Distribution of Taenia solium Diagnostic Glycoproteins in the Different Developmental Stages of the Parasite.

Taenia solium is a helminth parasite that causes 2 diseases in humans: cysticercosis and taeniasis. The establishment of T. solium metacestodes in the central nervous system causes neurocysticercosis, while development of the adult tapeworm in the small intestine causes taeniasis. Serological diagnosis of neurocysticercosis is performed by Western blot with an enriched fraction of glycoproteins that has been extensively used for clinical diagnosis and epidemiological surveys. The lectin-bound fraction that is used for this assay contains 7 antigenic glycoproteins. These antigenic proteins are considered to be highly specific for cysticercosis when tested with heterologous parasitic diseases. However, recent studies show that people with taeniasis have cross-reactive antibodies against the neurocysticercosis diagnostic glycoproteins and vice versa. Nevertheless, it is not known if these diagnostic proteins are expressed in the adult stage of the parasite. In this paper, we describe the location of 3 of these glycoproteins in T. solium adults and cysticerci using polyclonal antibodies raised against a synthetic peptide based on the amino acid sequence of TS14, a recombinant protein T24H, and the native GP50. The glycoproteins' distribution was different in invaginated and evaginated cysticerci as well as in adult tapeworms. Specifically, the 3 glycoproteins studied were differentially expressed during embryogenesis. Our findings indicate that expression of the diagnostic glycoproteins is developmentally regulated; this is noteworthy since these glycoproteins are considered specific for the diagnosis of neurocysticercosis but nevertheless are present in different structures throughout the development of T. solium. Here we describe the glycoprotein expression and localization, which can be important in understanding their biological functions. In addition, our results help clarify the cross-reaction observed between people with neurocysticercosis and taeniasis to TS14, T24H, and GP50, which are used as diagnostic antigens for neurocysticercosis.

[Ultrastructural study of placentas from HIV seropositive women]. / Estudio ultraestructural de placentas en mujeres seropositivas para el VIH.

Eleven placentas from seropositive women for HIV, were analyzed. In three cases the material came from first trimester abortions and the other eight from term pregnancies. In five cases retroviruses were identified, similar to HIV in the placental tissue. It was demonstrated for the first time the internalization of a retrovirus and its presence in the syncytiotrophoblast. It is communicated for the first time the presence of one cell in the placental stroma different to Hofbauer's by its granules type.

[Infectivity of the entomopathogenic fungus Verticillium lecanii in mice and guinea pigs]. / Infectividad del hongo entomopatógeno Verticillium lecanii en ratones y cobayos.

The resistance of plague insects to chemical insecticides as well as the importance of a healthy environment demands an alternative for agricultural plagues. Among others, biological control seems an alternate strategy with fungal entomopathogens playing a relevant role. The hyphomycete Verticillium lecanii is a natural bioregulator of aphids, scales and white-flies that attack different agricultural plantations. Its use in biological control programs must be assessed previously by safety procedures such as its innocuity in mammals and useful animals and plants. The aim of this study was pointed at demonstrating the innocuity of V. lecanii in mice and guinea pigs. Two strains of the fungus were injected intraperitoneally (10(8) conidia/kg of animal weight) to 130 mice and 66 guinea pigs. Two control groups were included, one injected with heat-killed fungi and the other with sterile physiological saline. The animals were killed at 8, 30 and 70 days after infection, and mycological and histopathological studies performed in their organs. Negative results obtained with the live fungus in the same manner as the two control groups, suggest the innocuity of V. lecanii in mice and guinea pigs.

Ultrastructural findings in placentae of HIV-positive women.

PIP: Transmission of human immunodeficiency virus (HIV) from an infected mother to the fetus has been shown to occur. The route of infection is probably through the placenta, yet the exact mechanism of how this occurs is still unclear. Researchers in Mexico report in this article their findings on placental tissue taken from 9 HIV-seropositive women. The placentas from new deliveries were sectioned and the tissue fixed and embedded in plastic. Thin sections were cut, stained, and examined using transmission electron microscopy (TEM). HIV-like particles were found near or inside the trophoblastic villi in 4 placental specimens examined. In one case these particles were found in the endothelium of the umbilical artery. Mast-like cells were found in the free villous stroma in 2 tissue samples. Vertical transmission of HIV has been a major source of HIV infections in Europe and the US. On the other hand, Mexico doesn't report similar findings. The authors suggest that this is the case because of lower female drug use. It is still unclear why some babies from HIV-seropositive mothers become infected while others do not.^ieng

Adenosine triphosphatase-positive Langerhans-like cells in the epidermis of the chicken (Gallus gallus).

In mammalian epidermis a population of ATPase-positive dendritic cells, identified as Langerhans cells, has been found. Such cells are bone marrow-derived and participate in the immunological functions of the skin. We demonstrate the existence of ATPase-positive dendritic cells in separated epidermal sheets of chicken skin, by means of light and electron microscopy. They have a mean distribution of 688 +/- 265 cells/mm2 and showed several features in common with Langerhans cells. Since chickens can develop contact dermatitis, the finding is taken as the first formal demonstration of the presence of Langerhans cells in this group of vertebrates.

