatide fluorescent analogue N-lissamine rhodaminyl-(12-aminododecanoyl) cerebroside 3-sulfate was administered in the form of albumin complex to normal human skin fibroblasts and its metabolic fate was investigated. Ceramide, galactosylceramide, glucosylceramide, sphingomyelin and free acid, all containing the fluorophore lissamine rhodamine, have been synthesized as reference standards for the identification of the metabolic products. Ceramide appeared to be the main metabolic product present both in cell extract and medium, followed by galactosylceramide and sphingomyelin. Fluorescence microscopy of cells showed a marked perinuclear fluorescence.

Adolescent↗

PubMed1990

Synthesis, spectral properties and enzymatic hydrolysis of fluorescent derivatives of cerebroside sulfate containing long-wavelength-emission probes.

Fluorescent derivatives of cerebroside sulfate (sulfogalactosyl ceramide, sulfatide) containing long-wavelength-emission fluorophores were synthesized. For this purpose a procedure was developed for preparing a cerebroside 3-sulfate derivative with an amino group on the terminal carbon atom of its fatty acyl residue. The latter compound has been used to prepare cerebroside 3-sulfate, coupled to lissamine-rhodamine, fluoresceine, eosine and NBD. The spectroscopic properties of these compounds, in different solvent systems and when incorporated into micelles of a non-ionic detergent or liposomes of a phospholipid, are reported. Incubation of these respective sulfatides with a human leukocyte preparation, resulted in the formation of the corresponding fluorescent cerebrosides.

Cerebroside-Sulfatase↗

PubMed1989

Rapid preparation of a distinct lysosomal population from myelinating mouse brain using Percoll gradients.

To study the vesicular lysosome-associated transport and the metabolism of some brain macromolecules (in particular, sialoglycoconjugates), we developed a rapid procedure to obtain a distinct lysosomal population starting from myelinating mouse brain. This procedure is based on an initial differential centrifugation step producing a 1,000-17,500-g fraction (P2), followed by isopycnic centrifugation of fraction P2 on a self-generated colloidal silica gel (Percoll) gradient. The heaviest subfraction thus obtained is very rich in acid hydrolase activities like beta-galactosidase, arylsulfatase A, and acid phosphatase. The enrichment of these enzymes is approximately 100-fold as compared with the starting homogenate, whereas the markers of other subcellular organelles, such as mitochondria, plasma membranes, or the Golgi apparatus, are virtually absent. The lysosomal preparation contains approximately 12-14% of the total acid hydrolase activities, with a protein yield of approximately 0.12%. Electron microscopy shows that the lysosomal fraction is composed of an approximately 90% pure population of lysosomes. Therefore, the procedure described here is suitable for obtaining a highly purified lysosome preparation from myelinating mouse brain.

Animals↗