Search PubMed⌕ Search

Biomedical subjects

A Sampedro

Publications and source records attributed to A Sampedro.

At least 37 records · Page 2Linked to original sources
PubMed1996

Identification of serum and urine proteins responsible for enhanced pigment production by group B streptococci as amylases.

The serum and urine proteins responsible for enhanced pigment production in Streptococcus agalactiae in culture media were purified by chromatography and were identified as amylases by comparison of their amino acid composition with that calculated for proteins with known sequences. Similar pigment-enhancing activity was displayed by other amylases of nonanimal origin and by maltooligosaccharides.

Amylases↗
PubMed1996

Prognostic value of DNA image cytometry in colorectal carcinoma.

OBJECTIVE: To investigate the diagnostic sensitivity and prognosis predicting of DNA image cytometry in colorectal carcinoma. STUDY DESIGN: We studied the ploidy status and other DNA cytometric parameters in 68 patients with colorectal carcinoma. In addition, clinical-histologic and follow-up information was collected for at least five years. RESULTS: DNA histograms were available in all cases, showing a diploid DNA distribution pattern in 6 (8.8%), tetraploid in 21 (30.9%), hyperdiploid in 20 (29.4%) and hypertetraploid in 21 (30.9%). The differences in the correlation study between cytometric parameters and pathologic features were not statistically significant. Ploidy status and DNA malignancy grade were individually related to five-year survival (P < .005 and P < .05). CONCLUSION: The data show that DNA image cytometry can provide valuable prognostic information on colorectal carcinomas and may prove useful in guiding adjuvant therapy in these patients.

Adenocarcinoma↗
PubMed1996

Comparative flow cytometric analysis of DNA-bound PCNA and DNA content as estimators of S-phase cells in cell cultures.

Flow cytometric estimations of S-phase cells were carried out on cultures from three different cell lines and in frozen aliquots. A PCNA-extraction protocol was applied. Measurements of the S fraction estimated from bivariate PCNA/DNA analysis after detergent extraction of DNA non-bound PCNA were compared with those obtained from total DNA histograms (Vindelöv and Christensen's technique, methanol-fixed whole cells and PCNA-extracted nuclei). No significant differences between methods, or between fresh and frozen specimens, were found in the measurements of the percentage of S-phase cells. Nevertheless, nuclei yield following PCNA extraction was highly variable, ranging from 63% to 10% (mean: 26%). In some cases, the extraction was not complete and samples had to be discarded. Usually, boundaries between S-phase events and G0/G1 or G2/M subpopulations were not clearly defined. Because of these shortcomings, and the fact that is more costly and time consuming, the estimation of the S-phase fraction by means of bivariate DNA-bound PCNA/total DNA flow cytometric studies does not seem to surpass that obtained from standard DNA cell cycle analyses.

Animals↗
PubMed1996

Disappearance of DNA HPV in sequential specimens of occult cervical infection in a "normal" population.

OBJECTIVE: The behaviour of occult infection in the uterine cervix was studied over one year in 175 women randomly selected, to determine if the infection persisted, disappeared or if the viral genotype became modified. STUDY DESIGN: An earlier study of the prevalence of HPV cervical infection detected 11 (6.2%) occult infections. Of these the infectious genotype could only be identified in five. One year later the infected women were subjected to further colposcopical examination and molecular hybridization testing. RESULTS: In seven of the 11 cases with cervical occult infection, the DNA HPV genome was found to be completely absent at year-end. Colposcopic and cytological studies remained negative in all women. CONCLUSIONS: The loss of DNA HPV in seven of the 11 previously positive women is probably due to variability in the number of cells that became infected in a situation where small numbers of copies are made. The high proportion of occult infection with uncharacterized viruses supports the view that this type of infection is often due to new genotypes, presently non-classifiable.

Adolescent↗
PubMed1995

Ploidy analysis on Wilms' tumour touch imprints using ethidium bromide and automated image analysis integrated confocal laser scanning microscopy.

Although image analysis (IA) is increasingly being used to quantitate nuclear DNA, comparative data between fluorescence methods of IA and flow cytometry (FCM) is limited. In this study fluorescence IA was compared with FCM data in a series of Wilms' tumour touch preparations. Airdried touch imprints that had previously been Giemsa stained were restained with ethidium bromide. Confocal fluorescence images were obtained with a confocal laser scanning microscope and assessed by a fully automated IA package. Data was collected from 400 nuclei per imprint. The resulting DNA histograms were analysed and ploidy status and DNA indices determined using standard criteria. Results were compared with those derived from FCM analysis of nuclear suspensions. Ten of twelve tumours were concordant by both techniques. However in two cases assessed as diploid by FCM, IA identified aneuploidy. Excellent correlation between DNA indices as assessed by both techniques was observed (r = 0.987). In the three cases for which both unstained and Giemsa stained touch imprints were available for IA, the histogram configurations did not differ significantly. Fluorescence IA is an accurate and sensitive technique for DNA quantitation, which appears at least comparable to FCM assessment and which has a number of important advantages.

