The role of factor XIIIa in the mesenchymatogenesis of the human placenta: an immunohistochemical analysis.

Human placentas from normal pregnancies [9], interrupted pregnancies due to congenital anomalies of the fetuses [7] and legal abortions [9] were examined immunohistochemically using monoclonal antiserum for factor XIIIa. Hofbauer cells of the chorionic villi were strongly positive for factor XIIIa. Deeper staining in early pregnancy reflects the greater numbers of Hofbauer cells in this period of gestation. Our findings support the hypothesis that the presence of factor XIIIa in the Hofbauer cells promotes the maturation of the chorionic villi.

Primary causes of fetal deaths in Athens a clinicopathological study.

The authors studied 239 cases of fetal death, occurring before the 24th week of gestation, during a five-year period, from 1989 to 1993. Based on clinical information and autopsy findings, their cases were classified as follows: 1) amniotic infection syndrome; 2) congenital anomalies; 3) disorders of the placenta and adnexae, and 4) others. The causes of fetal death were determined and evaluated statistically. In 83 cases (39 %), only autopsy revealed the cause of fetal death. The correlation of clinical and pathological findings showed that autopsy constitutes an important source of information for the determination of causes of fetal death, as well as for future genetic counselling. Moreover, it can broaden our knowledge about perinatal mortality, by correctly interpreting clinical and complementary investigation data.

Lymphocytic thyroiditis in fine-needle aspirates: differential diagnostic aspects.

This study assessed the morphological criteria for the diagnosis of various types of lymphocytic thyroiditis in fine-needle aspirates. Of 950 aspirates, 121 revealed lymphocytic thyroiditis, including Hashimoto's thyroiditis (partly confirmed by serological or histological examination) and focal thyroiditis adjacent to neoplasms. The diagnosis of Hashimoto's thyroiditis was easy when the aspirated material was adequate and contained oxyphilic cells; in the fibrous type, diagnosis was rather difficult. Focal thyroiditis may be confused with Hashimoto's thyroiditis, especially when adjacent to neoplasm. Surgical exploration should be performed in cases of severe lymphocytic thyroiditis revealed by fine-needle aspiration with repeatedly negative antibody titers in order to exclude neoplasm.

A histological and immunohistochemical study of the changes induced in the brains of white mice by infection with Toxoplasma gondii.

The topography and the severity of the brain lesions induced in male and female white mice 1-6 weeks following inoculation with Toxoplasma gondii were studied by conventional histological and peroxidase-antiperoxidase (PAP) immunohistochemical techniques. The medulla oblongata and fourth ventricle were the most severely damaged areas of the brain, while the cerebellum was only minimally involved in this only in the later stages of the disease. Toxoplasma cysts were revealed by the PAP method as early as 2 weeks after infection. The number of cysts and the severity of the lesions increased gradually each week following inoculation. The lymphoplasmacytic element in the lesions was less intense in male than in female mice. The significance of these findings in respect to the possible immunological pathogenesis of CNS toxoplasmic changes is discussed. A correlation of the experimental findings with the known neurologic manifestations of the disease is also attempted. The advantage of the PAP method in the study of toxoplasmic infection is stressed.