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M Chimenti

Publications and source records attributed to M Chimenti.

9 recordsLinked to original sources
PubMed2004

LEGO bricks used as chemotactic chambers: evaluation by a computer-assisted image analysis technique.

One of the main techniques used to explore neutrophil motility, employs micropore filters in chemotactic chambers. Many new models have been proposed, in order to perform multiple microassays in a rapid, inexpensive and reproducible way. In this work, LEGO bricks have been used as chemotactic chambers in the evaluation of neutrophil random motility and chemotaxis and compared with conventional Boyden chambers in a "time-response" experiment. Neutrophil motility throughout the filters was evaluated by means of an image-processing workstation, in which a dedicated algorithm recognizes and counts the cells in several fields and focal planes throughout the whole filter; correlates counts and depth values; performs a statistical analysis of data; calculates the true value of neutrophil migration; determines the distribution of cells; and displays the migration pattern. By this method, we found that the distances travelled by the cells in conventional chambers and in LEGO bricks were perfectly identical, both in random migration and under chemotactic conditions. Moreover, no interference with the physiological behaviour of neutrophils was detectable. In fact, the kinetics of migration was identical both in random migration (characterized by a gaussian pattern) and in chemotaxis (characterized by a typical stimulation peak, previously identified by our workstation). In conclusion, LEGO bricks are extremely precise devices. They are simple to use and allow the use of small amounts of chemoattractant solution and cell suspension, supplying by itself a triplicate test. LEGO bricks are inexpensive, fast and suitable for current diagnostic activity or for research investigations in every laboratory.

Cell Culture Techniques↗
PubMed1999

A Study on Vascular Retinal Alterations in Patients with Coronary Artery Disease.

The paper describes the study carried out on a sample of 27 coronary artery disease patients, aiming to determine a correlation between coronary artery disease and anomalies in the retinal circulation. Patients underwent selective coronary arteriography and fundus fluorescein angiography that allowed us to investigate the dye dynamics and to detect abnormalities of time evolution, vessel walls, and flux. During the fluorescein angiography we measured time events as the choroidal flush (ta) the start of the laminar phase (tb), and the end of the laminar phase (tc) and we took pictures that were digitally processed in order to compute the ROI1/ROI2 value, assumed as a numerical index of ischemia of the optic disc. In the examined sample we found ta = 61 +/- 109, tb = 65 +/- 107, tc = 159 +/- 155, and ROI1/ROI2 = 0.968 +/- 0.300. Normal ranges for these parameters were determined by the fundus fluorescein angiography of a control group of 10 patients, unaffected by coronary artery disease and ischemic pathology of the retinal network; we found ta = 12 +/- 4, tb = 16 +/- 8.5, tc = 44 +/- 9.3, and ROI1/ROI2 = 0.735 +/- 0.086. Eighty-five percent of coronaropatic patients showed ischemia of the optic disc, 89% anomalies of the epi-peripapillar network, 70% anomalies of the papillo-macular network, and 89% evidence of at least two findings of ischemia; 85% of patients showed a value of ROI1/ROI2 out of the normal range. The unpaired Student's t-test between the coronaropatic and the control group does not show significant differences between ta and tb; on the contrary, those with coronary disease and the control group were statistically different for tc (p </= 0.02). Moreover, we have found a correlation between the numerical index of optic disc ischemia and the severity of coronary artery disease (r = 0.68, p </= 0.01). Hence, the vascular abnormalities shown by the fluorescein angiography can constitute valid noninvasive markers and can advise further cardiological tests for a coronary artery disease not yet diagnosed.

Journal Article↗
PubMed1995

An image processing procedure for the assessment of normality curves of motility of human granulocytes in micropore filters.

With the conventional methods used in current practice, the results of human granulocyte motility assays are expressed by a numerical value that defines the leading front of cells into micropore filters. The authors have developed a fast procedure which allows the complete curve of polymorphonuclear leukocyte (PMN) migration to be obtained, from the initial plane of a filter to the maximum propagation depth. In this way, more information is given than that expressed by a single parameter. The paper describes the procedure used to determine the normality curves both for random and stimulated migration, according to a simple model which defines the PMN propagation in micropore filters. A normality band that defines variations due to the stochastic process is also reported.