Langerhans-like cells in amphibian epidermis.

Langerhans cells have been described in epidermis and other stratified epithelia of mammals. In other vertebrates equivalent cells have not been found. Amphibians show skin graft rejection, so it is possible that these animals have epidermal cells homologous to Langerhans cells. In this work we demonstrate the existence of ATPase-positive dendritic cells in frog epidermis that are similar ultrastructurally to mammalian Langerhans cells, except for the absence of Birbeck granules.

Giant cytoplasmic granules in Langerhans cells of Chediak-Higashi syndrome.

Giant membrane-bound cytoplasmic granules were found in the epidermal Langerhans cells of a patient with the Chediak-Higashi syndrome. These cells also contained normal-appearing Birbeck granules. The giant granules had a granular or sometimes globular internal structure; they are believed to derive from fusion of lysosomes or some portion of Birbeck granules. It is unclear whether this morphologic change in Langerhans cell interferes with their antigen-presenting function; it may be, in part, responsible for the frequent infections seen in patients with Chediak-Higashi syndrome that are otherwise more clearly related to the abnormalities in neutrophils and lymphocytes. The Langerhans cell is another cellular type in Chediak-Higashi syndrome in which giant cytoplasmic granules are found.

Use of absorbable sutures in canine carotid arteries.

To study the functional and microstructural characteristics of polydioxanone sutures in vascular surgery, we created 48 vascular anastomoses in the right and left common carotid arteries of 24 mongrel dogs. In each animal, polydioxanone sutures were used in 1 carotid artery, and polypropylene sutures were used in the contralateral carotid artery. Twelve groups of 2 animals each were then formed. The 1st group was observed for 1 month, the 2nd for 2 months, the 3rd for 3 months, and so on until the 12th group, which was observed for 12 months. At the end of each observation period, reoperation was undertaken to evaluate the vascular anastomoses by means of angiography and microscopy. The polypropylene anastomoses showed a marked deformity, with tissue retraction and a foreign body reaction. In contrast, the polydioxanone anastomoses exhibited satisfactory healing, without deformity, and were well tolerated histologically. We believe that polydioxanone may be a useful, alternative vascular suture material.

Mitosis and polykaryon formation of Entamoeba histolytica in axenic cultures.

Axenic cultures of E. histolytica were established in Coplin jars containing glass slides. The cultures were harvested after 72 hours, fixed and stained with Giemsa and acridine orange. Sedimented parasites were used for inclusion in methacrylate for thin sections that were stained with acridine orange, and epon-araldite for ultrathin sections for electron microscope study. The Giemsa stain showed trophozoites of different sizes and variation in the shape, size and number of the nuclei. Division occurred by budding, sometimes by fission, with occasionally apparent extrusion of nuclear material into the cytoplasm. Acridine orange demonstrated DNA in the center of the nuclei and within intranuclear small vesicles. The electron microscope showed mono and multinucleated amoebae with irregular nuclear membranes, coarse material attached to the nuclear membrane, and sometimes intranuclear parallel microtubules without nuclear attachment. There were structures around the karyosome in some nuclei resembling chromosomic material of superior eukaryotes, without kinetochore, as well as intranuclear small vesicles containing sausage-shaped structures. The findings suggest that E. histolytica undergoes polyploidy evidenced by giant nuclei, followed by segregation of chromatin in smaller nuclei, by budding and production of polykaryons of different nuclear size. Multiple small intranuclear vesicles containing structures that may represent forms of rRNA thus contributing to ribosomes. Absence of cytokinesis is the cause of the production of polykaryons with an asynchronous rate of nuclear and cytoplasmic division. Polynucleation also could be related in the origin of cyst formation in amoeba, as unknown selective forces may induce amoebae the synthesis of chitin capsule.

Osler-Weber-Rendu disease in an infant.

A 23-month-old girl with Osler-Weber-Rendu (OWR) disease manifested by hemoptysis died of massive pulmonary hemorrhage. Autopsy showed predominant respiratory tract involvement, but telangiectatic vessels were also present in other sites. Skin lesions were absent. A grandfather had died after bleeding by mouth following physical exertion. This disease seldom appears in children and hemorrhage usually manifests after 30 years of age.

Lymphoid papillary hyperplasia of the palatine tonsils.

A rare case of papillary hyperplasia of the palatine tonsils is reported in a 9-year-old girl who presented with pharyngeal obstruction. The obstruction was due to the bilateral enlargement of the palatine tonsils with a papillary surface configuration so atypical that a diagnosis of malignant neoplasm was clinically considered. Histopathological study showed a peculiar form of lymphoid hyperplasia. No other members of the family were affected. As far as we know, this is the only case reported in recent years in an Occidental patient although a few similar cases have been reported from Japan. The importance of recognizing this peculiar abnormality rests in the fact that in spite of the clinical features simulating a cancer or multiple epithelial papillomas, the process is benign, probably non-neoplastic, and easily cured by bilateral tonsillectomy.