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Biomedical subjects

A Bertuzzi

Publications and source records attributed to A Bertuzzi.

At least 19 recordsLinked to original sources
PubMed2002

Reduced intensity conditioning regimen followed by glycosylated G-CSF mobilized PBSCT in patients with solid tumors and malignant lymphomas.

The aim of this pilot study was to exploit the graft-versus-tumor potential of allogeneic transplants while improving safety of the procedure. Twelve patients with advanced hematological malignancies and solid tumors underwent a low intensity conditioning regimen (fludarabine and cyclophosphamide) followed by an allogeneic peripheral blood stem cell transplantation. The median time to achieve an absolute neutrophil count of more than 0.5 x 10(9)/l and an untransfused platelet count of more than 20 x 10(9)/l was 15 and 14 days, respectively. The main extra-hematological toxicities were mucositis and infections. Acute graft-versus-host (GVHD) disease was experienced by 62% of evaluable patients (grade II/B or III/C 80%) responsive to steroids. Extensive chronic GVHD was observed in 62% of patients. Non-relapse transplant-related mortality by day +30 was observed in three patients (25%). Eight out of 12 patients were full donor chimeric by day +100. One patient showed a mixed chimerism at day +37 when he died from progressive disease. One patient was in complete remission (CR) before allogeneic transplantation, and after transplantation four patients achieved CR and four experienced progressive disease. Our study confirms that a low intensity conditioning regimen for allogeneic stem cell transplantation is feasible and effective in heavily pretreated patients.

Adult↗
PubMed2002

Intensified CHOP regimen in aggressive lymphomas: maximal dose intensity and dose density of doxorubicin and cyclophosphamide.

BACKGROUND: Following our previous study of CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) intensification in non-Hodgkin's lymphoma (NHL), in the present report we attempted to further increase dose intensity by shortening the between-course intervals with the support of growth factors. PATIENTS AND METHODS: A total of 67 patients were enrolled. With a fixed dose of doxorubicin 75 mg/m(2), cyclophosphamide (CTX) was started at a dose of 1750 mg/m(2) and increased by 250 mg/m(2) in consecutive cohorts of patients provided that no dose-limiting toxicity occurred. After the maximal tolerated dose (MTD) had been identified, this was used to treat more patients in order to confirm the feasibility of the regimen on a large scale, with the number of cycles being varied on the basis of disease extension. RESULTS: Twenty-three cases were enrolled in the CTX dose finding phase. Dose-limiting non-hematological toxicity occurred at 2250 mg/m(2). As the intermediate level of 2000 mg/m(2) had a borderline toxicity profile, a CTX dose of 1750 mg/m(2) was defined as the MTD. A total of 53 patients then received the MTD during the course of the study as a whole. At the MTD, toxicity was acceptable. Only 10 of 189 cycles (4%) required hospitalization due to infection or febrile neutropenia. Seventy-four percent of the patients achieved complete remission. Freedom from progression and overall survival at 12 months were 71% and 86% in the whole series, and 58% and 71% for high-risk cases, respectively. CONCLUSIONS: This intensified CHOP regimen is feasible on an outpatient basis. It can be safely considered a definitive treatment in patients at low and intermediate risk, and as induction before high-dose consolidation in high-risk cases.

Adult↗
PubMed2002

New bioimpedance model accurately predicts lower limb muscle volume: validation by magnetic resonance imaging.

Conventional bioimpedance analysis (BIA) methods now simplify the representation of lower limb geometry and electrical properties for body composition estimation. In the present study, a three-dimensional model of the lower limb was assembled by segmentation of magnetic resonance cross-sectional images (MRI) for adipose tissue, skeletal muscle, and bone. An electrical network was then associated with this model. BIA and MRI measurements were made in six lean subjects (3 men and 3 women, age 32.2 +/- 6.9 yr). Assuming 0.85 S/m for the longitudinal conductivity of the muscle, the model predicted in the examined subjects an impedance profile that conformed well to the BIA impedance profile; predicted and measured resistances were similar (261.3 +/- 7.7 vs. 249 +/- 9 Omega; P = not significant). The resistance profile provided, through a simpler model, muscle area estimates along the lower limb and total leg muscle volume (mean 4,534 cm(3) for men and 4,071 cm(3) for women) with a mean of the absolute value of relative error with respect to MRI of 6.2 +/- 3.9. The new approach suggests that BIA can reasonably estimate the distribution and volume of muscles in the lower extremities of lean subjects.

