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Biomedical subjects

M Sans

Publications and source records attributed to M Sans.

70 records · Page 4Linked to original sources
PubMed1993

Mathematical morphologic analysis of the aortic medial structure. Biomechanical implications.

The architecture of the aortic tunica media was studied in 55 autopsy specimens (26 normotensive and 29 hypertensive patients). The purpose of the study was to elucidate whether, as commonly stated, homogeneous disposition of concentric lamellar units could be substantiated or whether an architectural gradient reflecting the decreasing biomechanical gradient in the circumferential stress, concentrated towards the inner wall, was present. The elastin lamellae thickness, interlamellar distance, fibrosis index and fragmentation index were quantitated by mathematical morphology methods. The results did not support classic histologic descriptions but showed that lamellar units were significantly thicker in the inner than in the outer zones of the media--i.e., a morphologic gradient was present. The differences between inner and outer zones were more marked in hypertensive patients than in controls. The fibrosis index increased with age, especially in hypertensive patients. The fragmentation index in hypertensive patients was significantly higher than in controls and more marked in abdominal than in thoracic aorta. This weakening in the biomechanical resistance of elastin fibers could be one of the factors explaining the predominance of aneurysms in the abdominal aorta.

Adult↗
PubMed1993

Textural analysis of lymphoid cells in serous effusions. A mathematical morphologic approach.

Nuclear texture of reactive and well-differentiated neoplastic lymphocytes from serous effusions was studied by an approach based on principles of mathematical morphology. Density features were obtained before and after gray level nuclear image transformation by morphologic closing (dilation followed by erosion) and application of a top-hat function, which detects light or dense spots with a determined width and contrast. Five cases of benign reactive lymphocytic serous effusions and 11 cases of effusions in well-differentiated lymphocytic lymphomas were analyzed retrospectively. Each lymphoid cell was characterized by 24 densitometric features. Rank-order transformation was used for linear discriminant analysis given non-normal distributions of variables. In a first model formed by pooling all cells, discriminant function distinguished between 110 reactive and 216 malignant lymphocytes in the learning set and between 111 reactive and 226 malignant lymphocytes in the test set with better than 81% accuracy in both. In a second model, correct classification of cases as reactive or malignant was achieved in 5/5 reactive and 11/11 malignant lymphoid effusions. The results indicate that mathematical morphologic transformations of the gray level image may be an effective adjunct to other textural descriptors of cellular atypia, especially in the differential diagnosis of lymphoid serous effusions.

Ascitic Fluid↗
PubMed1993

Fine needle aspiration diagnosis of renal oncocytoma. A mathematical morphologic approach.

Differentiation between renal oncocytomas and well-differentiated oxyphilic cell renal carcinomas from fine needle aspiration cytology smears may present considerable difficulties. To better define diagnostic criteria, we used high-resolution architectural characteristics of nucleus and cytoplasm based on mathematical morphologic concepts. Particulate structural elements were selected for their size and optical density by the so-called top-hat function. Spatial density, size distribution and a function of distance between particles were computed. We quantitated cellular samples from fine needle aspirates obtained from 10 renal oncocytomas and 5 well-differentiated oxyphilic cell renal carcinomas. In two of the former, cytologic diagnosis was doubtful. Subsequent removal of the tumor and its histologic examination established the final diagnosis in all cases. Stepwise discriminant analysis correctly classified all cases as oncocytomas or renal carcinomas, although the results need to be considered with caution due to the necessarily limited number of observations. Multivariate graphic representation by star glyphs clearly depicted the differences between oncocytoma and oxyphilic cell renal carcinomas and the abnormal characteristics of two oncocytoma cases misclassified initially.

Adenoma↗
PubMed1992

Cirrhotic changes in livers from children undergoing transplantation. Image analysis.

