Biomedical subjects

M Urrutia

Publications and source records attributed to M Urrutia.

At least 19 recordsLinked to original sources

PubMed2002

[Effectivity versus toxicity of minoxidil as antiproliferative agent for lens epithelial cells. In vitro study].

PURPOSE: To evaluate the inhibitory effect of minoxidil on cultured proliferating lens epithelial cells (LECs) versus cytotoxic effect over corneal endothelial cells in culture, because minimum side effects over anterior chamber structures and particularly on corneal endothelium are required for successful therapy and prevention of posterior capsular opacification (PCO). METHODS: New Zealand Rabbit LECs and corneal endothelium were cultured in DMEM at 35 degrees C in 5% CO2 in multiwells during 7 days. Both types of cells were exposed to minoxidil (1, 2 and 4 mM) for 1 and 24 hours. Control group and balanced salt solution group were included. After seven days multiwells were processed for light microscopy study. Morphometric study of cellular population of LECs and corneal endothelium cells were done using a computed planimetry system. RESULTS: Dose-dependent effect on LECs proliferation was noted and non-confluent colonies of cells were observed on all treated groups. Morphologic changes in normal appearance of corneal endothelial cells after 1 hour of minoxidil treatment was observed and intracellular alterations were confirmed even with the lowest dose exposure. CONCLUSIONS: Although effectiveness of minoxidil suppressing in vitro LECs proliferation could be suggest as a useful therapeutic agent to prevent PCO, however the inhibitory effect of different concentrations on corneal endothelial cells conditioned its possible use on ocular surgery.

Animals↗

PubMed2001

Diagnostic performance of the urinary bladder carcinoma antigen ELISA test and multiparametric DNA/cytokeratin flow cytometry in urine voided samples from patients with bladder carcinoma.

BACKGROUND: The objective of the current study was to comparatively analyze the sensitivity and specificity of flow cytometric DNA/cytokeratin 8/18 measurements and the urinary bladder carcinoma antigen (UBC) enzyme linked immunoabsorbent assay (ELISA) test for the detection of bladder carcinoma in voided urine samples. METHODS: Eighty-one fresh urine voided samples, preserved frozen for a maximum period of 3 months, belonging to patients with an active bladder carcinoma (n = 37), patients who were free of disease as confirmed by cystoscopy (n = 19), patients receiving intravesical therapy (n = 17), and individuals with other benign and malignant conditions (n = 8), were collected. Flow cytometry measurements of thawed samples were based on the detection of cytokeratin (CK) 8+ and CK18+ cells using the 3F3 and 6D7 monoclonal antibodies alone or in combination with the measurement of cell DNA contents, after propidium iodide staining. Urinary bladder carcinoma antigen test was measured by ELISA. RESULTS: Patients were grouped according to the presence (n = 44) or absence (n = 29) of bladder carcinoma as confirmed by cystoscopy, and taking cutoffs of 9.7 microg/L for UBC-ELISA, 75% for the percentage of 3F3 (+) and 6D7 (+) cells, and 10.6% for the proportion of hyperdiplod cells that suggested a specificity of 83%, the individual sensitivity obtained for each parameter was 77%, 5%, 9%, and 77%, respectively. The presence of DNA aneuploid populations showed a relatively low sensitivity (36%) although it was the most specific parameter (93%). Combining UBC antigen test with the proportion of cells showing DNA content higher than 2n increased to 89% the sensitivity of the UBC antigen alone. However, false-positive results for both techniques were found in individuals with urologic diseases other than bladder carcinoma and in patients receiving intravesical therapy. CONCLUSIONS: The authors' results suggest that the combined use of the UBC antigen test and DNA/cytokeratin flow cytometry double stainings for the analysis of freshly obtained urine voided samples, cryopreserved to assure cellular integrity, is of great clinical utility for the detection of tumor recurrence in patients with bladder carcinoma.