Adipose Tissue↗
PubMed2001

Clinical and pharmacologic study of the epirubicin and paclitaxel combination in women with metastatic breast cancer.

PURPOSE: A pharmacokinetic interaction may cause increased cardiotoxicity of paclitaxel (PTX) and high cumulative dose of doxorubicin. We tested antitumor activity, tolerability, and pharmacokinetics of the lesser cardiotoxic epirubicin (EPI) and PTX (ET combination). PATIENTS AND METHODS: Twenty-seven women with untreated metastatic breast cancer, median age of 56 years, and prominent visceral involvement (74%) were studied. Three-weekly EPI (90 mg/m(2)) and PTX (200 mg/m(2) over 3 hours) were given for a maximum nine cycles. EPI was administered 24 hours before PTX (E --> T) in cycle 1, and 15 minutes before PTX (ET) thereafter. EPI, epirubicinol (EOL), EPI-glucuronide (EPI-glu), EOL-glucuronide (EOL-glu), PTX, and 6alpha-OH-PTX were measured in plasma and urine in 14 women. RESULTS: Patients received 205 cycles of ET and a median EPI dose of 720 mg/m(2). Grade 4 neutropenia (49% of cycles) was the most frequent toxicity. Cardiac contractility was decreased in five patients. Mild congestive heart failure occurred in two (7.4%). Response rate was 76% (28% complete). Median overall survival was 29 months. On the basis of intrapatient comparison in the first 24 hours of E --> T and ET cycles, PTX did not affect EPI disposition, but significantly increased plasma exposure to EOL (by 137%), EPI-glu (threefold) and EOL-glu (twofold). Urinary excretion of EPI dose went from 8.2% in E --> T to 11.8% in ET cycles. Clearance of PTX was 30% slower in ET than E --> T. ET cycles caused lower neutrophil nadir than E --> T (644 +/- 327 v 195 +/- 91, P <.05) CONCLUSION: ET is feasible, devoid of excessive cardiac toxicity, and active. A reciprocal pharmacokinetic interference between the two drugs has pharmacodynamic consequences, and suggests a direct effect of PTX on EPI metabolism requiring ad hoc investigation.

Adult↗
PubMed2001

Mobilizing potential of ifosfamide/vinorelbine-based chemotherapy in pretreated malignant lymphoma.

The mobilizing potential and therapeutic activity of ifosfamide/vinorelbine-containing regimens with G-CSF support were explored in patients with pretreated malignant lymphomas. Ten patients with non-Hodgkin's lymphoma (NHL) received ifosfamide and vinorelbine, and 17 with Hodgkin's disease (HD) received ifosfamide, vinorelbine and gemcitabine (IGEV regimen), as induction chemotherapy before high-dose chemotherapy (HDT) with peripheral blood stem cell (PBSC) support. Most of the patients had been heavily pretreated with various chemotherapy regimens +/- radiotherapy. The target yield was > or =3 x 10(6) CD34+ cells/kg of body weight in order to support the subsequent myeloablative chemotherapy. The optimal PBSC harvest occurred on days 11 and 12, with no difference in CD34+ cell mobilization kinetics between the ifos- famide/vinorelbine and IGEV regimens. The median number of CD34+ cells/kg body weight collected was 10.9 x 10(6) (range 1.76-61.1 x 10(6)). The median total CD34+ cell/microl, CFU-GM and white blood cells (WBC) for all individual collections was 81.5/microl, 10 x 10(4)/kg, and 17 900/microl, respectively. The target yield of CD34+ cells was reached in 24 of 27 patients. Hematological side-effects were acceptable and no treatment-related hospitalizations or toxic deaths occurred. Fifteen patients have so far received high-dose therapy and PBSC reinfusion with rapid engraftment. These results confirm that ifosfamide and vinorelbine-based chemotherapy regimen with G-CSF support can be successfully and safely used to mobilize PBSCs.