The pattern and extent of disorganization of the liver architecture were studied in 25 children undergoing orthotopic liver transplantation for cirrhosis. Image analysis techniques based on mathematical morphology were used to define seven parameters for each case, including fibrosis index (percentage of Sirius-red-stained areas), three categories of regenerative nodules (< 0.8, 0.8-1.6 and > 1.6 mm in diameter) and three categories of fibrous septa (< 0.4, 0.4-1.2 and > 1.2 mm in width). Fibrosis index ranged from 10.2% to 51.9%. Percentage of small nodules of infralobular size (< 0.8 mm in diameter) varied from 31.4% to 98.2%. Percentage of large nodules, > 1.6 mm in diameter, in only four cases was > 15%. Multivariate clustering analysis classified the cases into three main groups. One of them included only cases of cirrhosis secondary to parenchymal disease or to inborn errors of metabolism. In their pattern, tiny nodules predominated, and the percentage of slender septa, < 0.4 mm in diameter, was very high, although the overall fibrosis index was relatively low. Patients with biliary cirrhosis were classified into two groups. In one the fibrosis index was low and the size of the nodules variable, with 12% large nodules. In the other the fibrosis index was high, and small nodules, < 0.8 mm in diameter, predominated. No relationship was found with age at transplantation or previous portoenterostomy. A presumptive explanation for this divergent evolution might be the occurrence of cholangitic episodes. Overall fibrosis that the liver can sustain without failure is apparently limited.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Mathematical morphologic analysis of liver cirrhosis. Correlation with etiology, clinical score and hepatocellular carcinoma.

Remodeling of the cirrhotic liver was studied retrospectively by mathematical morphologic methods in 75 autopsy cases (40 alcoholic, 17 hepatitis B virus (HBV)-related and 18 cryptogenetic cirrhosis), including 28 hepatocellular carcinomas. The aim was to obtain objective measurements of cirrhotic patterns that could be correlated with liver function evaluated by the Pugh-Child score, establish the relationship among different morphogenetic features and evaluate the implications of an objective classification of cases by numerical taxonomy in terms of their etiology, liver function and malignant transformation. The results indicate that the Pugh-Child score was closely related to the global amount of fibrosis or to the percentage of regenerative nodules < 0.8 mm in diameter. In contrast, the higher the percentage of lobular-sized regenerative nodules (0.8-1.6 mm), the better the functional score, suggesting that they are probably residual lobules, albeit completely surrounded by fibrous tissue, rather than true regenerative pseudolobules. The four groups of cases obtained by numerical taxonomy (cluster analysis) showed different distributions for alcoholic and HBV-related cirrhosis. The pattern of the latter was practically analogous to that in classically labeled cryptogenetic cirrhosis, suggesting its viral etiology. Taxonomic classification had functional implications. The Pugh-Child score showed a definite relationship with the different clusters obtained. The incidence of malignant transformation gradually decreased from group G1 to G4, with a steeper descent between G2 and G3. These results might contribute to a more dynamic concept of morphologic changes in liver biopsies from patients with cirrhosis.

Adult↗
PubMed1989

Epithelioid hemangioendothelioma of the liver with myocardial metastases.

Epithelioid hemangioendothelioma is an unusual type of endothelial-derived vascular tumor located mainly in the soft tissues of the limbs. The present report describes a 48-year-old woman with an epithelioid hemangioendothelioma located in the liver with very unusual metastases to the myocardium. While the disease itself was controlled by adriamycin the patient died as a consequence of portal hypertension due to the abundant fibrotic component distinctive of this type of tumor. An epithelioid appearance can sometimes lead to a mistaken diagnosis of metastatic carcinoma, as happened initially in our case. The endothelial origin of the tumor must be confirmed by electron microscope identification of Weibel-Palade bodies or by immunohistochemical staining of factor VIII-related antigen. To the authors knowledge, this is the first case of myocardial metastases from an epithelioid hemangioendothelioma of the liver to be reported in English in the medical literature.