Aged↗

PubMed2001

Utility of serial urinary tumor markers to individualize intervals between cystoscopies in the monitoring of patients with bladder carcinoma.

BACKGROUND: Cross-section studies have shown the diagnostic characteristics of certain urinary tumor markers for the detection of bladder carcinoma. However, the role of serial urinary tumor markers in the monitoring of patients with bladder carcinoma in daily clinical surveillance has not been completely defined yet. METHODS: The study comprised 1185 urine samples belonging to 232 patients with a previous bladder carcinoma: 106 patients under follow-up (Group 1) and 126 bladder carcinoma patients receiving intravesic instillations (Group 2). Patients were monitored with urinary tumor markers during a one-year follow-up period. Urine samples were collected before cystoscopies and in the intercystoscopic periods for patients in Group 1 and before intravesic instillations for patients Group 2. Urinary bladder carcinoma antigen (UBC), CYFRA 21-1 and nuclear matrix proteins (NMP22) were measured by immunoassays. RESULTS: Monitoring of the disease with urinary tumor markers could detect recurrence sooner than scheduled cystoscopies in 27 patients (87%) for UBC, 27 patients (87%) for CYFRA 21-1, and 26 patients (84%) for NMP22 out of 31 Group 1 patients who recurred; and in 16 patients (67%) for UBC, 17 patients (71%) for cytokeratin fragments (CYFRA) 21-1, and 13 patients (54%) for NMP22 out of 24 Group 2 patients who recurred. The most relevant finding was that persistence of negative urinary markers during follow-up was largely indicative of disease free status in 65 of 75 (87%) patients of Group 1 and 31 of 102 (30%) cases of Group 2. Although false positive results were present, they were mainly associated with sporadic urinary tract infections in 10 of 75 (13%) cases of Group 1 and in 36 of 102 (35%) patients of Group 2; and with urine samples collected in the first two months at the beginning of intravesic therapy in 35 of 102 patients (34%) in Group 2. CONCLUSIONS: Monitoring of bladder carcinoma patients with serial urinary tumor markers could anticipate detection of recurrence. Persistent negative results might postpone and reduce the number of cystoscopies. Once the limitations leading to false positive results are controlled by urinalysis and by starting sample collection when basal levels are reached in patients with intravesic therapy, urinary tumor markers might eventually individualize the intervals between cystoscopies in the surveillance of patients with bladder carcinoma.

Antigens, Neoplasm↗

PubMed2001

Comparative predictive values of urinary cytology, urinary bladder cancer antigen, CYFRA 21-1 and NMP22 for evaluating symptomatic patients at risk for bladder cancer.

PURPOSE: We study the potential diagnostic use of urinary bladder cancer antigen, CYFRA 21-1 and NMP22*; for evaluating symptomatic patients who present with microscopic hematuria and are at risk for bladder cancer. MATERIALS AND METHODS: Urinary tumor markers were determined in 187 samples from 112 patients symptomatic of bladder cancer (group 1), and 75 with benign and other urological conditions (group 2). Immunoassays were used to measure the 3 selected biomarkers. Sensitivity and specificity were established by previously defined cut points. Biomarker results were reported as corrected and uncorrected for urinary creatinine. Urinalysis was performed in all samples. RESULTS: Positive and negative predictive values were 85.5%, 80.5% and 81.1%, and 80.8%, 79.2% and 76.5% for urinary bladder cancer antigen, CYFRA 21-1 and NMP22, with the cutoffs 9.7 microg./l., 5.4 microg./l and 10.0 units per ml., respectively. These predictives values were 85.2% and 72.5%, respectively, for urinary cytology. The combination of biomarkers decreased the positive predictive values to 72.3% to 78.6% and increased negative predictive values to 84.2% to 86.1%. Urinary tract infection, inflammation and malignancy associated with other genitourinary organs were the primary cause for false-positive test results in the 3 assays evaluated. CONCLUSIONS: With a single biomarker, around 80% of the positive results would have correctly identified symptomatic patients for cystoscopy. Of the negative results 75% would have correctly reduced the number of cystoscopies. Sensitivity and negative predictive values could be improved with the combination of biomarkers but with a loss of specificity and positive predictive values. Urinary tract inflammation and other genitourinary malignancies might contribute to the reduction in specificity of these tests.

