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Biomedical subjects

Carlo Russo

Publications and source records attributed to Carlo Russo.

8 recordsLinked to original sources
PubMed2006

Sampling variability of computer-aided fractal-corrected measures of liver fibrosis in needle biopsy specimens.

AIM: To assess the sampling variability of computer-aided, fractal-corrected measures of fibrosis in liver biopsies. METHODS: Samples were derived from six to eight different parts of livers removed from 12 patients with clinically and histologically proven cirrhosis undergoing orthotopic liver transplantation. Sirius red-stained sections with a thickness of 2 mum were digitized using a computer-aided image analysis system that automatically measures the surface of fibrosis, as well as its outline perimeter, fractal surface and outline dimensions, wrinkledness, and Hurst coefficient. RESULTS: We found a high degree of inter-sample variability in the measurements of the surface [coefficient of variation (CV) = 43% +/- 13%] and wrinkledness (CV = 28% +/- 9%) of fibrosis, but the inter-sample variability of Hurst's exponent was low (CV = 14% +/- 2%). CONCLUSION: This study suggests that Hurst's exponent might be used in clinical practice as the best histological estimate of fibrosis in the whole organ, and evidences the fact that biopsy sections, which are fundamental for the qualitative diagnosis of chronic hepatitis, play a key role in the quantitative estimate of architectural changes in liver tissue.

Biopsy, Needle↗
PubMed2006

The complex functions of mast cells in chronic human liver diseases.

Mast cells (MCs) are multifunctional effector cells of the immune system. MCs were originally thought to be involved in IgE-associated immediate hypersensitivity and allergic disorders, but it is now known that they contain or elaborate an array of mediators with a multitude of effects on many other cells. A number of studies have found that MCs are involved in various liver diseases. Although still controversial, they seem to be involved in the liver's fibrotic response to chronic inflammation and parasitic infection. Hepatic fibrosis is the most frequent liver response to toxic, infectious, or metabolic agents. During the establishment of this pathological condition, there is an increase in the components of the basement membrane that leads to continuous basement membrane-like structures being raised within Disse's space and a decrease in the number of sinusoid endothelial fenestrae. This leads to a complex process called "sinusoidal capillarization." At the cellular level, liver fibrogenesis is initiated by hepatocyte necrosis, which induces the recruitment of a large number of inflammatory cells, including MCs, which can be considered the primary effectors of the process changing sinusoidal endothelial cells into capillary-type endothelial cells. We review the roles played by MCs in hepatic chronic diseases and describe a biopsy section of hepatic tissue taken from a patient with chronic C virus-related hepatitis showing diffuse sinusoidal capillarization and a high density of MCs. This observation has led us to hypothesize a relationship between these highly specialized cells and sinusoidal capillarization.

Capillaries↗
PubMed2006

Cancer initiation and progression: an unsimplifiable complexity.

BACKGROUND: Cancer remains one of the most complex diseases affecting humans and, despite the impressive advances that have been made in molecular and cell biology, how cancer cells progress through carcinogenesis and acquire their metastatic ability is still widely debated. CONCLUSION: There is no doubt that human carcinogenesis is a dynamic process that depends on a large number of variables and is regulated at multiple spatial and temporal scales. Viewing cancer as a system that is dynamically complex in time and space will, however, probably reveal more about its underlying behavioural characteristics. It is encouraging that mathematicians, biologists and clinicians continue to contribute together towards a common quantitative understanding of cancer complexity. This way of thinking may further help to clarify concepts, interpret new and old experimental data, indicate alternative experiments and categorize the acquired knowledge on the basis of the similarities and/or shared behaviours of very different tumours.

Algorithms↗
PubMed2006

Liver fibrosis and tissue architectural change measurement using fractal-rectified metrics and Hurst's exponent.

AIM: To provide the accurate alternative metrical means of monitoring the effects of new antiviral drugs on the reversal of newly formed collagen. METHODS: Digitized histological biopsy sections taken from 209 patients with chronic C virus hepatitis with different grade of fibrosis or cirrhosis, were measured by means of a new, rapid, user-friendly, fully computer-aided method based on the international system meter rectified using fractal principles. RESULTS: The following were described: geometric perimeter, area and wrinkledness of fibrosis; the collation of the Knodell, Sheuer, Ishak and METAVIR scores with fractal-rectified metric measurements; the meaning of the physical composition of fibrosis in relation to the magnitude of collagen islets; the intra- and inter-biopsy sample variability of these parameters; the"staging" of biopsy sections indicating the pathway covered by fibrosis formation towards its maximum known value; the quantitative liver tissue architectural changes with the Hurst exponent. CONCLUSION: Our model provides the first metrical evaluations of the geometric properties of fibrosis and the quantitative architectural changes of the liver tissue. The representativeness of histological sections of the whole liver is also discussed in the light of the results obtained with the Hurst coefficient.