Adult↗
PubMed2001

Allogeneic peripheral blood stem cell transplantation with reduced intensity conditioning in primary refractory prolymphocytic leukemia: graft-versus-leukemia effect without graft-versus-host disease.

A patient with progressive prolymphocytic leukemia (PLL) received an allogeneic stem cell transplant using a reduced intensity conditioning regimen to avoid prohibitive toxicities. Early in the post-transplant period, a high donor-derived CD8+ count was observed. One year from transplantation, the patient was in complete remission, fully donor chimeric and with a normal performance status, suggesting that this approach may represent a useful treatment option in patients with refractory PLL.

Female↗
PubMed2001

Unreliable use of standard muscle hydration value in obesity.

Intramuscular water content is assumed to be constant in humans independent of their anthropometric characteristics. To verify whether this assumption is correct, intramuscular water, proteins, glycogen, and both total and intramyocytic triglycerides were measured in 51 samples of rectus abdominis muscle obtained from 16 lean and 35 overweight and obese subjects (body mass index cutoff 24.9 kg/m2). Data (referred to as wet tissue) were analyzed by means of a composition model at the cellular level of the skeletal muscle (SM). The average SM water content was 76.3 +/- 3.3% in normal-weight individuals and 65.7 +/- 5.8% in obese subjects (P < 0.0001). Total triglycerides were 5.5 +/- 2.3% in controls and 19.0 +/- 7.0% in obese subjects (P < 0.0001). The intramyocytic triglyceride fraction was also increased in obese subjects. The composition model provides an explanation for the negative correlation between total triglycerides and intramuscular water, and some of the model parameters were determined from the experimental data. In conclusion, although the hydration of fat-free SM mass may be unchanged in obese subjects, the hydration of in toto muscle mass decreases as its lipid content increases.

Adult↗
PubMed2000

Cell kinetics in a tumour cord.

In some tumours, the viable cells grow around blood vessels forming cylindrical structures called tumour cords, which are surrounded by regions of necrosis. In the present paper, we propose a mathematical model for the cell kinetics in a tumour cord at the stationary state. Both proliferating cells and quiescent cells are considered, and the proliferating cell population is structured by age. Cell migration towards cord periphery is accounted for from a continuum viewpoint. The age distribution of proliferating cells, the fraction of cells in S phase, the growth fraction and the velocity along the cord radius are computed. The predictions of the model are compared with literature data obtained from two experimental rat hepatomas. The model was used to compute the profile of the oxygen tension within the cord. Possible modifications and extensions are also presented.

Animals↗
PubMed2000

Disposition of dodecanedioic acid in humans.

The disposition of dodecanedioic acid (C12) was investigated in six overnight-fasting healthy male volunteers, who received a 165-min i. v. infusion of 42.45 mmol of C12 added to 150 microCi of [1-12-(14)C]C12. Blood samples were collected up to 360 min after the start of infusion, and concentration of serum labeled C12 was determined. Expired radioactivity (microCi/min) was measured up to 600 min and at 24 h. The 24-h C12 urinary excretion was around 5% of the administered amount. The percentage of C12 oxidized was 81.7 +/- 9.5% (mean +/- S.D.) of administered amount as estimated from the area under the curve of measured (14)CO(2) expiration rate. C12 kinetics was described by assuming a single compartment. A saturable rate of C12 tissue uptake (model A) and a linear rate of tissue uptake (model B) were considered. The kinetics of CO(2) produced by C12 oxidation was described by a fast pathway acting in parallel to a slow pathway modeled by first order kinetics. Parameters of model B were estimated for each subject, whereas model A was identified by fitting the pooled data of all subjects. On the basis of estimates obtained from model B, an average calorie delivery of 500 kcal/day was predicted in the plateau phase for the infusion rate of our experiments. When estimated from model A, the maximal rate of tissue uptake was 0.38 +/- 0.08 mmol/min, with a maximal calorie delivery of 750 kcal/day. These results appear promising for C12 utilization in parenteral nutrition, because C12 elimination with urine is low, whereas tissue uptake and oxidation are rather efficient.