Adult↗

PubMed2000

Estimation of the hydrophobic effect in an antigen-antibody protein-protein interface.

Antigen-antibody complexes provide useful models for analyzing the thermodynamics of protein-protein association reactions. We have employed site-directed mutagenesis, X-ray crystallography, and isothermal titration calorimetry to investigate the role of hydrophobic interactions in stabilizing the complex between the Fv fragment of the anti-hen egg white lysozyme (HEL) antibody D1.3 and HEL. Crystal structures of six FvD1.3-HEL mutant complexes in which an interface tryptophan residue (V(L)W92) has been replaced by residues with smaller side chains (alanine, serine, valine, aspartate, histidine, and phenylalanine) were determined to resolutions between 1.75 and 2.00 A. In the wild-type complex, V(L)W92 occupies a large hydrophobic pocket on the surface of HEL and constitutes an energetic "hot spot" for antigen binding. The losses in apolar buried surface area in the mutant complexes, relative to wild-type, range from 25 (V(L)F92) to 115 A(2) (V(L)A92), with no significant shifts in the positions of protein atoms at the mutation site for any of the complexes except V(L)A92, where there is a peptide flip. The affinities of the mutant Fv fragments for HEL are 10-100-fold lower than that of the original antibody. Formation of all six mutant complexes is marked by a decrease in binding enthalpy that exceeds the decrease in binding free energy, such that the loss in enthalpy is partly offset by a compensating gain in entropy. No correlation was observed between decreases in apolar, polar, or aggregate (sum of the apolar and polar) buried surface area in the V(L)92 mutant series and changes in the enthalpy of formation. Conversely, there exist linear correlations between losses of apolar buried surface and decreases in binding free energy (R(2) = 0.937) as well as increases in the solvent portion of the entropy of binding (R(2) = 0.909). The correlation between binding free energy and apolar buried surface area corresponds to 21 cal mol(-1) A(-2) (1 cal = 4.185 J) for the effective hydrophobicity at the V(L)92 mutation site. Furthermore, the slope of the line defined by the correlation between changes in binding free energy and solvent entropy approaches unity, demonstrating that the exclusion of solvent from the binding interface is the predominant energetic factor in the formation of this protein complex. Our estimate of the hydrophobic contribution to binding at site V(L)92 in the D1.3-HEL interface is consistent with values for the hydrophobic effect derived from classical hydrocarbon solubility models. We also show how residue V(L)W92 can contribute significantly less to stabilization when buried in a more polar pocket, illustrating the dependence of the hydrophobic effect on local environment at different sites in a protein-protein interface.

Animals↗

PubMed2000

The complex dynamic network of microtubule and microfilament cytasters of the leech zygote.

The organization of the cytoskeleton in the early first interphase zygote and its involvement in organelle redistribution were studied in the glossiphoniid leech Theromyzon trizonare by confocal and electron microscopy, immunofluorescence, and time-lapse video imaging after microinjection of labeled tubulin and/or actin and loading with a mitotracker. The cytoskeleton consists of an inner or endoplasmic and an outer or ectoplasmic domain. The inner domain consists of a monaster whose fibers retract from the zygote periphery by the end of the early first interphase. The outer domain is built upon a network of microtubules and microfilaments cytasters. Short pulses of microinjected labeled actin or tubulin and Taxol treatment demonstrate that cytasters are centers of microtubule and microfilament nucleation. Immunostaining with anti-centrophilin, anti-BX-63, and anti-AH-6 indicates that the network of cytasters includes centrosomal antigens. Cytasters move in an orderly fashion at speeds of 0.5-2 micrometer/min, in an energy-dependent process retarded and finally blocked by the ATP analogue AMP-PNP and high concentrations of Taxol. Colliding cytasters fuse and form larger cytoskeletal nucleation centers. The leech zygote is a highly compartmentalized cell whose cytasters function as articulated components of a very dynamic cytoskeletal system engaged in bulk transportation of organelles during ooplasmic segregation.