Child, Preschool↗
PubMed1995

Influence of the culture medium on the expression of surface polypeptides of Yersinia enterocolitica.

Three polypeptides (200, 46, and 25 kDal) encoded by the virulence plasmid were detected by SDS-PAGE in the outer membrane of Yersinia enterocolitica 09 grown at 37 degrees C in brain-heart infusion medium. Bacteria grown at the same temperature in the tissue culture medium RPMI 1640 expressed five additional polypeptides (170, 135, 118, 100, and 98 kDal), but the 25-kDal band was not seen. The protein profile in RPMI 1640 resembles the expression pattern displayed by yersiniae when grown in vivo. The immunoblot of total membrane proteins of bacteria grown in brain-heart infusion medium revealed eight plasmid-encoded polypeptides, four of which were also in the outer membrane preparations, including a 28-kDal polypeptide. These peptides do not coincide with known plasmid-encoded outer membrane proteins.

Bacterial Outer Membrane Proteins↗
PubMed1995

Trans-European medical education: experience of the Faculty of Medicine of Oviedo.

The European Community has played a key role in organizing student mobility programmes and in emphasizing the need for a European medical culture. The need for a common core of medical principles and efforts to strengthen inter-European cooperation nurture the philosophy of these exchanges. The Faculty of Medicine of Oviedo has been working on student mobility programmes for the last 7 years. As a result of this activity, about four hundred medical students have participated in various exchanges. This experience is highly positive both for the students and for the institutions taking part in it. The students have the chance to become acquainted with a different country, language, culture and medical training system. Meanwhile, the institutions benefit from their students' experience as well as having the opportunity of starting further cooperative programmes.

Education, Medical, Undergraduate↗
PubMed1995

Modification of immune response in mice by ciprofloxacin.

Some studies have suggested that the addition of ciprofloxacin to in vitro cultures of mitogen-stimulated lymphocytes exerts inhibitory effects on cell cycle progression and immunoglobulin (Ig) secretion. We tested the effects of this drug on some immunity parameters in BALB/c mice. Mice treated intraperitoneally with ciprofloxacin (10 mg/kg of body weight per day) for 3 consecutive days and immunized with sheep erythrocytes 24 h after the last injection showed significant suppression of hemolytic IgG-forming cells, whereas the response of IgM-forming cells remained unchanged. When treatment lasted 7 days the response of antibody-forming cells was not modified. When the 3-day treatment was started at 24 h after immunization with sheep erythrocytes, the response of IgM-forming cells was increased, whereas the response of IgG-forming cells was suppressed. Delayed-type hypersensitivity to sheep erythrocytes was significantly suppressed in animals that received the 3-day treatment with ciprofloxacin and were immunized subcutaneously 24 h after the last injection. In vitro proliferation of lymphocytes from ciprofloxacin-treated mice in response to either lipopolysaccharide or concanavalin A was also suppressed. Leukopenia and an increase in the level of granulocyte-macrophage colony-forming cells in bone marrow were also observed in ciprofloxacin-treated mice. These results, together with those from other reports, suggest that modification of the biological responses by ciprofloxacin is a complex phenomenon that may be influenced by several factors.

Animals↗
PubMed1995

Postgraduate training program for the diagnosis and follow-up of cancer: experience of the University of Oviedo, Spain.

In anticipation of the expected worldwide increase in cancer deaths, the University of Oviedo in 1987 launched a two-year-long doctorate program entitled "Training Programme for the Diagnosis and Follow up of Cancer." The course was organized in three modules, General Basis, Methods, and Applications. Doctoral candidates acquired experience in these areas by means of theoretical lessons, practical work, and seminars with required preparation of special projects. From 1987 to 1990, 30 doctoral candidates completed the program. Some developed impressive projects and doctoral theses on aspects of cancer in the course of the program, which was offered twice, in 1987-88 and in 1988-89.

Aftercare↗
PubMed1994

Chromosome-mediated resistance of Yersinia enterocolitica serotype O9 to intracellular killing by mouse peritoneal macrophages.

The survival of Yersinia enterocolitica serotype O9 within mouse peritoneal macrophages was investigated. To evaluate the role of the virulence plasmid in the resistance to intracellular killing, an isogenic pair of virulent (plasmid-bearing) and avirulent (plasmid-less) O9 strains was used. The virulent strain was able to express plasmid-encoded outer membrane proteins and to colonize the Peyer's patches of orally infected mice. When mice were infected intraperitoneally, both strains were recovered at similar rates and over the same time from the peritoneal cavity. When in vitro assays were performed, both strains showed similar resistance to intracellular killing by monolayers of resident and inflammatory peritoneal macrophages. Previous opsonization of bacteria did not modify their survival within macrophage monolayers. We concluded that serotype O9 strains display a chromosome-mediated resistance to intracellular killing by mouse peritoneal macrophages. Moreover, macrophage resistance does not seem to be of importance for virulence of serotype O9 strains in mice.