Adult↗
PubMed2000

Subclinical hepatic encephalopathy: role of tryptophan binding to albumin and the competition with indole-3-acetic acid.

BACKGROUND: The role of tryptophan (TRY) and its metabolites in the pathogenesis of hepatic encephalopathy is conflicting. The aim of the present study is to investigate in posthepatitis cirrhotic patients with encephalopathy the serum levels of TRY and those of its metabolite indole-3-acetic acid, as well as TRY binding curve to serum albumin and the competition with indole-3-acetic acid. The presence of a relationship between encephalopathy severity and circulating free TRY was also investigated. METHODS: Serum TRY and indole-3-acetic acid were analyzed by HPLC; binding of TRY to serum albumin and the competition with indole-3-acetic acid was studied by equilibrium dialysis. RESULTS: Serum-free TRY was significantly higher in cirrhotic patients (43.33 +/- 14.70 vs 28.87 +/- 8.77 mumol/L, P = 0.02). The binding capacity of albumin was reduced in cirrhotics and further decreased by the addition of indole-3-acetic (K = 6.63 +/- 0.97 x 10(3) mol/L-1, gamma = 1.16 +/- 0.45 x 10(2) mol/L-1 in normal sera vs K = 1.04 +/- 0.20 x 10(3) mol/L-1, gamma = 1.91 +/- 0.92 10(2) mol/L-1 in cirrhotic sera). A multivariate analysis showed that among the psychometric tests the only independent predictor of serum levels of free TRY was the Block Design (R2 = 0.94, B = 0.16 +/- 0.01, beta = 0.97; P < 0.0001). CONCLUSIONS: A high percent ratio of free/total TRY and indoleacetic acid (IAA) was found in cirrhotic patients with hepatic encephalopathy. The concentrations of serum-free IAA and TRY correlated with the degree of subclinical encephalopathy, suggesting a role of these compounds in the development of mental derangement in liver cirrhosis.

Adult↗
PubMed1997

Binding of indole-3-acetic acid to human serum albumin and competition with L-tryptophan.

Indole-3-acetic acid (IAA) is a product of tryptophan (Trp) metabolism and is found to be markedly increased in uremic sera. IAA binding to defatted human serum albumin at 37 degrees C and pH 5, 7.4, and 8.5 was studied by equilibrium dialysis, and data were analyzed assuming two independent high affinity binding sites plus a class of low affinity sites. The estimated values of the association constant of dominant site were: 7.96 x 10(3) M-1 at pH 5, 11.57 x 10(3) M-1 at pH 7.4, and 6.30 x 10(3) M-1 at pH 8.5. The competition between IAA and Trp for albumin binding at pH 7.4 was investigated. The results suggest that one specific albumin site is common for IAA and Trp, but the data were not adequately predicted by a purely competitive scheme. A better prediction was achieved assuming that the binding of IAA to a site different from the common site inhibits Trp binding.

Binding Sites↗
PubMed1997

Cell loss and the concept of potential doubling time.

The in vivo infusion of Bromodeoxyuridine (BrdUrd), followed by delayed biopsy and bivariate DNA-BrdUrd flow cytometry, allows the potential doubling time (Tpot) of human tumors to be estimated. According to Steel, the mathematical definition of Tpot is Tpot = ln 2/Kp, where Kp is the rate constant of cell production. All the operative formulas which allow the estimation of Tpot from flow cytometric data derive from this definition. Most authors, however, identify the potential doubling time as the doubling time that the same cell population would exhibit if cell loss were removed. We denote here as T(d)noloss this quantity. Although these two definitions are equivalent in the case of uniform random cell loss, we show, in the framework of Steel's theory of growing cell populations, that Tpot and T(d)noloss become distinct kinetic quantities when cell loss is not uniform, i.e., when loss differently affects the quiescent and the proliferative compartment. We discuss the validity of the two formulas currently used for the calculation of Tpot, one based on LI and the other on the v-function, in conditions of non-uniform cell loss. Moreover, we propose two formulas for the estimation of the cycle time T(C), which require, in addition to T(S) and LI, that a measure of the growth fraction be available.

