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Biomedical subjects

E Sanchez

Publications and source records attributed to E Sanchez.

At least 37 records · Page 2Linked to original sources
PubMed1999

Prostate specific antigen variation in patients without clinically evident prostate cancer.

PURPOSE: We address long-term within individual variation of serum prostate specific antigen (PSA) in men without clinical or biopsy evidence of prostate cancer. MATERIALS AND METHODS: We studied 943 men from a prostate cancer screening program with 2 PSA (PSA1 and PSA2) measurements available. A third PSA (PSA3) was obtained from 571 men. Only participants with no clinical evidence of cancer were included in the study. Within individual PSA variability was calculated based on indexes of percent coefficient of variation, ratio difference and PSA velocity. The relationship among these indexes, interval between measurements and number of PSA samples was assessed. RESULTS: Mean interval was 670.4 days between PSA1 and PSA2, and 801.8 days between PSA2 and PSA3 (p<0.001). Mean coefficient of variation was 18% after 2 and 15.7% after 3 PSA measurements. Mean ratio differences were -0.047 ng./ml. for 2 and 0.033 ng./ml. for 3 samples. Mean PSA velocity was -0.128 ng./ml. per year for 2 and -0.055 ng./ml. per year for 3 samples, with 95% confidence intervals of 0.634 and 0.315, respectively. Variability was higher if only 2 PSA measurements were done (p<0.001). No clear relationship was found between individual variability and interval between measurements. CONCLUSIONS: PSA velocity is within normal limits in almost all men (more than 95%) without clinically relevant prostate cancer. PSA individual variability is not fully dependent on the time between measurements when intervals are long, and can be substantially decreased with a third PSA sample.

Aged↗
PubMed1998

Fuzzy logic and inflammatory protein variations.

This tutorial style paper has been written for physicians and biologists who are not necessarily familiar with fuzzy set theory and biomedical applications. The field is introduced in the framework of medical diagnosis problems and illustrated with an application to inflammatory protein variations. The model is of special interest in the processing of borderline cases, allowing a graded assignment of diagnoses to patients. Relationships between signs and diagnoses are interpreted as labels of fuzzy sets and it is shown how diagnoses can be derived from soft matching processes. In cases of poor diagnostic classification, appropriate weights are introduced, acting on characterizations of signs, in order to decrease their relative influence. As a consequence, when pattern matching is achieved, the final ranking of inflammatory syndromes assigned to a given patient might change to better fit the actual classification.

Acute-Phase Proteins↗
PubMed1998

Erythrocyte promotion of platelet reactivity decreases the effectiveness of aspirin as an antithrombotic therapeutic modality: the effect of low-dose aspirin is less than optimal in patients with vascular disease due to prothrombotic effects of erythrocytes on platelet reactivity.

BACKGROUND: Aspirin (acetylsalicylic acid, ASA) is widely used for secondary prevention of ischemic vascular events, although its protection only occurs in 25% of patients. We previously demonstrated that platelet reactivity is enhanced by a prothrombotic effect of erythrocytes in a thromboxane-independent manner. This diminishes the antithrombotic therapeutic potential of ASA. Recent data from our laboratory indicate that the prothrombotic effect of erythrocytes also contains an ASA-sensitive component. In accordance with this observation, intermittent treatment with high-dose ASA reduced the prothrombotic effects of erythrocytes ex vivo in healthy volunteers. In the present study, the effects of platelet-erythrocyte interactions were evaluated ex vivo in 82 patients with vascular disease: 62 patients with ischemic heart disease treated with 200 mg ASA/d and 20 patients with ischemic stroke treated with 300 mg ASA/d. METHODS AND RESULTS: Platelet activation (release reaction) and platelet recruitment (fluid-phase proaggregatory activity of cell-free releasates from activated platelets) were assessed after collagen stimulation (1 microg/mL) of platelets, platelet-erythrocyte mixtures, or whole blood. Platelet thromboxane A2 synthesis was inhibited by >94% by ASA administration in all patients. Importantly, platelet recruitment followed one of three distinct patterns. In group A (n=32; 39%), platelet recruitment was blocked by ASA both in the presence and absence of erythrocytes. In group B (n=37; 45%), recruitment was abolished when platelets were evaluated alone but continued in the presence of erythrocytes, indicating a suboptimal effect of ASA on erythrocytes of this patient group. In group C (n= 13; 16%), detectable recruitment in stimulated platelets alone persisted and was markedly enhanced by the presence of erythrocytes. CONCLUSIONS: In two thirds of a group of patients with vascular disease, 200 to 300 mg ASA was insufficient to block platelet reactivity in the presence of erythrocytes despite abolishing thromboxane A2 synthesis. Platelet activation in the presence of erythrocytes can induce the release reaction and generate biologically active products that recruit additional platelets into a developing thrombus. Insufficient blockade of this proaggregatory property of erythrocytes can lead to development of additional ischemic complications.

