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Biomedical subjects

A Bertuzzi

Publications and source records attributed to A Bertuzzi.

At least 37 records · Page 2Linked to original sources
PubMed1995

Cell cycle analysis by the relative movement approach: effect of variability across S-phase of DNA synthesis rate.

Cell populations pulse-labelled with BrdUrd, and sampled at increasing times after the pulse, yield DNA-BrdUrd distributions from which the relative movement (RM) and the depletion function (DF) of labelled, undivided cells can be calculated. In this paper we present an extension of the equation for the time course of RM, given by White and Meistrich (Cytometry 1986, 7, 486-490), to the case in which the rate of DNA synthesis changes across S-phase. Some modalities of cell loss were also considered. Computer simulations showed that different patterns of DNA synthesis rate across S-phase can result in appreciably different RM curves. An analytical expression of the RM curve, in which the variability across S-phase of the rate of DNA synthesis is accounted for by only one parameter, was proposed. This expression was used for the simultaneous fitting of time sequences of RM and DF data of U937 cells, in order to estimate the phase transit times TS and TG2+M, and the potential doubling time Tpot. The use of the extended model gave better results than those obtained under the assumption of constant rate of DNA synthesis across S-phase.

Bromodeoxyuridine↗
PubMed1994

Treatment of primary or metastatic pleural effusion with intracavitary cytosine arabinoside and cisplatin. A phase II study.

Thirty-three patients with microscopically verified primary or metastatic malignant pleural effusion were studied: 7 had malignant mesothelioma and 26 metastatic pleural disease. The treatment was based on biochemical and clinical studies which show a synergy between cytosine-arabinoside (Ara-C) and cisplatin. These drugs were instilled in the pleural cavity at the dose of 100 mg for Ara-C and 100 mg/m2 for cisplatin. The cavity was drained after 4 h. If it was possible, the treatment was repeated weekly for 3 times and, after a 6-week rest, it could be started again with the same schedule. The overall response rate (complete plus partial remissions) was 74%. Toxicity was mild or moderate. We conclude that the combination of Ara-C and cisplatin is well tolerated and produces a high response rate in the treatment of malignant pleural effusions.

Adult↗
PubMed1993

Breast metastasis from gastric signet ring cell carcinoma, mimicking inflammatory carcinoma. A case report.

We report a case of breast metastasis of signet ring cell gastric cancer clinically presented as a primary inflammatory carcinoma. Metastases to the breast are uncommon; review of the literature demonstrated only 300 cases. The clinical and radiographic features of the metastatic lesion were unlike those reported in the literature. Although a primary signet ring cell breast carcinoma were described, the pathologic patterns of the breast lesion, here reported, lead us to conclude this was a metastasis and not another primary tumor.

Adenocarcinoma↗
PubMed1993

Sebacic acid binding to human plasma albumin.

Sebacic (decanedioic) acid is a dicarboxylic acid proposed recently as an alternative energy substrate in total parenteral nutrition. In this paper, binding of sebacic acid to defatted human plasma albumin, also in the presence of decanoic acid, was studied by means of equilibrium dialysis. In addition, the binding of sebacic acid in human serum was investigated. Binding to defatted albumin was analysed by a model with two independent classes of sites with different affinity constants. The fitting procedure took into account some of the measurement errors that are likely to affect the equilibrium dialysis technique. We found for sebacic acid one binding site with affinity constant 3.69 x 10(4) M-1 and four to five sites with affinity constant 7.14 x 10(2) M-1. Association constants for decanoic acid are 3-4-fold larger than those of sebacic acid. Data of binding of sebacic acid in human serum suggested that only three to five of the low affinity sites are available for binding. When disodium sebacate is administered i.v. for total parenteral nutrition, a substantial fraction of sebacic anions is likely to be bound in serum.

Binding Sites↗
PubMed1993

[Adrenal myelolipoma. Historical, etiopathogenetic, pathologic, clinical, epidemiologic and radiologic features. A case report].

Adrenal myelolipoma is a rare, benign, non-functional tumor composed of fat and brown erythropoietic marrow in varying proportions. It is a rare clinical entity. Usually asymptomatic, in the majority of cases it is found incidentally at autopsy. The authors discuss the historical, etiopathogenetic, anatomo-pathological, clinical-epidemiological and radiological features. They also describe a case of myelolipoma of the right adrenal gland come to their observation.