Antimetabolites, Antineoplastic↗
PubMed1997

Steel's potential doubling time and its estimation in cell populations affected by nonuniform cell loss.

The in vivo infusion of the thymidine analogue bromodeoxyuridine (BrdUrd). followed by delayed biopsy and bivariate DNA-BrdUrd flow cytometry, makes it possible to estimate Steel's potential doubling time (Tpot) of human tumors. In the present paper, the expression of Steel's Tpot for a rather general cell population model, in which the distribution of cell loss is assumed to be nonuniform, is derived in terms of the model parameters. We show that Steel's Tpot of a population can be markedly different for the doubling time that would be exhibited by the population in the absence of cell loss. These doubling times, on the contrary, are equal when loss is uniform. Moreover, we studied the influence of modes of cell loss different from the uniform random loss on the estimation of Tpot by using the labeling index or the nu-function, quantities that can be determined from the bivariate DNA-BrdUrd distribution.

Bromodeoxyuridine↗
PubMed1997

Serum uremic toxins from patients with chronic renal failure displace the binding of L-tryptophan to human serum albumin.

The level of free tryptophan (Trp) and its metabolites in serum appears to be related to some pathologic states, such as chronic renal failure and neuropsychiatric disorders, so that a precise characterization of tryptophan binding to serum albumin is of interest. In the present paper, the binding of L-tryptophan to defatted human serum albumin at 37 degrees C and at pH 7.4 was studied by means of equilibrium dialysis. The competition between L-tryptophan and serum solutes extracted from uremic patients undergoing hemodialysis, before dialysis treatment, was also investigated. Solutes were extracted from uremic pools of sera using two different deproteinization methods: serum ultrafiltration and heat denaturation of serum proteins followed by ultrafiltration. We found 1.10 +/- 0.03 binding sites for Trp to defatted albumin with an association constant 11.37 +/- 1.03 x 10(3) M-1. The competition experiments suggested that the number of Trp binding sites were not significantly modified by the addition of solutes obtained with the method of ultrafiltration with respect to the binding of L-tryptophan to albumin in the absence of competitors, while their affinity constant was markedly reduced (2.66 +/- 0.18 x 10(3) M-1). Moreover, a significant reduction of the affinity constant was observed when competitors for Trp were obtained using heat deproteinization associated with ultrafiltration (1.91 +/- 0.15 x 10(3) M-1 vs. 2.66 +/- 0.18 x 10(3) M-1; P < 0.005). These results might be ascribed to the fact that the last procedure has a higher yield with a more complete liberation of uremic toxins from serum proteins, so that they became probably totally free thus competing at higher extent with L-tryptophan for albumin binding sites.

Binding Sites↗
PubMed1997

Kinetics of dodecanedioic acid and effect of its administration on glucose kinetics in rats.

Dodecanedioic acid (C12), a saturated aliphatic dicarboxylic acid with twelve C atoms, was given as an intraperitoneal bolus to male Wistar rats, with the aim of evaluating C12 suitability as an energy substrate for parenteral nutrition. The 24 h urinary excretion of C12 was 3.9% of the administered dose. C12 kinetics were investigated by a one-compartment model with saturable tissue uptake and reversible binding to plasma albumin. The analysis of plasma concentration and urinary excretion data from different animals yielded the population means of the kinetic parameters: renal clearance was 0.72 ml/min per kg body weight (BW) (much smaller than inulin clearance in the rat), and maximal tissue uptake was 17.8 mumol/min per kg BW corresponding to 123.7 J/min per kg BW. These results encourage the consideration of C12 as a possible substrate for parenteral nutrition. To investigate the effect of C12 administration on glucose kinetics, two other groups of rats, one treated with an intraperitoneal bolus of C12 and the other with saline, were subsequently given an intravenous injection of D[-U-14C]glucose in a tracer amount. Radioactivity data of both control and C12-treated rats were analysed by means of a two-compartment kinetic model which takes into account glucose recycling. The estimates of glucose pool size (2.3 mmol/kg BW) and total-body rate of disappearance (82.1 mumol/min per kg BW) in control rats agreed with published values. In C12-treated rats, the rate of disappearance appeared to be reduced to 36.7 mumol/min per kg BW and the extent of recycling appeared to be negligible.

