Genotypic and phenotypic diversity in Enterococcus faecalis: is agar invasion a pathogenicity score?

OBJECTIVES: The main objective of the present study is to analyze different genotypic and phenotypic traits related to virulence in Enterococcus faecalis, as well as evaluated the agar invasion phenotype in a collection of isolates with different clinical origins. MATERIAL AND METHODS: Seventy-nine E. faecalis isolates, with invasive and non-invasive clinical origins, have been used in this work. Presence of cytolysin activator (cylA), gelatinase (gelE), surface protein (esp), aggregation substance (asa1), endocarditis antigen (efaA), and collagen-binding protein (ace) have been analyzed by PCR. Phenotypic characterization included gelatinase activity, haemolysin production, biofilm formation and agar invasion. RESULTS: All the isolates tested harboured at least one of the virulence determinants. The 95.5% of isolates from haematologic samples were positive for agar invasion test, significantly higher than isolates from non-invasive diseases. A significant reduction in relative invasion area was observed in three selected agar-invasive strains after 15 serial passages. CONCLUSIONS: It has been observed a significant high prevalence of agar-invasion positive isolates among strains belonged to haematological samples. Agar invasiveness is reduced after adaptation of clinical isolates to laboratory conditions, showing that agar invasion phenotype can be modulate by culture conditions as other virulence factors observed in different bacterial species.

Evolving architectural patterns in microbial colonies development.

Semithin sections of colonies of three ATCC strains (Staphylococcus aureus, Escherichia coli, and Candida albicans) showed that their internal structure had specific patterns that evolved over the time. These patterns generally were defined by the presence of different layers composed of microorganisms with variable population densities and dead cells. The observed structures in this study could be explained as a particular form of biofilm with an air-semisolid interface.

[Splanchnic remodeling secondary to experimental prehepatic portal hypertension]. / Remodelación esplácnica secundaria a hipertensión portal prehepática experimental.

OBJECTIVE: Portal hypertension as an inducer of intestinal inflammatory response would cause epithelial and splanchnic vascular remodeling in the long-term. This experimental study was carried out to verify this hypothesis. METHOD: Structural alterations characteristic of intestinal epithelial and mesenteric vascular remodeling, the density of goblet cells and the diameter of mesenteric vein branches were studied, respectively, in rats with partial portal vein ligation in the short (1 month) and long-term (1 year). RESULTS: Hyperplasia of goblet cells in the small intestine (duodenum, jejunum, ileum) is maximum after 1 year of evolution of the portal hypertension and is associated with dilatation of the distal branches (3rd and 4th order) of the superior mesenteric vein. CONCLUSION: Long-term splanchnic remodeling in experimental portal hypertension suggests the existence of a chronic inflammatory process in this clinical condition.

Remodelación esplácnica secundaria e hipertensión portal prehepática experimental / Splanchnic remodeling secondary to experimental prehepatic portal hipertensión

Objetivo: La hipertensión portal, en tanto que inductora de una respuesta inflamatoria intestinal, causaría a largo plazo remodelación epitelial y vascular esplácnicas. Con el objeto de verificar esta hipótesis se ha realizado éste trabajo experimental. Método: Se han estudiado como alteraciones estructurales propias de remodelación epitelial intestinal y vascular mesentérica la densidad de células caliciformes y el diámetro de las ramas de la vena mesentérica, respectivamente, en ratas con ligadura parcial de la vena porta a corto (1 mes) y largo (1 año) plazo. Resultados: La hiperplasia de células caliciforrnes en intestino delgado es máxima al año de evolución de la hipertensión portal y se asocia con dilatación de las ramas distales (3er y 4° orden) de la vena mesentérica superior. Conclusión: La remodelación esplácnica que ocurre a largo plazo en la hipertensión portal experimental sugiere la existencia de un proceso inflamatorio crónico en ésta patología

Objective: Portal hypertension as an inducer of intestinal inflammatory response would cause epithelial and splanchnic vascular remodeling in the long-termo This experimental study was carried out to verify this hypothesis. Method: Structural alterations characteristic of intestinal epithelial and mesenteric vascular remodeling, the density of goblet cells and the diameter of mesenteric vein branches were studied, respectively, in rats with partial portal vein ligation in the short (1 month) and long-term (1 year ). Results: Hyperplasia of goblet cells in the small intestine (duodenum, jejunum, ileum) is maximum after I year of evolution ofthe portal hypertension and is associated with dilatation of the distal branches (3rd and 4th order) of the superior mesenteric vein. Conclusion: Long-term splanchnic remodeling in experimental portal hypertension suggests the existence of a chronic inflammatory process in this clinical condition

Ultrastructural localization of Ani s 1, a major allergen from the fish parasite Anisakis simplex.