Adrenal Gland Neoplasms↗
PubMed1992

Excimer laser ablation of a corneal protuberance.

The ablation of a post-traumatic superficial corneal nodule with an argon fluoride excimer laser is reported. Three months postoperatively the area had a smooth surface with no distortion of adjacent cornea.

Adult↗
PubMed1992

Bifocal versus monofocal intraocular lenses in bilateral pseudophakia.

After a mean follow up of 19 months, the visual characteristics of eyes with bifocal diffractive intraocular lenses (IOLs) ("bifocals") in one eye were compared with those of fellow eyes with monofocal IOLs ("monofocals") in 29 bilateral pseudophakic patients. All of the eyes had a distance-corrected acuity of 0.6 or more, but 24.1% of the bifocals and 48.3% of the monofocals had an acuity of 1.00. Near acuity with distance correction was J2 or more in 93.1% of the bifocals and in 17.4% of the monofocals (without correction: 79.3% and 41.4%, respectively). In 55.2% of the bifocals and 20.7% of the monofocals, the combined uncorrected acuity was 0.5 or more for distance and J2 or more for near. Fogging revealed a similar depth of focus in the monofocals and a similar distance focus in the bifocals. The bifocals had two peaks of acuity but no "plateau" between them. The eye with the monofocal IOL was preferred by 37.9% and the eye with the bifocal IOL by 10.3%. Vision in no eye was rated "poor." Visual disturbances were more frequent in the bifocals. No glasses were prescribed for 20.7% of all of these patients; 65.5% required bifocal glasses; 44.8% managed most of daytime without glasses.

Cataract Extraction↗
PubMed1991

Pharmacokinetic analysis of azelaic acid disodium salt. A proposed substrate for total parenteral nutrition.

Azelaic acid was the first dicarboxylic acid proposed as an alternative energy substrate in total parenteral nutrition. In this study, the pharmacokinetics of azelaic acid were investigated in 12 healthy volunteers, 7 receiving a constant infusion (10g over 90 min) and 5 a bolus dose (1g). The 24h urinary excretion and plasma concentration in blood samples taken at regular intervals were assayed by gas-liquid chromatography. Experimental data were analysed by a 2-compartment nonlinear model that describes both tubular secretion and cellular uptake in Michaelis-Menten terms. A high value of urinary excretion (mean 76.9% of infused dose) and a mean clearance of 8.42 L/h were found, suggesting the presence of tubular secretion. Estimating the population mean of the pharmacokinetic model parameters gave a maximal cellular uptake of 0.657 g/h. The model predicts that 90% of the maximal uptake should be reached in the plateau phase of a constant infusion of 2.2 g/h. The presence of extensive and rapid losses through urinary excretion, and the low estimated value of the maximal cellular uptake, indicate that azelaic acid is not suitable as an energy substrate for total parenteral nutrition.

Adult↗
PubMed1990

Study of propidium iodide binding to DNA in intact cells by flow cytometry.

We studied the in situ binding of propidium iodide to DNA in fixed human lymphocytes, using flow cytometry. Experimental data of fluorescence emission vs dye concentration and vs cell concentration were obtained. Data were interpreted by means of two different mathematical models specific for the staining reaction, and the binding parameters were obtained by "best-fitting" of the data. A model based on two classes of binding sites with different affinity constants gave the most satisfactory fitting. The accessibility of the in situ chromatin turned out to be reduced with respect to the non in situ accessibility for ethidium bromide as reported in the literature. The present study shows the usefulness of the flow-cytometric technique for probing DNA structure in intact cells.

Binding Sites↗
PubMed1988

In vitro motility of non-pregnant rat uterine horns.

