[Trident sign in spinal cord neurosarcoidosis]. / Signo del tridente en la neurosarcoidosis medular.

TITLE: Signo del tridente en la neurosarcoidosis medular.

Syncytia Induction by Clinical Isolates of Human Respiratory Syncytial Virus A.

OBJECTIVE: Syncytia formation is the hallmark of the cytopathic effect caused by human respiratory syncytial virus (HRSV), which is the most important viral respiratory pathogen in children. This article reports methodological improvements in primary HRSV isolation and the importance of syncytia formation and mRNA levels of F protein for the progeny yield, using clinical isolates of HRSV. METHODS: The A and B strains of HRSV were isolated in HEp-2 cell cultures from fresh and frozen nasopharyngeal aspirates. The formation of syncytia was evaluated using 2 different assays. Levels of F protein mRNA were quantified by real-time PCR while HRSV progeny titration was done by plaque assay. RESULTS: HRSV was primarily isolated from 238 of 312 (90.7%) samples, and 13 of these (12 HRSV-A and 1 HRSV-B) were continuously passaged in vitro. The quantity and size of syncytia formed by 6 pure HRSV-A clinical isolates were different, as were the levels of F protein mRNA. CONCLUSION: There is a direct correlation of quantities of syncytia and inoculum size, but not with mRNA levels of HRSV-A F protein. Importantly, levels of F protein mRNA were directly related to progeny production.

Morphological and immunohistochemical analysis of the biocompatibility of resin-modified cements.

The aim of this double-blind randomized study was to evaluate the biocompatibility of resin-modified glass ionomer cements (RMGIC) by means of morphological and immunohistochemical analyses. RMGICs were selected and divided into four groups: Group CK (Crosslink Orthodontic Band Cement); Group RS (Resilience Light Cure Band Cement) Group RMO (RMO Band Cement), Group TP (Transbond Plus Light Cure Band), and Group C (Control-polyethylene). The materials were implanted in rat subcutaneous tissues, randomly selected for this study. After time intervals of 7, 15, and 30 days the tissues were submitted to morphological analysis. In immunohistochemical analysis, the immuno-marking of antibody CD68 was evaluated. The results obtained were statistically analyzed by the Kruskal-Wallis and Dunn tests (p < .05). In the morphological analysis after 7 days, Groups RS, RMO and TP showed more intense inflammatory infiltrate (p = .004) and only Group RMO presented greater intensity of multinucleated giant cells (p = .027). In the immunohistochemical analysis, Groups RMO and RS were observed to present a larger quantity of CD68+ (p = .004) in the time interval of 7 days and only Group RMO presented statistically significant difference for this parameter after 15 days (p = .026). In the time interval of 30 days, Group RMO presented the largest quantity of multinucleated giant cells (p < .004). The RMGICS Crosslink and Transbond Plus provided significantly better tissue biocompatibility than the Resilience and RMO Cements.

Invasive cells in the placentome of Andean populations of Mabuya: an endotheliochorial contribution to the placenta?

New world lizards of the genus Mabuya have the most specialized level of placentotrophy among reptiles known to date, and related to that, they have the most complex allantoplacenta characterized by a series of morphological specializations that converge with those known for eutherian mammals. One of these specializations is the placentome that is found in the embryonic pole of the incubation chamber. In the mature allantoplacenta, this structure is morphologically the most complex, which could support an important amount of nutrient exchange between mother and fetus. According to the relationship between the chorioallantois and the syncytial uterine epithelia, the placenta of Mabuya populations shows some interesting similarities to the synepitheliochorial type. Recently, cells of chorionic origin have been found invading the syncytial uterine epithelium, and in very close proximity with uterine blood vessels. In this study, we describe the relationship between these invasive chorionic cells, the uterine syncytium, and the subjacent blood vessels of several populations of this genus, by means of high resolution optical microscopy and transmission electron microscopy. Cell groups originating from the chorion, of variable size and shape, penetrate the uterine syncytial epithelium extending complex cytoplasmic projections that come in contact with uterine capillaries and form an extensive and complex double-membrane system that surrounds the capillary. The close relationship between the chorion and the maternal circulation suggests that the Mabuya placentome shows some characteristics of an endotheliochorial placenta. This finding constitutes so far the only documented example of an endotheliochorial placentation in Reptilia.