Female↗
PubMed1981

[Hepatic angiosarcomas].

The authors describe three cases of hepatic angiosarcoma diagnosed at postmortem examination, two of them being associated to thorium dioxide. The low incidence of these tumors amongst the general population is commented upon, and an update is made on the factors involved in their appearance, with special mention of thorium dioxide. An analysis of the clinical picture of the disease is undertaken, emphasizing its diagnostic difficulties. A tentative diagnosis can be made on the basis of clear-cut epidemiological data and or the presence of increased radiological density over the liver, spleen and paraaortic lymph nodes in the cases associated to thorium dioxide. Two of the reported patients presented hemolytic anemia, and disseminated intravascular coagulation, respectively; these findings, although nonspecific, may suggest the diagnosis in the presence of a toxic clinical picture or one of the above mentioned factors. The diagnosis should be made by the usual techniques utilized clinically to detect space occupying lesions within the liver. The evolution of such patients is rapidly progressive, with a fatal outcome within three to six months after beginning of symptoms.

Aged↗
PubMed1980

Asphyxia caused by laryngeal impaction of an esophageal polyp.

We report a case of asphyxia due to laryngeal obstruction by an esophageal polyp with subsequent cerebral anoxia and death. We review the clinical manifestations and pathological aspects of benign esophageal tumors, with emphasis on the importance of an early diagnosis if a patient has repeated sensations of a regurgitated pharyngeal mass.

Asphyxia↗
PubMed1980

Masculinization of a female fetus by Krukenberg tumor during pregnancy.

A case of fetal masculinization resulting from a Krukenberg tumor in a pregnant woman is reported in a newborn infant with a sexual ambiguity of the external genitals, of the feminine pseudohermaphrodite type. She also had an incarceration of both ovaries and tubes in a right inguinoscrotal hernia that was surgically corrected.

Disorders of Sex Development↗
PubMedDate not supplied

Consanguinity in two Uruguayan cities: historical evolution and characteristics (1800--1994).

BACKGROUND: Information about consanguinity in Uruguay is scarce and limited to the end of the 20th century. AIM: To determine the frequency and characteristics of consanguineous marriages, as well as chronological trends, in two Uruguayan cities over almost two centuries. SUBJECTS AND METHODS: We analysed 28,393 Roman Catholic Church marriage records and Diocesan consanguinity dispensations belonging to the cities of Melo (Northeast), and Montevideo (South), for the period 1800--1994. RESULTS: 633 (2.23%) marriages were consanguineous. Among them, first cousin marriages were the most common (58.8% of all consanguineous marriages, including double consanguineous), especially those where the bride and groom were related through their maternal side. During the first decades of the 19th century both regions showed low levels of consanguinity. Consanguinity reached its maximum during the mid-1800s and decreased significantly throughout the 20th century. The overall mean coefficients of inbreeding were moderate in both cases, being greater in the Northeast (alpha=0.00165) than in the South (alpha = 0.00089). CONCLUSIONS: The low level of consanguinity as well as the structure of consanguineous marriages (distribution by degrees) is similar to that found in other southern South American countries. Temporal trends are similar to those found in industrialized regions in Europe, with maximum inbreeding levels during the middle-late 19th century; however, the clear predominance of first cousin unions, differs from most of the data for European countries. Small differences between the two cities can be related to diverse facts, such as socio-economic conditions, ethnic origin, immigration, and sampling.

Consanguinity↗
PubMedDate not supplied

Platelets: new players in the mucosal scenario of inflammatory bowel disease.

Besides their classical haemostatic task, platelets are now recognized as novel cells deeply involved in inflammation. Compelling evidence support their role as active player in mucosal tissue injury that occurs in Crohn's disease and ulcerative colitis. In both forms of inflammatory bowel disease platelets contribute to microvascular endothelial activation and recruitment of inflammatory cells, thus fostering and amplifying mucosal inflammation.

Blood Platelets↗