Biomedical subjects

M Laguens

Publications and source records attributed to M Laguens.

8 recordsLinked to original sources

PubMed2006

The potential role of dynamic thermal analysis in breast cancer detection.

BACKGROUND: It is presently well accepted that the breast exhibits a circadian rhythm reflective of its physiology. There is increasing evidence that rhythms associated with malignant cells proliferation are largely non-circadian. Cancer development appears to generate its own thermal signatures and the complexity of these signatures may be a reflection of its degree of development. The limitations of mammography as a screening modality especially in young women with dense breasts necessitated the development of novel and more effective screening strategies with a high sensitivity and specificity. The aim of this prospective study was to evaluate the feasibility of dynamic thermal analysis (DTA) as a potential breast cancer screening tool. METHODS: 173 women undergoing mammography as part of clinical assessment of their breast symptoms were recruited prior to having a biopsy. Thermal data from the breast surface were collected every five minutes for a period of 48 hours using eight thermal sensors placed on each breast surface [First Warning System (FWS), Lifeline Biotechnologies, Florida, USA]. Thermal data were recorded by microprocessors during the test period and analysed using specially developed statistical software. Temperature points from each contra-lateral sensor are plotted against each other to form a thermal motion picture of a lesion's physiological activity. DTA interpretations [positive (abnormal thermal signature) and negative (normal thermal signature)] were compared with mammography and final histology findings. RESULTS: 118 (68%) of participating patients, were found to have breast cancer on final histology. Mammography was diagnostic of malignancy (M5) in 55 (47%), indeterminate (M3, M4) in 54 (46%) and normal/benign (M1, M2) in 9 (8%) patients. DTA data was available on 160 (92.5%) participants. Using our initial algorithm, DTA was interpreted as positive in 113 patients and negative in 47 patients. Abnormal thermal signatures were found in 76 (72%) out of 105 breast cancer patients and 37 of the 55 benign cases. Then we developed a new algorithm using multiple-layer perception and SoftMax output artificial neural networks (ANN) on a subgroup (n = 38) of recorded files. The sensitivity improved to 76% (16/21) and false positives decreased to 26% (7/27) CONCLUSION: DTA of the breast is a feasible, non invasive approach that seems to be sensitive for the detection of breast cancer. However, the test has a limited specificity that can be improved further using ANN. Prospective multi-centre trials are required to validate this promising modality as an adjunct to screening mammography especially in young women with dense breasts.

Journal Article↗

PubMed2003

[A simple method to detect disaccharides deficiency].

A simple method, easy to perform during an endoscopic procedure, fast and inexpensive, that allows detecting deficiencies in lactase, sucrase or maltase activities is presented. Briefly, method consists in placing a duodenal biopsy sample in an adequate vial containing lactose, sucrose or maltose solution during a few minutes, and then, adding a few drops of a glucose reactive from commercial origin. Presence of any enzymatic activity is demonstrated when released glucose from any of the disaccharides chosen reacts with the second reactive, turning solution to a red colour. Its utility is discussed and compared with other diagnostic methods.

Clinical Enzyme Tests↗

PubMed1996

Presence of heat shock protein in chronic periapical pathology of pulpal origin.

In order to establish whether tissues damaged by Chronic Periapical Pathology (CPP) of endodontic origin produced heat shock protein (HSP) capable of attracting reactive lymphocytes, paraffin sections of samples from the oral cavity of 10 patients with CPP were incubated with commercially available anti-HSP monoclonal antibodies. Antibodies were evidenced employing the alkaline phosphatase immunoenzymatic method (DAKO). HSP was found in the lamina propria infiltrated by lymphocytes, in six of the ten samples. These results suggest that HSP may be one of the lymphocyte recruiting factors in the damaged area and opens new possibilities for further research.

Adolescent↗

PubMed1990

Demonstration and characterization of HLA-DR positive cells in the stroma of human endometrium.

The proportion of stromal cells expressing DR antigens of the HLA system or reacting with an anti-macrophage antibody was studied by immunohistochemical methods in human proliferative, secretory and post-menopausal endometria. DR+ cells showed a rounded morphology with short expansions and represented 13-25% of the stromal cells in the proliferative and 16-43% in the secretory endometrium. The cells reacting with the anti-macrophage antibody were similar to DR+ cells, but their number was between 1/2 and 1/10 of DR+ cells. In the post-menopausal endometria no DR+ cells or elements reacting with anti-macrophage antibody were observed. These results suggest that a significant proportion of endometrial stromal cells expressing type II histocompatibility antigens do not belong to the monocyte-phagocyte system and that their number is under hormonal regulation.