Animals↗
PubMed1994

Quantitative pathology of the intraepithelial laryngeal neoplasia.

A clinical-histologic and morphometric study on 32 patients with precancerous laryngeal lesions was carried out. Two biopsies taken at different times were studied, and the cases in which carcinoma developed were compared with those cases in which it did not. The only clinical-histologic variable with prognostic value, related with evolution to carcinoma, was severe dysplasia. The Malignancy Grading System, which grouped together 13 clinical-histologic variables, had both high sensitivity and high specificity. On the other hand, quantitative microscopy was a more sensitive and objective method. Through the relationship between the parameters of orientation/nuclearity and Histometric Progression Index, we could separate those cases in which invasive carcinoma developed from those cases in which it did not with a sensitivity of 100% and a specificity of 82%.

Adult↗
PubMed1993

Quantitative pathology of the cervical intraepithelial neoplasia.

The objective of this study was to determine the efficiency of quantitative microscopy as a method of estimating the progressive cervical intraepithelial neoplasia (CIN). The research design consisted of an analytical study of cases and controls. The study took place in the Pathology Services of 4 hospitals in our region and the Image Processing and Cytometry Service of the university. Two subsequent cervical biopsies taken more than six months apart belonging to 42 patients diagnosed for CIN were studied. As a reference, 20 normal biopsies were taken. Quantitative Microscopy by Digital Image Processing was applied to each one of the three epithelial layers. Cellular orientation, shape factor, perimeter, area and nuclear diameter were taken as maturative markers and the cellularity as a marker of proliferative change. The cellularity in the middle layer of the epithelium allowed us to distinguish patients with CIN (22.9 +/- 6.9) from normal cases (4.6 +/- 2.3) in 93% of the cases. According to this variable in the middle and superficial layers, in 95.2% of the cases 4 new groups were automatically defined. The shape factor of the cells in the superficial cell layer enabled us, although with low sensitivity (45.45%), to predict evolution towards cancer in 65.5% of the cases. In conclusion the validity of Quantitative Microscopy as an objective marker of structural change in the CIN was verified although its value as a predictive marker of evolution is low.

Female↗
PubMed1993

[Generalized lymphadenopathy with morphologic findings of multicentric angiofollicular ganglionic hyperplasia in a patient with AIDS].

We report a case of a 33-year-old man, intravenous drugs abuser, HIV-positive, with peripheral lymphadenopathy, hepato-splenomegaly and fever, in which a ganglionic biopsy showed a histology with morphologic features of multicentric Castleman's-like disease, and minute foci of Kaposi's sarcoma ganglion, without cutaneous lesions. Given the interrelationships between this morphology of angiofollicular lymph node hyperplasia, the development of Kaposi's Sarcoma, and the aggressive clinical course seen in our patient and those in the literature, the use of lymph node biopsy may be an important prognostic tool for the patients with the acquired immunodeficiency syndrome.

AIDS-Related Complex↗
PubMed1992

Yersinia enterocolitica serotype 0:3-induced arthritis in mice: microbiological and histopathological information.

Gross anatomical and histopathological changes in arthritic joints resulting from oral challenge with Yersinia enterocolitica serotype 0:3, upon pretreatment with desferrioxamine, were always more severe than those induced by intravenous infection of immunized animals. In all the acute inflammation episodes studied, live Yersiniae were isolated from the arthritic region. Invariably, a heavy mixed infiltration of synovia, joint spaces and soft tissues was observed at this stage. Concurrent fibrous thickening and vascular proliferation, along with erosion of articular cartilages and anomalous bone regeneration, were also apparent. In spite of these significant facts, the bacterium could be histopathologically identified only in bone marrow where it developed microcolonies and caused significant necrosis as well. The live bacterium was also retrieved from two- and six-month-old arthritic ankles/paws examined, but it could not be seen in histological sections of joints. By this time, no cellular infiltration was evident, but there was extensive fibrosis. Bones were at times greatly enlarged, showing a spongeous-like structure. Additionally, articular cartilages could be completely lost and were substituted by an anomalous ossification filling the joint spaces. This situation led to bone fusion, resembling articular ankylosing traits. In summary, we present the first experimental evidence that Y. enterocolitica serotype 0:3 is a causal agent of osteoarthritis and osteomyelitis, and that it may survive for prolonged periods of time in osseous structures.

Animals↗
PubMed1990

Yersinia enterocolitica serotype O:3 is arthritogenic for mice.

It is shown, for the first time, that Yersinia enterocolitica serotype O:3 is experimentally arthritogenic. Moreover, it is arthritogenic for the mouse, an optimal model for human yersiniosis. This arthritis can be induced by the oral route, the most common route in man. The pattern of joint disease closely parallels that of human reactive arthritis associated with this pathogen.

Animals↗