Tumor oseo de celulas gigantes (Osteoclastoma) de perone: a propósito de un caso / Giant cell tumor bone (Osteoclastoma) of perone: a purpose of a case

El tumor óseo de células gigantes es generalmente benigno, raro, grande, solitario agresivo localmente; denominado así por las células que lo constituyen las cuales son del tipo de los osteoclastos multinucleados, de ahí su otro nombre osteoclastoma. La experiencia acumulada evidencia que estos afectan en el adulto a la epífisis y metafisis, pero en los adolescentes solo afecta las zonas proximales confinadas por las placas de crecimiento. La mayoría de estos tumores aparecen en la zona periférica de la rodilla en mas de un 50 por ciento de los casos. Se reporta como síntoma mas evidente el dolor periarticular que es el estímulo que lleva a la consulta. Es considerado una neoplasia traicionera ya que histológicamente no hay diferencia entre osteoclastoma benigno y el infrecuente osteoclastoma maligno complicando el tratamiento. Existen características radiológicas que orientan al diagnóstico como la expansión excesiva de la cáscara perióstica a nivel epi-metafisiario; siendo el método gold standard de diagnóstico la RMN, donde podemos diferenciar características macroscópicas especificas del tumor; es importante tener en cuenta el rastro óseo (Survey, gammagrafía), ya que se han reportado casos de tumores multicentricos generalmente entre 2 y 3 focos neoplásicos distintos. Según su patogenia se ha establecido una gradación actual dada por la sinergia clinicoradiopatológica como elemento predictivo pero que no aporta significancia a la hora del tratamiento. Anteriormente se manejaban estas neoplasias conservadoramente, en la actualidad el tratamiento se inclina a la resección total en bloque buscando la curación total con posterior reemplazo con injerto o implante; ya que el tratamiento local mediante curetaje reporta una gran tasa de recidivas alrededor de un 50 por ciento. El uso de radioterapia en esta patología esta proscrito por la prevalencia de degeneración sarcomatosa. Presentación del caso: se presenta el caso de una paciente femenina de 17 años.

Morphology of the rediae of Echinostoma paraensei (Trematoda: Echinostomatidae) from its intermediate host Lymnaea columella (Mollusca, Gastropoda).

The morphology of the rediae of Echinostoma paraensei obtained from Lymnaea columella was studied using light, scanning and transmission electron microscopy. The measurements of the mature rediae differ from those described originally, and the taxonomic importance of the ambulatory buds and papilliform process is discussed. Uniciliated papillae were observed in the mouth region. The birth papilla is a bulb-like structure, well defined at the anterior end of the body of the rediae, which opens through a split. There are no microvilli in the tegument surface of the larvae, but numerous tegumental folds, varying according to the contraction of the body of the rediae. The outer syncytial layer is located on a thick basal lamina below which the circular and the longitudinal muscle fiber layers are located.

Arrested apoptosis without nuclear fragmentation produced by efferent duct ligation in round spermatids and multinucleated giant cells of rat testis.

