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.

Progressive hepatocytic fatty infiltration in rats with prehepatic portal hypertension.

BACKGROUND/AIMS: Homogenous evolution, with a narrow range of portal hypertension, degree of portosystemic shunt and hepatic atrophy has been described in the experimental model of prehepatic portal hypertension in the rat. However the great differences observed in the rats' liver weight could be attributed to a pathological alteration of the liver. Based on this, we performed an evolutive histological study of the liver. This study shows the existence of a progressive hepatocytic fatty infiltration. METHODOLOGY: Male Wistar rats with portal hypertension induced by triple stenosing ligation of the portal vein at 1 month (group II, n=4) and at 1 year (group IV, n=10) of postoperative evolution were used. The portal pressure, body, liver and splenic weights, types of collateral circulation and degree of mesenteric venous congestion were studied. The intracytoplasmatic lipid microvacuoles were quantified in hepatocytes with an image analyzer (software MIP/CID, Spain). The results were compared with those obtained in control rats with the same evolutive periods (Groups I and III). RESULTS: The hepatic fatty infiltration in Group II (TPVS 1 month) (30.12+/-53.92 micron2) is similar to that presented by Group III (Control 1 year) (16.52+/-45.20 micron2), while there is an increase (p<0.001) in Group IV (triple portal vein stenosis 1 year) (182.03+/-371.42 micron2) in relation to the other groups studied. The progressive hepatic fatty infiltration in triple portal vein stenosis rats is associated with a decrease of portal pressure and of the incidence of liver hepatic atrophy, portosystemic collateral circulation and mesenteric venous congestion. CONCLUSIONS: TPVS produces progressive hepatocytic fatty infiltration in the rat so that this prehepatic portal hypertension experimental model could also be considered as a hepatic steatosis model.

Ki-67 immunolabeling in pre-malignant lesions and carcinoma of the prostate. Histological correlation and prognostic evaluation.

The antigen Ki-67, which is associated with cell proliferation, has been demonstrated to be useful in predicting the development of human tumors. The objective of this study was to evaluate the prognostic utility of this biomarker in pre-malignant and malignant lesions of the prostate. A total of 162 prostate biopsies taken from patients diagnosed for benign prostatic hyperplasia (BPH, n=49), low grade prostatic intraepithelial neoplasia (LGPIN, n=53), high grade prostatic intraepithelial neoplasia (HGPIN, n=25) and carcinoma (CAR, n=35), were studied. Immunohistochemistry for Ki-67 was carried out on all the samples and the number of labeled cells was semi-quantitatively evaluated (weak, moderate or intense). In the non-invasive lesions, the presence of Ki-67-positive cells in the luminal layer of the epithelium was evaluated qualitatively as positive or negative. The correlation between the immunolabeling for Ki-67 and the histological diagnosis showed highly significant differences between BPH and CAR, LGPIN and CAR and HGPIN and CAR, with no significant differences being found among the other groups. Analysis of the immunolabeling in luminal cells of non-invasive lesions showed an increase in accordance with the increase in the degree of histological lesion, the greatest percentage being obtained in the HGPIN lesions (88.0%), with significant differences among all the groups. Bearing in mind that Ki-67 is a prognostic biomarker for cell proliferation, our results demonstrating the immunolabeling of Ki-67 in the luminal compartment of non-invasive lesions having the potential to evolve to malignancy, may have prognostic implications.

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.

Angiomixoma superficial: presentación de un caso / Superficial angiomiyxoma. A case report

El angiomixoma superficial es un tumor mixoide de lento crecimiento, localizado en la dermis profunda y el tejido adiposo subcutáneo, con tendencia a la recidiva pero sin capacidad metastásica. Se presenta el caso debido a su rareza. El estudio anatomopatológico habitual muestra varios nódulos mixoides de escasa a moderada celuaridad con pequeños vasos en su seno. Mediante técnicas inmunohistoquímicas se pone de manifiesto la positividad de las células neoplásicas para vimentina y su negatividad para desmina. a los tres meses de ser resecado, el tumor recidiva, mostrando caracteres similares al primario. La extirpación quirúrgica con márgenes amplios es recomendable para evitar posteriores recidivas (AU)

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.

Comparative study of microbiological and histopathological techniques used for the detection of Helicobacter pylori.

This study evaluates the sensitivity, specificity and predictive values of several techniques commonly used for the detection of Helicobacter pylori in an analysis of 105 biopsy specimens (gastric and duodenal). For comparative purposes, the techniques investigated were divided into 2 groups: histopathological and microbiological. The former included hematoxylin-eosin and Giemsa stains, a Gram stain modified for use in tissue, and immunohistochemical techniques. Microbiological analysis was performed using culture, the urease test and the conventional Gram stain. The immunohistochemical techniques proved to be the most sensitive (93%). The modified Gram stain was sufficiently sensitive (92%) and specific (97%) for the detection of the bacterium. When combined with a microbiological technique such as the urease test, this stain showed increased sensitivity (96%) but its specificity was reduced to 94%. This combination of tests is recommended for the detection of H. pylori in biopsy specimens since it is easily performed at low cost and gives excellent results. For economical reasons, it is suggested that the use of immunohistochemical techniques should be restricted to specific cases.

Simultaneous detection of antigens and specific DNA sequences of human papillomavirus in uterine cervical biopsy specimens. Description of a double-labelling technique.