No data about the nature or function of the first major Anisakis simplex allergen, named Ani s 1, is available. The aim of this study was to investigate the ultrastructural localization of this protein, to obtain further information about it. Ani s 1 was detected in secretory granules of the excretory gland and occasionally lining the main excretory canal. Our results suggest that Ani s 1 could be a secretory product and could have an enzymatic function related to mechanisms of infection.

[Primary effusion lymphoma associated with type-8 human herpes virus infection]. / Linfoma primario de cavidades asociado a infección por herpes virus humano tipo 8.

Primary Effusion Lymphoma is an unusual entity and it has been described as a subset associated with human herpes virus 8 infection in homosexual males with AIDS. Its inclusion as a new entity in the Revised European-American Lymphoma Classification has been recommended. The case in which it is presented is a 47-year-old man, diagnosed with AIDS two years ago, who came with Kaposi's sarcoma. Nowadays, he has a right pleural effusion and a thoracentesis has been carried out. We obtain 10 ml of haemorrhagic fluid which is processed by standard methods. The morphologic study reveals a non-Hodgkin's lymphoma of high-grade. The immunophenotypic study shows a lymphoid neoplasm of indeterminate lineage and high proliferation index. It confirms the HHV-8 in the neoplastic cells by PCR. The diagnosis is a non-Hodgkin's lymphoma of high-grade compatible with Primary Effusion Lymphoma.

Linfoma primario de cavidades asociado a infección por herpes virus humano tipo 8 / Primary effusion lymphoma associated with human herpes virus 8 infection

El linfoma primario de cavidades es una rara entidad, habiéndose descrito un subgrupo asociado a infección por HHV-8 en varones homosexuales con Sida, recomendándose su inclusión como una nueva entidad en la Clasificación Revisada Europea-Americana de los Linfomas. El caso que se presenta es el de un varón de 47 años, diagnosticado de Sida hace dos, que debutó con sarcoma de Kaposi. En la actualidad, se presenta con un derrame pleural derecho y se realiza toracocentesis. Se obtienen 10ml de un líquido hemorrágico, que se procesa de forma rutinaria. El estudio morfológico revela un linfoma no Hodgkin de alto grado. El estudio inmunofenotípico pone de manifiesto una neoplasia de estirpe linfoide, de línea indeterminada y de alto índice proliferativo. Se confirma la infección por HHV-8 en las células neoplásicas, mediante PCR. El diagnóstico es linfoma no Hodgkin de alto grado compatible con linfoma primario de cavidades (AU)

[Primary cavity-based lymphoma and HIV infection]. / Linfoma primario de cavidades e infección por VIH.

BACKGROUND: Primary cavity-based lymphomas (PCBL) represent and uncommon group on non-Hodgkin lymphomas associated with AIDS. They present as malignant effusions with no bone marrow or lymph node involvement, although some cases with bone marrow infiltration at advanced stages have been reported. Tumoral cells are monoclonal and are occasionally infected with human herpesvirus type-8 (HHV-8). PATIENTS AND METHODS: The clinical and evolutive characteristics of six HIV-positive patients with PCBL were analysed. In three of them the presence of genetic sequences of HHV-8 in peripheral blood lymphocytes and lymphomatous effusions was investigated by PCR. RESULTS: The mean age of patients was 37 years and 5 were males. The only female patient had been drug abuser, four males were homosexuals and the other promiscuous heterosexual. The mean CD4+ lymphocyte count was 84 x 10(6)/l (range: 20-180) and all of them had been diagnosed of AIDS. The presentation forms were as pericardial effusion in one case, pleural effusion in three and tumoral ascites in two. Two of the male patients had also Kaposi sarcoma (KS). At diagnosis none of them had infiltration of the bone marrow nor lymphadenopathy. Most malignant cells had immunoblastic traits. The effusions had the characteristics of an exudate and the mean value of lactate dehydrogenase (LDH) was 5,255 IU/l (range: 1,500-11,483). In the three cases investigated there was HHV-8 DNA in the lymphocytes present in the lymphomatous effusion and in peripheral blood. The mean survival after diagnosis was 89 days (7-240). The female patient died without therapy seven days after admission and the five male patients were treated with chemotherapy with a poor response. CONCLUSIONS: HIV-related PCBL associated or not with KA appear in severely immunodepressed patients, their behaviour is very aggressive and its clinical course fatal in a short period of time. The are often associated with KS and HHV-8 seems to be the involved causative agent.