The apoptotic process evoked by efferent duct ligation in the testes of adult rats was followed for 10 days by differential staining for haematoxylin-eosin, periodic acid-Schiff and a modified trichrome technique in optical microscopy and by ultrastructural localization of acid phosphatase. Round spermatids showed the first effects of efferent duct ligation. At day 3 after ligation, annular clumps of chromatin with typical apoptotic characteristics appeared against the nuclear membrane of these cells. Afterwards, membranous structures and a wide separation between the two layers of the nuclear membrane were observed but nuclear fragmentation did not occur and apoptotic granules were not seen. Cytoplasmic components were also altered, and severely damaged organoids and empty vacuoles lacking acid phosphatase reaction were frequently seen. On day 2 after efferent duct ligation, multinucleated giant cells appeared, which displayed similar characteristics as spermatids and showed no acid phosphatase reaction. Although abnormal spermatids and multinucleated giant cells were surrounded by the cytoplasm of Sertoli cells, neither lysosomal acid phosphatase nor phagocytic activity was detected. It is concluded that efferent duct ligation specifically affects round immature spermatids eliciting a partial nuclear apoptotic response that is not accompanied by autophagic or heterophagic activity and without lysosomal participation in Sertoli cells.

Inflammatory cytokine production by immunological and foreign body multinucleated giant cells.

Multinucleated giant cells (MGC) are a common feature of granulomas. The mechanism of their formation has been studied extensively, but their function has not been completely characterized. A new method for the in vivo production of MGC was developed involving subcutaneous injection of microscopic nitrocellulose particles with adsorbed mycobacterial antigens into the footpads of sensitized BALB/c mice (immune [I]-MGC), or by nitrocellulose administration to non-sensitized mice (foreign body [FB]-MGC). The development of granulomas with a highly enriched MGC population was observed 2 weeks after the nitrocellulose injection. MGC were larger with a greater number of nuclei in I-MGC than in FB-MGC. From days 7-28 after nitrocellulose administration, the production of interleukin-1alpha (IL-1alpha) and tumour necrosis factor-alpha (TNF-alpha) was demonstrated in both MGC types by in situ reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. After 2 months, the MGC had ceased production of IL-1alpha and TNF-alpha, but the expression of transforming growth factor-beta (TGF-beta) was very high, occurring together with extensive fibrosis. These results suggest that MGC are an active source of inflammatory cytokines, which can contribute to the initiation, maintenance and down-regulation of granulomatous inflammation induced by immunological and inert substances.

Angiohistiocitoma com células multinucleadas: relato de caso / Angiohistiocytoma with multinucleate cells: a case report

O angiohistiocitoma com células multinucleadas é dermatose vascular benigna, caracterizada pela presença de múltiplas pápulas eritêmato-violáceas, agrupadas, acometendo preferencialmente alguma extremidade. Sua histologia evidencia hiperplasia vascular com proliferação de células do tecido conjuntivo, associada à presença de células gigantes multinucleadas. Acomete principalmente mulheres após a quarta década de vida. Relata-se o primeiro caso dessa entidade na América Latina e discute-se os principais aspectos clínicos, histopatológicos e imuno-histoquimicos

Sinciciotrofoblasto en placenta de término de octodon degus: estudio ultramicroscópico de transmisión y barrido / Synciciotrophoblast in term placenta of octodon degus: ultramicroscopic study of transmission and scanning

La placenta del degu, roedor autóctono chileno, es de tipo hemocorial, subtipo hemomonocorial. La barrera placentaria es semejante a las zonas alfa de la barrera placentaria humana y está constituida por un sincicio verdadero y continuo, por una membrana basal, escaso tejido conectivo y capilares fetales de tipo continuo y no fenestrados. La subplacenta está constituida por células tipo citotrofoblasto con capacidad mitática. El sincicio falso proviene de diferenciación de células de la subplacenta y diferencia a su vez a sincicio verdadero. Su aspecto citológico es semejante al citotrofoblasto de transición. La subplacenta desaparece al final de la gestación y el sincicio falso diferencia en gran parte a sincicio verdadero. Al final de la gestación la placenta está constituida en gran parte por un sincicio verdadero que asegura y facilita el intercambio metabólico madre-feto y viceversa

Ultrasound characteristics of connective tissue around porous hydroxyapatite hypodermic implants in rats.