Adult↗
PubMed2005

Quantitative evaluation and modeling of two-dimensional neovascular network complexity: the surface fractal dimension.

BACKGROUND: Modeling the complex development and growth of tumor angiogenesis using mathematics and biological data is a burgeoning area of cancer research. Architectural complexity is the main feature of every anatomical system, including organs, tissues, cells and sub-cellular entities. The vascular system is a complex network whose geometrical characteristics cannot be properly defined using the principles of Euclidean geometry, which is only capable of interpreting regular and smooth objects that are almost impossible to find in Nature. However, fractal geometry is a more powerful means of quantifying the spatial complexity of real objects. METHODS: This paper introduces the surface fractal dimension (Ds) as a numerical index of the two-dimensional (2-D) geometrical complexity of tumor vascular networks, and their behavior during computer-simulated changes in vessel density and distribution. RESULTS: We show that Ds significantly depends on the number of vessels and their pattern of distribution. This demonstrates that the quantitative evaluation of the 2-D geometrical complexity of tumor vascular systems can be useful not only to measure its complex architecture, but also to model its development and growth. CONCLUSIONS: Studying the fractal properties of neovascularity induces reflections upon the real significance of the complex form of branched anatomical structures, in an attempt to define more appropriate methods of describing them quantitatively. This knowledge can be used to predict the aggressiveness of malignant tumors and design compounds that can halt the process of angiogenesis and influence tumor growth.

Computer Simulation↗
PubMed2003

Fractal dimension rectified meter for quantification of liver fibrosis and other irregular microscopic objects.

OBJECTIVE: To introduce a new mathematical method based on the principles of fractal geometry analysis that permits more realistic quantification of some of the physical (morphologic) aspects of irregular bodies appearing under microscopy. STUDY DESIGN: The principles of the method were tested on microscopic images of irregular collagen deposition in liver tissue. The method uses an ad hoc rectified meter implemented in a computer-assisted planar image analysis system that has been adapted to give metric measures of irregular outlines and surfaces that can be used to produce an index capable of quantifying the typical wrinkledness of biologic objects. Prototypical example measures of liver fibrosis were made on biopsy specimens showing chronic hepatitis C virus-related disease. Measurements were also made of the microscopic images of the abnormal deposition of lipid droplets in hepatocytes, a case of amyloid deposition in an osteoarthromuscular structure and a cytologic specimen of human dendritic cells. RESULTS: The proposed computer-aided method permits rapid measurements of the image of a whole biopsy section digitized at high magnification. The snapshot measurement of liver fibrosis deposition offered by a biopsy pattern is a valid means of more rigorously identifying the staging of the process. CONCLUSION: This method can measure liver fibrosis during chronic liver disease as well as any other irregular biologic structure that cannot be correctly quantified using traditional Euclidean-based metric methodologies.

Biopsy, Needle↗
PubMedDate not supplied

The role of amino acids in corneal stromal healing: a method for evaluating cellular density and extracellular matrix distribution.

PURPOSE: To evaluate how amino acid supplementation influences the response of corneal stromal keratocytes and other components of the corneal stroma. METHODS: We compared two groups of patients undergoing cataract surgery. Each group included 20 eyes of 20 patients. Patients in Group 1 were treated with amino acids for 15 days before surgery, and patients in Group 2 did not receive amino acids (control). To evaluate differences and change in corneal stroma, we analyzed all of the operated corneas with confocal microscopy. The confocal images were then analyzed with a new method for measurement of corneal structure based on fractal dimension calculation. This led to a numerical value, D index (fractal surface dimension), an objective measurement of corneal stromal characteristics. This index is related to three factors: keratocyte density, stromal distribution pattern, and intercellular matrix structure. RESULTS: Patients in the preoperative amino acid group showed higher keratocyte density values than those in the control group. We observed differences in cell distribution patterns and intercellular matrix structures between groups. Amino acid-treated patients had a corneal stroma with a D index value 10% higher than control group patients. CONCLUSIONS: We hypothesized that preoperative oral supplements with amino acids may change the corneal stroma structure by increasing keratocyte density and modifying the intercellular matrix. A new method for the measurement of these changes was applied, which provides quantification of the stromal structure complexity with a single numerical value.

Amino Acids↗