Animal Nutritional Physiological Phenomena↗
PubMed1997

Prognostic factors for survival in metastatic renal cell carcinoma: retrospective analysis from 109 consecutive patients.

OBJECTIVE: Metastatic renal cell cancer (RCC) portends a bad prognosis, but survival is quite different among different patients. The objective of this study was to determine prognostic factors for survival with the aim to offer patients proper therapeutic options. METHODS: A consecutive series of 109 metastatic RCC patients admitted to our department since 1988 was reviewed, and survival from the time of diagnosis with metastases recognition was considered. The role of age, sex, disease-free interval (DFI), ECOG performance status (PS), stage at diagnosis, grading, number and type of metastatic sites, nephrectomy, blood levels of hemoglobin, creatinine, albumin, calcium, lactate dehydrogenase (LDH), ferritin, alkaline phosphatase, triglycerides was assessed in univariate and multivariate analysis. RESULTS: In our study, the following variables were found to be statistically significant at the univariate analysis (p < 0.01): DFI, ECOG PS, stage at diagnosis, grading, nephrectomy, sites of metastases, blood hemoglobin, serum albumin, calcium, LDH, alkaline phosphatase. Indeed, only an ECOG PS of 2-3 (relative risk 1.82; p = 0.003) and blood hemoglobin levels < or = 10 g/100 ml (relative risk 1.20; p = 0.017) retained their value as independent risk factors for poor survival at multivariate analysis. According to the number of independent risk factors, three groups of patients were identified, with significantly different median survival (21.7 vs. 8.6 vs. 3.5 months; log-rank test: p = 0.00004, p = 0.04126 and p = 0.00047, respectively). CONCLUSIONS: Poor performance status and anemia at diagnosis of metastatic RCC predict the worst outcome in our series. These factors could be taken into account to stratify patients in clinical trails and to select the proper treatment option in oncological practice.

Adult↗
PubMed1997

Pilot study of primary chemotherapy with doxorubicin plus paclitaxel in women with locally advanced or operable breast cancer.

A pilot study of primary chemotherapy with bolus doxorubicin plus paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) infused over 3 hours was performed in 38 women with locally advanced and 41 with stage II/III breast cancer. Patients received four cycles of primary chemotherapy followed by surgery and treatment with cyclophosphamide/methotrexate/5-fluorouracil for six cycles. Preliminary data are available on 73 patients. Doxorubicin plus paclitaxel was well tolerated. Primary toxicity consisted of grade 1 or 2 reversible peripheral neuropathy and grade 3 alopecia. After a median follow-up of 13 months, none of the patients have developed cardiac toxicity or any significant alteration of the left ventricular ejection fraction, which was measured before treatment, at each cycle of doxorubicin plus paclitaxel, and every 3 months thereafter. Major clinical response of the breast tumor was observed in 88% of patients. At pathologic examination of the surgical specimen, 40% were pT1, 15% had no macroscopic tumor residue, and 7% had complete disappearance of invasive neoplastic cells. After a median follow-up of 17 months for patients with locally advanced breast cancer, freedom from progression was 67%, disease-free survival was 71%, and overall survival was 74%. The same end points were 100% for patients with stage II/III disease, with a shorter median follow-up of 10 months. In conclusion, doxorubicin plus paclitaxel is safe, feasible, and effective, and can be used as primary or adjuvant chemotherapy to assess its actual therapeutic role in women with early breast cancer.

Adult↗