Adults Sprague-Dawley rats were implanted with porous hydroxyapatite (Interpore 200), following a procedure different from that of Kawaguchi et al (1992). Instead of implanting hydroxyapatite (Ha) in periodontal osseus defects, we introduced Ha-implants in the hypodermis of rats. Animals were sacrificed on days 30, 90 and 150 (six in each stage). The interface between the Ha and connective tissue was studied by transmission electron microscopy, with the aim of understanding the biocompatibility and mechanisms of union of both parts. The connective tissue reaction to the Ha implant was characterized by fibrovascular proliferation, with abundant fibroblasts, macrophages, multinucleated giant cells, and by the formation of a capsule surrounding the implant. The multinucleated giant cells were observed in the interface along all stages and exhibited: (a) a progressive increase in mitochondria, ribosomes, rough endoplasmic reticulum and vesicles containing particles of Ha; and b) an electronlucent material of variable aspect in vesicles contained in their cytoplasmic expansions. The prominent cytologic aspects of the multinucleated giant cells in the juxta-Ha zone may indicate that both, the biocompatibility and the intimate union between connective tissue and Ha, are strongly dependent on the presence of these cells.

Ultrasound characteristics of connective tissue around porous hydroxyapatite hypodermic implants in rats

Adults Sprague-Dawley rats were implanted with porous hydroxyapatite (Interpore 200), following a procedure different from that of Kawaguchi et al (1992). Instead of implanting hydroxyapatite (Ha) in periodontal osseus defects, we introduced Ha-implants in the hypodermis of rats. Animals were sacrificed on days 30, 90 and 150 (six in each stage). The interface between the Ha and connective tissue was studied by transmission electron microscopy, with the aim of understanding the biocompatibility and mechanisms of union of both parts. The connective tissue reaction to the Ha implant was characterized by fibrovascular proliferation, with abundant fibroblasts, macrophages, multinucleated giant cells, and by the formation of a capsule surrounding the implant. The multinucleated giant cells were observed in the interface along all stages and exhibited: (a) a progressive increase in mitochondria, ribosomes, rough endoplasmic reticulum and vesicles containing particles of Ha; and b) an electronlucent material of variable aspect in vesicles contained in their cytoplasmic expansions. The prominent cytologic aspects of the multinucleated giant cells in the juxta-Ha zone may indicate that both, the biocompatibility and the intimate union between connective tissue and Ha, are strongly dependent on the presence of these cells

Extracellular and intracellular degradation of collagen by trophoblast giant cells in acute fasted mice examined by electron microscopy.

The fine structure of trophoblast giant cells and their interaction with collagen at the antimesometrial region on the 9th day of pregnancy was examined in fed and acute fasted mice. Collagen fibrils and filamentous aggregates (disintegrating collagen fibrils) were observed in the extracellular space. Three types of intracellular vacuoles containing collagen fibrils were present: vacuole type A exhibited typical cross-banded collagen immersed in finely granular electron-translucent material; and vacuoles type B and C showed electron-opaque granular material containing, respectively, faint cross-banded collagen and narrow clear stripes often with faint periodicity. In fed animals vacuoles type B were absent and the others were less evident. Only fasted animals showed extracellular acid phosphatase activity on collagen fibrils, filamentous aggregates and confined regions of the extracellular space. Intracellular acid phosphatase activity was observed in vacuoles type B and in lysosomes. The results indicate that trophoblast giant cells are capable of breaking down extracellular collagen and also of internalizing collagen for intracellular degradation. It is likely that these events are part of the process of invasion of the uterine wall. However, in fasted mice, collagen breakdown is more pronounced, and it may therefore contribute to the provision of amino acids and other nutrients for the undernourished fetus.

Peripheral giant cell granuloma. An immunohistochemical and ultrastructural study.