Actin Cytoskeleton↗

PubMed2000

[Cytokeratins (UBC and CYFRA 21-1) and nuclear matrix proteins (NMP22) as urine tumor markers in the diagnosis of bladder cancer].

BACKGROUND: The development of urinary tumor markers such as UBC, CYFRA 21-1 and NMP22 appeared to be non invasive alternative methods for the detection of bladder cancer. We compared the individual and combined sensitivity of the urinary tumor markers in the detection of bladder cancer, contrasting them with the conventional diagnostic procedures. PATIENTS AND METHODS: 237 voided urines from subjects under risk for bladder cancer were collected immediately before the endoscopic examinations: 44 patients under suspicion of a primary bladder tumor and 193 patients under follow-up of a previous bladder cancer were included. UBC and NMP22 were measured by enzyme-immunoabsorbent-assays and CYFRA 21-1 by an electro-chemiluminescense-immunoassay. RESULTS: Taking the cutoffs of 9.7 micrograms/l for UBC, 5.4 ng/ml for CYFRA 21-1 and 10.0 U/ml for NMP22 sensitivities were 70%, 69% and 67% for UBC, CYFRA 21-1 and NMP22 at specificities of 95%, 94% y 80%, respectively. All tumor markers showed higher sensitivities than urinary cytology (7%), microhematuria (62%) and gross hematuria (10%) at specificities of 99%, 78% and 99%, respectively. The combinations of NMP22 plus CYFRA 21-1 reached the highest sensitivity (79%), slightly lower than simultaneously measuring the three tumor markers (80%). CONCLUSIONS: The sensitivities of the urinary markers UBC, CYFRA 21-1 and NMP22 appeared to be high enough so as to substitute urinary cytology. The diagnostic similarity between cytokeratins individually and in each type of patients might not recommend their simultaneous determination. The combined measurement of NMP22 and one cytokeratin marker (CYFRA 21-1 or UBC) appeared to be the most recommended.

Adult↗

PubMed2000

Urinary tissue polypeptide-specific antigen for the diagnosis of bladder cancer.

OBJECTIVES: To evaluate the diagnostic characteristics of the urinary measurement of cytokeratin tissue polypeptide-specific antigen (TPS) for the detection of bladder cancer. METHODS: Three hundred thirty-five individuals in five groups were studied: group 1, subjects with microhematuria under suspicion for primary bladder cancer; group 2, patients being followed up with scheduled cystoscopic examinations; group 3, patients in follow-up receiving chemotherapy instillations; group 4, patients with other urologic diseases; and group 5, healthy subjects. Urine samples belonging to subjects from groups 1, 2, and 3 were collected immediately before cystoscopy. Additionally, patients from groups 2 and 3 were monitored with urinary TPS for a minimum period between two cystoscopies. TPS was measured by an enzyme immunosorbent assay. RESULTS: Receiver operating characteristic analysis gave a sensitivity of 64% and a specificity of 84% at a threshold value of 279 U/L. The positive and negative predictive value was 66% and 82%, respectively; accuracy was 77%. TPS could discriminate the presence of bladder tumor sooner than the scheduled cystoscopies in 9 of 19 follow-up patients with recurrence. False-positive results during follow-up were found in 112 urine samples, one third of which were associated with urinary tract infections. TPS did not appear to be specific for bladder cancer, with elevated results in 45% of patients from group 4, which might lead to clinical misinterpretation of urinary TPS results. CONCLUSIONS: Urinary TPS might provide additional information for the detection of bladder cancer as an adjunct to cystoscopy. Considering the false-positive rates, different urologic diseases should be ruled out before making clinical decisions on the basis of elevated urinary TPS results.