Antibodies, Monoclonal↗

PubMed1990

Infection of guinea pigs with two strains of lymphocytic choriomeningitis virus.

In order to study the lesions produced by lymphocytic choriomeningitis virus (LCMV) adult guinea-pigs were inoculated intraperitoneally with 1000 PFU of the WE or the Armstrong strain of LCMV. The animals were sacrificed at 3, 7, 10 and 14 days p.i. and samples were taken for hematological, histopathological and virological studies. In the guinea-pigs infected with the WE strain there was destruction of the splenic red pulp with high titers of virus and different degrees of pneumonitis. The hematological studies showed lymphopenia from day 7 p.i. onwards and focal bone marrow necrosis. In the animals infected with the Armstrong strain there was a very moderate neutropenia and virus multiplication was less than 2 logs, comparing with WE, in every case. The presence of large numbers of polymorphonuclear neutrophil (PMN) in the splenic red pulp and in the lung infiltrate previous to the mentioned lesions, encourage the interpretation that the damage is somehow mediated by these cells. The guinea-pigs infected with the WE strain could represent a very convenient model to study the role of PMN in viral diseases, as well as the non-immune pathogenetic mechanisms for LCMV.

Animals↗

PubMed1987

[Augmentation of the phagocytic activity of monocytes in patients with Darier's disease by the oral administration of retinoic acid].

Other tissue involvement has been described in Darier's disease, eg: susceptibility to infection. In order to know if this susceptibility is due to abnormal phagocytosis and if this can revert by administration of retinoic acid (RA), blood monocyte-derived macrophages, from four individuals with Darier's disease were obtained prior and after administration of RA to determine in them morphological, cytochemical and phagocytic activity changes. It was observed that phagocytosis was diminished and RA administration increased it, without changes in enzyme distribution. This modification of phagocytosis could be due to a reordenation of cytoskeleton.

Administration, Oral↗

PubMed1983

In vivo replication of pathogenic and attenuated strains of Junin virus in different cell populations of lymphatic tissue.

Lymphatic tissue is one of the main sites for replication of Junin virus. To characterize which cells are involved in that replication, the presence of Junin virus in purified populations of macrophages and dendritic cells from the spleens of guinea pigs infected with pathogenic and attenuated strains was investigated by immunofluorescence and intracerebral inoculation into newborn mice. The pathogenic strain was present both in macrophages and in dendritic cells, but the attenuated strain selectively infected dendritic cells. These observations suggest that the pathogenic behavior and replication efficiency of these two strains of Junin virus may be related to a difference in cell targets.

Animals↗

PubMedDate not supplied

Circadian rhythm chaos: a new breast cancer marker.

The most disappointing aspect of breast cancer treatment as a public health issue has been the failure of screening to improve mortality figures. Since treatment of late-stage cancer has indeed advanced, mortality can only be decreased by improving the rate of early diagnosis. From the mid-1950s to the mid-1970s, it was expected that thermography would hold the key to breast cancer detection, as surface temperature increases overlying malignant tumors had been demonstrated by thermographic imaging. Unfortunately, detection of the 1-3 degrees C thermal differences failed to bear out its promise in early identification of cancer. In the intervening two-and-a-half decades, three new factors have emerged: it is now apparent that breast cancer has a lengthy genesis; a long-established tumor-even one of a certain minimum size-induces increased arterial/capillary vascularity in its vicinity; and thermal variations that characterize tissue metabolism are circadian ("about 24 hours") in periodicity. This paper reviews the evidence for a connection between disturbances of circadian rhythms and breast cancer. Furthermore, a scheme is proposed in which circadian rhythm "chaos" is taken as a signal of high risk for breast cancer even in the absence of mammographic evidence of neoplasm or a palpable tumor. Recent studies along this line suggest that an abnormal thermal sign, in the light of our present knowledge of breast cancer, is ten times as important an indication as is family history data.

Breast Neoplasms↗