Synaptic immunolocalization of glyoxylate-complex molecules in the striate areas of the rat cerebral cortex: light and electron microscopic studies.

The location of glyoxylate-complex molecules has been investigated in several areas of the rat cerebral cortex using the immunohistochemical peroxidase-antiperoxidase (PAP) method. Antibodies against glyoxylate-complex molecules have been developed in the rabbit after immunization with a glyoxylate-bovine serum albumin conjugate. Observations carried out with the light microscope demonstrated positive immunostaining at the membrane level of scattered neurons located in all cortical areas, mainly in cortical layer IV. The striate areas (17, 18, 18a) had both the greatest number of immunopositive neurons and the most intense ones. At the electron microscopic level, it was observed that in the striate areas an immunopositive reaction was located mainly in the periphery of synaptic vesicles of some nerve endings, and in both pre- and postsynaptic membranes of these synaptic structures. The presence of glyoxylic acid and glyoxylate-complex molecules in such areas leads us to suggest that these substances could play an important role in selected synaptic contacts in which some pyramidal and non-pyramidal neurons are involved.

[Study of histoenzymatic activity of isocitrate-DH in the hepatic tissue of rats treated with AZT: image analysis]. / Estudio de la actividad histoenzimática isocitrato-DH en tejido hepático de ratas tratadas con AZT mediante análisis de imagen.

OBJECTIVE: Recently has been described alterations in different organs of HIV + patients treated with zidovudine (AZT), as secondary effect from drug administration. METHOD: We have developed and experimental rat model, in which the rats were administered AZT in drinking water and we have analysed the activity of enzyme isocitrate DH, of Krebs cycle, in hepatic tissue sections. Histological technique were employed and image analysis to objectivate the results. RESULTS: A significant statistic decrease of the enzyme activity in those animals treated with AZT were observed, compared with the control groups. CONCLUSIONS: The modification from enzyme activities related with Krebs cycle can be traduced in mitochondrial alterations, that could have direct or indirect influence in the appearance of some associated pathologies to the AZT treatment.

[Imaging analysis by computer tomography in chronic middle ear otitis diagnosis]. / Análisis de imagen en el diagnóstico de la otitis media crónica por tomografía computadorizada.

The resource to an image analyzer of coronal plates resulting from computer tomography (CT) of temporal bones suffering chronic otorrhea (tympanosclerosis and cholesteatoma) and its comparison with other plates of normal subjects, allowed the AA. to settle different clear cut densitometric profiles. Hereby a first attempt of objective assessment of radiological images of these pathologies could be contemplated.

Histochemical and ultrastructural changes induced by zidovudine in mitochondria of rat cardiac muscle.

Zidovudine (azidothymidine, AZT), a drug used in acquired immune deficiency syndrome (AIDS), blocks reverse transcriptase and therefore inhibits human immunodeficiency virus (HIV) replication. We carried out an ultrastructural and histoenzymatic study in rat cardiac muscle. Groups of animals (3 rats per group) were given drinking water with or without AZT (1 or 2 mg AZT/ml). After 30, 60 and 120 days, the hearts were studied by light and electron microscopy. Histochemical analysis of isocitrate, succinic, malic, NADH and NADPH dehydrogenase activities revealed no changes in AZT-treated rats compared with control rats. The ultrastructural study showed a disruption of cristae and an increased size of mitochondria in rats treated with AZT for 30- and 60-days. No alterations were observed in rats that received the 120-day treatment. A statistical analysis based on electron micrographs demonstrated a time-dependent ratio between intact and disrupted mitochondria. Rats that received AZT for 30 days showed a higher number of abnormal mitochondria than rats that received the 60 day treatment. No differences with respect to rat controls were observed in the rats that received AZT for 120 days. We conclude that AZT-induced ultrastructural alterations in cardiac muscle did not modify the histochemical activity of several mitochondrial enzymes.