The in vitro spontaneous mechanical and electrical activity of the non-pregnant rat uterine horn was investigated. An isometric isovolumic preparation was used to obtain records of intraluminal pressure, axial force, extracellular electrical activity and horn morphology. Mean intraluminal pressure was 28.6 cmH2O and mean force 2.5 g. Burst electrical activity was initiated at the ovarian end in 70% of the cases. Detailed analysis of electrical and mechanical events during a single contraction showed a preparatory phase involving the longitudinal muscle layer, followed by a stronger contractile event involving both longitudinal and circular layers. Moreover, the mechanical activity was modulated at the frequency of a component (0.16-0.20 Hz) of the slow electrical activity of the horn. Burst electrical activity appeared at five equidistant electrodes along the horn with variable delays: the highest delays (mean values 7.4 s for burst activity initiated at the ovarian end and 6.5 s at the vaginal end) were observed in the middle part of the horn. The spontaneous contraction of the segment appeared to be due to the activation of separate regions of the horn (i.e. an ovarian and a cervical region), more than to a propagated excitatory action.

Action Potentials↗
PubMed1987

Kinetic and survival response of the M14 cell line to lonidamine associated with adriamycin or hyperthermia.

Lonidamine (LND), an indazole-carboxylic acid derivative, was delivered alone and together with adriamycin (ADM) or hyperthermia to the human melanoma cell line M14, and cell survival was assessed. Cell cycle-specific effects were investigated by analyzing sequences of DNA content histograms by means of a suitable mathematical procedure. LND delivered for 1 h at a dose of 50 micrograms/ml did not affect proliferation and survival of the cells. Exposure of the cells for 1 h to ADM (1.0 microgram/ml) followed by LND for 1 h (50 micrograms/ml) produced the highest effect on the survival. Kinetic parameters were affected by the combined treatment slightly more than by ADM exposure alone. Simultaneous delivery of LND (50 micrograms/ml) with hyperthermia (42 degrees C, 1 h) reduced the survival and enhanced the block of cells in the G2M phase, as compared with the heat treatment alone. The effect of the treatments on cell survival appeared to be related to the perturbation of the G2M phase of the cycle.

Antineoplastic Agents↗
PubMed1986

Prediction of lithogenic character of human bile by a quaternary system.

The lithogenic character of human gallbladder bile was investigated by a mathematical model on the basis of a clinical data set. Each bile was described by means of the quaternary system bile salts--phospholipids--free fatty acids--cholesterol. Reporting a set of bile samples on the tetrahedron of concentrations, a clear separation emerged between the control bile, the bile from patients with gallstones, and the bile of subjects with gallbladder dyskinesia. This group was characterized by a largely increased content of free fatty acids.

Adult↗
PubMed1984

Analysis of DNA synthesis rate of cultured cells from flow cytometric data.

The rate of DNA synthesis along S phase is estimated from flow cytometric histograms on the basis of a mathematical model of a cell population. In the absence of loss, the model expresses the population kinetics in terms of DNA synthesis rate, S-phase influx, and population size. A single histogram is sufficient to determine the DNA synthesis rate when the population is in balanced exponential growth. Two suitably chosen histograms are necessary if the S-phase influx is exponential in a time interval longer than the S-phase duration. The analysis procedure was tested on published autoradiographic data and applied to three cultured cell lines (CM-S, 3LL, and M14 cells) that show various patterns of DNA distribution. In each case the cell-cycle fractions, the DNA synthesis rate, and the S-phase duration were obtained.

Animals↗
PubMed1983

A general expression for sequential DNA-fluorescence histograms.

A general expression for time sequences of DNA-fluorescence histograms from flow microfluorometry is given in this paper. Such expression is given in terms of the law of DNA growth along S phase, the flux of cells into S, and the efflux out of M. Special conditions of growth (e.g. the exponential steady-state growth), and the case of blocks in S phase are also analyzed. Some simulations of the expressions obtained are presented.

Cells, Cultured↗
PubMed1983

Estimation of cell DNA synthesis rate from flow-cytometric histograms.

The rate of DNA synthesis along S-phase can be estimated on the basis of a simple model of a cell population, from a single FCM histogram under conditions of balanced exponential growth, and from two histograms suitably spaced in time under conditions of locally exponential S-phase influx. An algorithm that constructs a piecewise constant approximation of the synthesis rate and estimates the phase fractions from a single histogram is presented. The results of the application of the algorithm to a set of computer generated histograms in balanced exponential growth are reported.

Animals↗