We studied 70 uterine cervical biopsy specimens with a histological diagnosis compatible with human papillomavirus (HPV) infection. We carried out immunohistochemical and in situ hybridization techniques and selected 22 specimens that had given a positive result with both techniques. We then used a double-labelling technique (a combination of immunohisto-chemistry and in situ hybridization) to detect simultaneously viral antigens and specific gene sequences of HPV. With this technique we found three different cell types in the tissue: (1) cells with black nuclei, positive by immunohisto-chemistry and in situ hybridization; (2) cells with red nuclei, negative by immunohistochemistry and positive by in situ hybridization; and (3) cells with light blue nuclei, negative by both techniques. In this study we describe this technique; and we believe that the simultaneous detection of viral antigens and specific gene sequences of HPV may be very useful in the study of the virus-cell interaction.

Distribution of glyoxylate dehydrogenase activity in cortical and subcortical regions of the rat brain. A light microscopic histoenzymological study.

The distribution of the glyoxylate dehydrogenase (GLYO-DH) (Glyoxylate oxidoreductase) activity has been investigated in rat brain using the corresponding histochemical method. The results have demonstrated a positive histochemical reaction in neurons of several cortical and subcortical areas. These neurons are located in the same regions in which operate monoaminergic neurotransmitters. These facts suggest a possible interaction between glyoxylic acid and monoaminergic neurotransmission.

Labelling pattern obtained by non-isotopic in situ hybridization as a prognostic factor in HPV-associated lesions.

In the study of infection of the lower female genital tract caused by human papillomavirus (HPV), one of the main concerns is the search for prognostic factors to predict the evolution of premalignant low- and high-grade squamous intraepithelial lesions. This study has evaluated the prognostic usefulness of the patterns of positive reaction obtained by non-isotopic in situ hybridization (NISH), referred to as diffuse, punctate, or mixed 'labelling patterns'. The study examined 141 vulvar and uterine cervical biopsy specimens that were positive for HPV by a NISH screening technique and that had the following histological diagnoses: low-grade squamous intraepithelial lesion (LSIL; n = 87); high-grade squamous intraepithelial lesion (HSIL, n = 40); and squamous cell carcinoma (SCC n = 14). Typing of all the specimens was carried out by NISH with DNA probes specific for HPV types 6/11 (low risk), 16/18 (high risk), and 31/33/51 (intermediate risk), and the labelling pattern observed in each specimen was recorded. Statistical analysis of the results showed that there was a significant difference in the distribution of labelling patterns, both by lesion diagnosis (P < or = 0.004) and by infecting viral type (P < or = 10(-6)). Lesions with a punctate or mixed pattern are considered more likely to undergo malignant evolution and consequently have a worse prognosis than lesions with a diffuse pattern.

[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.

Diagnosis of genital infection caused by human papillomavirus using in situ hybridisation: the importance of the size of the biopsy specimen.

AIM: To determine the size of a cervical biopsy specimen with human papillomavirus (HPV) infection required to enable in situ hybridisation to be carried out with a guarantee of a reliable result. METHODS: In situ hybridisation was carried out in 142 cervical uterine biopsy specimens classified histologically as low grade and high grade squamous intraepithelial lesions. Epithelial length at the level of the basal membrane was measured by image analysis. The specimens were divided into 10 groups based on epithelial length. RESULTS: Of the biopsy specimens, 61.2% were HPV positive. In specimens with an epithelial length below 5 mm 31.9% were HPV positive; in those between 5 and 9 mm in length 67.5% were HPV positive; and in those greater than 9 mm in length 81.8% were positive for HPV. For low grade squamous intraepithelial lesions (n = 90), 68.4% of specimens with an epithelial length greater than 5 mm were HPV positive. For high grade squamous intraepithelial lesions (n = 52), 86.8% of specimens with an epithelial length greater than 5 mm were HPV positive. CONCLUSIONS: For a diagnosis of HPV infection using in situ hybridisation, the minimum length of epithelium in a cervical biopsy specimen should be 5 mm. For high grade squamous intraepithelial lesions, specimens over 5 mm in length are suitable. For low grade squamous intraepithelial lesions, to minimise the number of false negative results, the ideal minimum length is 10 mm.

[Image analysis of naso-sinusal pathology with computerized tomography]. / Análisis de imagen en tomografía computadorizada de patología nasosinusal.

Imaging analysis has been applied to study typical cases of nasosinusal diseases, in an attempt to determine its capabilities for CT scan interpretations. Thus, polyps with sinusitis, cerebrospinal fluid occupying sinuses, cysts and bone tumors may be compared in order to obtain objective results that may help in the differential diagnosis in these conditions.

[Vaccine coverage and levels of protection with triple viral vaccine in a children population]. / Cobertura vacunal y niveles de protección frente a la vacuna triple vírica en una población infantil.

The purpose of this study is to know the immunity status of children in 10th area of Madrid and the effectiveness of vaccination campaigns against rubella, mumps and measles. An epidemiological interview together with ELISA have been used to determine the antibodies rates. 87.8%, 77.3% and 69.3% children studied were found to have immunoprotection against this viral infections. These rates are lower than those recommended by WHO; however, by age groups, the study shows statistically significant increase in children aged 5 years or less, what means a progressive acceptance of measles, rubella and mumps vaccination by population.