Cell Movement↗
PubMed1993

A computer-assisted method for the study of the trabecular bone of the distal radius on conventional radiographs.

The procedure described is based on the acquisition and processing of x-rays of the distal radius obtained under standard conditions. An x-ray was obtained of the forearm together with an aluminum step wedge to automatically normalize the photometric values of the bone with respect to the photometric values of the reference aluminum wedge. Densitometric values for thickness (T) and a coarseness parameter (C) that depends on the trabecular bone pattern are measured on interactively selected rows and regions of interest (ROIs) of the digital image. Twenty-five women were examined and two different measurements were performed. The first measurement considers C in three sites of the radial epiphisis. The trabecular bone coarseness appears to increase from the distal to the very-very distal site and the value of C in the very distal site, which is located 1 cm distally to the distal one tenth of the radius, seems to be related to the pathological variations more than the value of C in the other sites. The second measurement is the C/T ratio of eight ROIs of 15 patients: five healthy and 10 osteoporotic women. This ratio is significantly different for the two groups in all the eight ROIs and the variations are particularly significant at 6 to 12 mm from the subchondral line.

Absorptiometry, Photon↗
PubMed1993

Gallium-67 scintigraphy in an AIDS patients presenting tuberculous pericarditis.

The case of a 31-year-old HIV-positive male drug addict, with a history of recurrent intermittent fever is presented. Chest x-ray showed right ilar-node enlargement and moderate venous congestion. A 67Ga-citrate scan of the chest was highly suggestive of Mycobacterial infection. Scans showed right supraclavicular, right costophrenic, hilar node, pericardial and low grade pulmonary tracer uptake. Therapy with streptomycin, ethambutol, isoniazid and pyrazinamide was started. After 8 weeks, a chest roentgenogram was normal and 67Ga-citrate scintigraphy showed only right hilar node tracer uptake. Biopsy specimen cultures then confirmed the diagnosis of Mycobacterium tuberculosis infection. This case is interesting because of (1) the uncommon pericardial tracer uptake, and (2) because it confirms the usefulness of 67Ga-citrate scan for the early diagnosis of Mycobacterial infection.

AIDS-Related Opportunistic Infections↗
PubMed1992

An image processing workstation for automatic evaluation of human granulocyte motility.

Polymorphonuclear (PMN) motility is currently determined by a method using chemotactic chambers with micropore filters. PMN locomotive capacity is measured by evaluating the maximum distance travelled by the cells, or by counting the number of cells which have moved through the filter. Although in recent years some attempts to improve the analysis of chemotaxis data by computer-assisted systems have been made no technique has been shown capable of both measurement and correlation of these parameters in real time. In the present paper we describe an automated technique, based on a workstation capable of exploring microporous filters employed in chemotactic chambers and of measuring PMN motility in a reliable, reproducible, rapid manner, independent of the subjectivity of the operator. The measurement is carried out by custom software capable of undertaking computerized image analysis of microscopic fields acquired by a TV camera and of driving the motorized microscopic table. Depth of migration, cell distribution at each plane, correlation index of the random behaviour with the model described by a gaussian distribution and data about the patient or assay under study, are computed, displayed, stored in a data base and printed in real time.

Algorithms↗
PubMed1989

Decrease of diffusion of glycosylated albumin in retinal microcirculation by peptide fraction from bovine factor VIII.

The diffusion of the glycosylated albumin in the retinal vascular system has been studied in male New Zealand rabbits, using fluorangiographic techniques. A first group of animals was treated for 15 days with the peptide fraction from bovine Factor VIII (Vueffe); a second group, used as control group, was treated with physiological solution. At the end of treatment, glycosylated albumin was made fluorescent and then injected into the marginal vein of the rabbit. The direct observation and the photometric measurements performed on the digitized photograms with an image processing system showed a considerable reduction in retinic capillary diffusion of glycosylated albumin in the animals treated with the peptide fraction. The substance used in the study might therefore be of importance in the treatment of systemic disease with retinic vascular damage.

Angiography↗