OBJECTIVE: To study the nature of multinucleated and mononuclear cells from peripheral giant cell granuloma (PGCG). MATERIALS AND METHODS: Formalin-fixed, paraffin-embedded sections of 40 cases of PGCG were immunohistochemically stained for vimentin, alpha I-antichymotrypsin, CD68, S-100 protein, lysozyme, leucocyte common antigen (LCA), factor VIII-related antigen and muscle cell actin. Six cases of PGCG were also studied by transmission electron microscopy. RESULTS: Vimentin, alpha I-antichymotrypsin and CD68 were expressed in both the mononuclear and multinucleated giant cells. Dendritic mononuclear cells, positive for S-100 protein, were noted in 67.5% of the lesions, whereas lysozyme and leucocyte common antigen were detected in occasional mononuclear cells. Ultrastructural examination showed mononuclear cells with signs of phagocytosis and sometimes interdigitations with similar cells. Others presented non-specific characteristics and the third type exhibited cytoplasmic processes and occasional Birbeck granules. Some multinucleated giant cells showed oval nuclei, abundant mitochondria and granular endoplasmic reticulum whereas others presented with irregular nuclei and a great number of cytoplasmic vacuoles. CONCLUSIONS: Immunohistochemical and ultrastructural results suggest that PGCGs of the jaws are composed mainly of cells of the mononuclear phagocyte system and that Langerhans cells are present in two thirds of the lesions.

Atypical stromal giant cells of cervix uteri--evidence of Schwann cell origin.

The report describes atypical multinucleated giant cells adjacent to proliferated nerve fascicles in a circumscribed subepithelial area of the cervix uteri of a 44-year-old multipara. Ultrastructural examination revealed cytoplasmatic processes, basal lamina, intracytoplasmic microfibrils, bizarre nuclear shapes with pseudoinclusions and nuclear fragments connected by small chromatin bridges (nucleotesimals). Immunohistochemical examination showed positive staining for vimentin and S-100 protein. Quantitative topography exhibited an isotropic distribution of the giant cells in an anisotropic architecture of mononuclear cells. A Schwann cell origin of the atypical giant cells is postulated. Aetiopathogenetically the lesion is regarded to be due to a trauma during delivery followed by regenerative proliferation of nerve fascicles and degenerative alterations of proliferating Schwann cells. The knowledge of this lesion is considered important, because the atypical cells could be confounded with malignant neoplastic cells.

Diazepam effect upon the microscopic structure of the mouse placenta.

CD-1 strain, female mice, aged 5 to 7 months, were mated with males of the same age. Females presenting vaginal plug were separated and randomly distributed in two groups to be treated from the 6th to 17th day of gestation. One group received single daily diazepam doses (2.7 mg/kg i.p.), the other, 0.9% saline in equivalent volumes. Females were killed on 18th day, the placentas removed and fixed in 10% formaldehyde, pH 7.3, dehydrated and embedded in paraplast; 3 microns thick sections were stained with hematoxylin-eosin and Weigert hematoxylin and analyzed under light microscopy. Placentas of the diazepam-treated females presented dilated chorion vessels and intervillous spaces. Trophoblastic cell nuclei presented chromatin in coarse granules, atypically distributed in the karyolymph, which had lesser staining affinity. Giant cells showed vacuolized cytoplasm and coarsely granulated chromatin. Results indicate that diazepam causes structural changes, possibly placental and fetal physiology.

[Immaturity of syncytial trophoblast in maternal malnutrition. Ultrastructural analysis]. / Inmadurez del sinciciotrofoblasto en desnutrición materna. Análisis ultraestructural.

We studied the placental membrane at term in normal females and females with malnutrition not related to associated pathologic processes of pregnancy. Both groups belonged in the low socioeconomic stratum. The fetal aspect of placenta from malnourished females showed signs of immaturity in relation to gestational age, as evidenced by transitional cytotrophoblastic cells in different stages of maturation. The latter appear as a third intermediata layer between cytothropoblast and syncitiotrophoblast.