Administration, Intravesical↗

PubMed2000

Evaluation of two new urinary tumor markers: bladder tumor fibronectin and cytokeratin 18 for the diagnosis of bladder cancer.

Our objectives were to evaluate the diagnostic value of two new urinary tumor markers, cytokeratin 18 (CK18) and bladder tumor fibronectin (BTF), for the detection and monitoring of bladder cancer. The study comprised 931 urine samples belonging to 402 subjects: 112 individuals under suspicion for a primary bladder tumor (group 1); 104 bladder cancer patients under scheduled follow-up (group 2); 109 bladder cancer patients receiving intravesical instillations (group 3); 45 patients with other urological diseases (group 4); and 32 healthy subjects (group 5). Voided urine samples were collected before cystoscopies, between them and before intravesical instillations. CK18 and BTF tests were measured by chemiluminescent immunoassays. Optimal receiver operating characteristic cutoffs of 7.4 microg/L for CK18 and 52.8 microg/liter for BTF rendered overall sensitivities of 66.2% for CK18 and 80.0% for BTF at specificities of 88.4 and 74.7%, respectively. Urinary cytology provided a sensitivity of 29.2% at a specificity of 99.1%. Sensitivities were 80.8, 74.2, and 82.3% for BTF and 71.1, 77.4, and 64.7% for CK18 for groups 1 to 3, respectively. False positive rates were higher for BTF in all groups of patients. Elevated urinary tumor markers during the monitoring of patients with bladder cancer could detect recurrence sooner than scheduled cystoscopies. Persistence of negative markers was greatly indicative of free of disease status in follow-up. CK18 and BTF in urine may eventually prove to be of benefit for specific patients with bladder carcinoma given its higher sensitivity compared with cytology. In selected patients, namely those with persistent negative urinary CK18 and BTF, the number of cystoscopies could be reduced.

Adult↗

PubMed1996

Cystic masses of the spleen: radiologic-pathologic correlation.

Many focal splenic lesions may appear to be cystic at cross-sectional imaging. In this article, the following types of cystic splenic masses are discussed: congenital (true cyst), inflammatory (abscesses, hydatid cyst), vascular (infarction, peliosis), posttraumatic (hematoma, false cyst), and neoplastic (hemangioma, lymphangioma, lymphoma, metastasis). The key findings at ultrasound, computed tomography, and magnetic resonance imaging can be correlated with underlying gross and microscopic pathologic findings. Although tissue sampling is still required in many cases to yield a definitive diagnosis, recognition and understanding of the spectrum of imaging and pathologic features of these lesions often help narrow the differential diagnosis.

Cysts↗

PubMed1994

[Duplex sonography in the diagnosis of deep venous thrombosis in the lower limbs].

Duplex ultrasonography (DUS) has shown high sensitivity and specificity in the diagnosis of proximal deep vein thrombosis (DVT). It is now considered the initial procedure of choice for the evaluation of this entity because of its advantages (low cost, non invasiveness, no need for contrast media, no ionizing radiation) and because of the possibility of making other diagnoses, v.g. Baker's cyst. With the development of color Doppler, this study has become easier and now includes the calf and iliac vessels. Nevertheless, it has not improved the sensitivity and specificity of DUS. Phlebography, until now the "golden standard", has become a "second choice" procedure for proximal DVT but it continues to be of value in the evaluation of calf veins, which are more difficult to evaluate with DUS, and other venous pathology.

Adolescent↗

PubMed1994

[Adverse reactions to high osmolarity contrast media. A comparative-prospective study].

The purpose of this study was to verify and compare the different types of reactions to iodinated contrast media available at the Social Security Metropolitan Hospital Complex: Conray 60%, Vascoray and Uromiron. These are ionic, high osmolality compounds. The authors found that, in 400 patients not only the osmolality had an important role in the reactions observed, but that the intrinsic nature of the molecule of the contrast medium used was the determining factor.

