Biomedical subjects

F Caserta

Publications and source records attributed to F Caserta.

11 recordsLinked to original sources

PubMed2001

Fat depot origin affects fatty acid handling in cultured rat and human preadipocytes.

Regional differences in free fatty acid (FFA) handling contribute to diseases associated with particular fat distributions. As cultured rat preadipocytes became differentiated, FFA transfer into preadipocytes increased and was more rapid in single perirenal than in epididymal cells matched for lipid content. Uptake by human omental preadipocytes was greater than uptake by abdominal subcutaneous preadipocytes. Adipose-specific fatty acid binding protein (aP2) and keratinocyte lipid binding protein abundance was higher in differentiated rat perirenal than in epididymal preadipocytes. This interdepot difference in preadipocyte aP2 expression was reflected in fat tissue in older animals. Carnitine palmitoyltransferase 1 activity increased during differentiation and was higher in perirenal than in epididymal preadipocytes, particularly the muscle isoform. Long-chain acyl-CoA levels were higher in perirenal than in epididymal preadipocytes and isolated fat cells. These data are consistent with interdepot differences in fatty acid flux ensuing from differences in fatty acid binding proteins and enzymes of fat metabolism. Heterogeneity among depots results, in part, from distinct intrinsic characteristics of adipose cells. Different depots are effectively separate miniorgans.

Acyl Coenzyme A↗

PubMed2000

Blood viscosity and aging.

The objective of this study was to evaluate the relationship of whole blood viscosity and its major determinants (plasma fibrinogen level, hematocrit, hemoglobin and blood cell count) to advancing age. A total of 249 subjects (mean age 49.9+/-21.5; range 19-102 years) were included in the study. They were divided into three groups, (A) <30 years of age, n, 58; (B) 30-60 years, n, 107; (C) >60 years, n, 84. Whole blood viscosity at two different rates of shear (450 and 45 s(-1)) was evaluated using a cone-plate digital viscosimeter. The hematological parameters (hematocrit, hemoglobin and blood cell count) were evaluated using an automatic Coulter Counter. Plasma fibrinogen concentration was measured by a clotting method. When both sexes are considered together, whole blood viscosity shows no significant difference among age groups. Plasma fibrinogen concentration significantly increases with age (P<0.001); hemoglobin, red blood cell count and platelet count, on contrary, are significantly lower in aged group. In the male sex, blood viscosity at higher shear rate (450 s(-1)) negatively correlates with advancing age (P<0.005). The age-related decrease of hematocrit value in the male sex accounts for this occurrence.

Journal Article↗

PubMed1995

Determination of fractal dimension of physiologically characterized neurons in two and three dimensions.

Although there is a growing interest in the application of fractal analysis in neurobiology, questions about the methodology have restricted its wider application. In this report we discuss some of the underlying principles for fractal analysis, we propose the cumulative-mass method as a standard method and we extend the applicability of fractal analysis to both 2 and 3 dimensions. We have examined the relationship between the method of log-log Sholl analysis and fractal analysis and have found that they correlate well. Measurements of physiologically characterized retinal ganglion cells indicate that different cell types can have significantly different fractal dimensions. Such differences may allow the correlation of the physiological type of a neuron with its morphological fractal dimension.

Animals↗

PubMed1992

Anomalous interface roughening in porous media: Experiment and model.

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Journal Article↗

PubMed1992

Effect of viscosity on neurite outgrowth and fractal dimension.

The growth mechanism by which neurons achieve their characteristic ramified morphology has long been of interest, but determining whether physical parameters, such as viscosity, are important has been difficult due to a lack of useful hypotheses and standard reproducible techniques. We have recently shown that neurons exhibit fractal behavior and that their fractal dimension (df) is consistent with a physical process called diffusion-limited aggregation (DLA). We suggested that this DLA behavior might stem from viscosity differences, chemical gradients or electrical fields (Caserta et al., Phys. Rev. Lett., 64 (1990) 95-98). DLA is a model for a large family of growth processes. In order for a process to fit the DLA model, the growth rate must be proportional to the gradient of a field at a point on the growing structure (Feder, Plenum, New York, 1988, Ch. 4). Chemical, electrical, or fluid pressure fields can fit the model depending on the particular physical system under study. Here, we studied growth of retinal neurons from chick embryos in culture media of various fluid viscosities. Thus, we test whether DLA in this system was based on a fluid pressure field. As viscosity was increased from 1 to 4.3 cps, the number of neurite branches decreased 98%. However, there was no effect on df. Over this range of viscosities, total cellular protein synthesis decreased only 17%. The results indicate that, while differences in viscosity between the interior and exterior of the cell affect neurite outgrowth, they do not affect the fractal behavior of neurons. Thus, viscosity differences are not the basis for the DLA pattern of neuronal arborization.

Algorithms↗

PubMed1990