Adolescent↗

PubMed1994

[Solid and papillary epithelial neoplasm of the pancreas. Report of 2 cases].

Solid and papillary epithelial tumor of the pancreas occurs mainly in young women and its main characteristic is the appearance of an abdominal mass which progressively increases in size. The radiologic, surgical and pathological correlation shows that it is a tumor of low grade malignancy with a favorable prognosis, after therapy and according to the location of the tumor. The authors report the clinical history of the first two confirmed cases of this entity in Panama, which occurred in 1985 and 1992, respectively, in women less than 25 years of age.

Adult↗

PubMed1993

[The sonographic diagnosis of hypertrophic stenosis of the pylorus].

The clinical records of 18 children were studied, between 15 and 60 days old. They were hospitalized due to vomiting and diagnosis of suspected pyloric hypertrophic stenosis (PHS). The sonography confirmed the diagnosis in 8 children, by the thickening of the muscular layer and enlargement of the pyloric canal. The surgery (pyloromyotomy) ratified the diagnosis in all 8 children. They all were in good health after being operated.

Female↗

PubMed1993

[The sonographic diagnosis of hypertrophic stenosis of the pylorus].

Female↗

PubMed1992

Geochemical prospection of cadmium in a high incidence area of prostate cancer, Sierra de Gata, Salamanca, Spain.

A high incidence of prostate cancer was observed in some areas of Salamanca province, Spain. After excluding the most common etiological factors as the cause, it is concluded that the only possible risk factor must be due to the presence of some environmental carcinogen. In view of the etiological relationship between Cd and the pathological state, a study was carried out on the geochemistry of this element in the area. Anomalous amounts of Cd were found in stream sediments. This anomaly does not correspond to human activity, but rather to high regional amounts of cadmium in the substrate. Thus, the contents of Cd in soils developed over substrates containing naturally-occurring anomalous amounts of cadmium and the concentration in underground waters should be considered as a risk factor in this area.

Cadmium↗

PubMed1990

Know well to do good.

Health care should be entrusted to professionals who have received well-rounded training in the humanitarian as well as the technical aspects of such care. Training of this sort is essential for effective resolution of ethical conflicts that arise in professional practice. Starting from that premise, this article examines a number of ethical problems commonly encountered by nurses in the course of their daily work.

Altruism↗

PubMedDate not supplied

Rectal perflubron: new application in MRI of perirectal fistulae.

PURPOSE: Our goal was to determine the efficacy of MRI with rectal administration of perflubron in the evaluation of perirectal and pelvic fistulae, with an emphasis on development of an improved method for fistula visualization. METHOD: Fourteen pelvic and/or perirectal fistulae were evaluated in nine patients with MRI after the rectal administration of 200 ml of perflubron. Images were reviewed by two independent readers and evaluated for the presence or absence of fistulae. Qualitative assessment was also performed, rating the examinations for the ability to visualize the fistulae. Comparison was made with the clinical examination and/or operative findings, as well as available preperflubron imaging studies (CT = 10; fluoroscopy = 1; preperflubron MRI = 4). RESULTS: MRI with rectal perflubron demonstrated all 14 fistulae (100%), while preperflubron imaging demonstrated only 7 of 14 (50%) fistulae (p < or = 0.008, Wilcoxon signed rank test). In addition, MRI with perflubron resulted in significantly improved qualitative visualization of fistulae (overall very good rating versus poor rating for preperflubron imaging, p < or = 0.006, Wilcoxon signed rank test). CONCLUSION: MRI with rectal perflubron is a superior modality for imaging of fistulae, compared with conventional methods, since it allows a noninvasive means of demonstrating the presence of a fistula as well as offers improved qualitative assessment of fistulous disease.

Administration, Rectal↗