Adult↗
PubMed1998

The Nuclear Receptor Resource: a growing family.

Last year, the original Glucocorticoid Receptor Resource was expanded into a comprehensive project: the Nuclear Receptor Resource (NRR, http:// nrr.georgetown.edu/nrr/nrr.html ). The NRR has since been offering comprehensive information on nuclear receptor structure and function, as well as general facts of interest to the scientific community on meetings, funding and employment opportunities. The project now includes individual resources as part of a network which integrates information on glucocorticoid, androgen, mineralocorticoid, thyroid hormone, Vitamin D and peroxisome-proliferator activated receptors. Many investigators have joined the NRR network by filling the Who is who? form available in the NRR home page. This has facilitated communication among scientists in the field and dissemination of data nor otherwise published. Because several investigators have contacted NRR authors over the past few months asking for advice and materials for educational purposes, we have recently decided to include in our project an educational resource on nuclear receptors termed the 'Graphics Library'. The input and suggestions of NRR users do shape the future direction of the project, so we encourage user to give us feedback.

Computer Communication Networks↗
PubMed1998

[Surgery of strabismus and rupture of the blood-aqueous barrier (ischemia of the anterior segment)].

BACKGROUND: First described in 1957, anterior segment ischemia (ASI) following extraocular muscle surgery for non paralytic or paralytic strabismus is a rare but serious complication. Systemic and anatomical risk factors can be identified and vesselsparing surgical techniques used. The aim of this study is to evaluate those changes in the anterior chamber that may indicate the presence of post-operative subclinical ASI. METHODS: Pre- and 1 day post-operative anterior chamber flare measurements with the Laser flare cell meter (Kowa FC-1000) were made in 107 patients (109 operations) undergoing strabismus surgery. Surgery was carried out by the same surgeon in all cases and under general anaesthesia. Patients were divided into different groups according to the muscles operated (horizontal recti, vertical recti, obliques, or combinations thereof). RESULTS: Global and selective analysis showed no significant statistical difference between pre- and post-operative flare measurements in patients undergoing strabismus surgery. CONCLUSION: No subclinical ASI was found in this study of 109 strabismus operations (107 patients).

Adolescent↗
PubMed1998

A randomised trial of mode of delivery in women infected with the human immunodeficiency virus.

OBJECTIVE: During the pilot phase of a trial to evaluate the effectiveness of caesarean section delivery compared with vaginal delivery in reducing mother-to-child transmission of human immunodeficiency virus (HIV) infection, the feasibility of randomisation to mode of delivery was assessed. DESIGN: At 36 weeks of pregnancy, women infected with HIV were randomly allocated to either caesarean section delivery at 38 weeks or vaginal delivery. Information was also collected on the reasons why women were not enrolled, either because they refused or had a contraindication. SETTING: Fifty-one centres in six European countries. POPULATION: Pregnant women with confirmed HIV-1 infection. MAIN OUTCOME MEASURES: Randomisation. RESULTS: Three-hundred and thirty-nine women had been randomised by the end of 1996, the large majority from Italy (n = 250) and France (n = 54), with 22 from South Africa, three from Sweden, nine from Barcelona and one from London. A further 150 women were eligible but had not been randomised. Forty-eight women (14%) were not delivered according to the arm to which they were randomised; the majority (n = 44) were changed from vaginal to caesarean section delivery. There is wide variation between European countries in the acceptability and adherence to the mode of delivery trial. CONCLUSION: The pilot phase of this trial has shown that in some settings randomisation to mode of delivery is feasible and acceptable, but that in other settings clinicians and pregnant women are more reluctant to be randomised. Pending further information on transmission rates and accrual, enrollment into the trial continues.

Cesarean Section↗
PubMed1998

Clinical outcome in diffuse large B-cell lymphoma is dependent on the relationship between different cell-cycle regulator proteins.

PURPOSE: The goal of this work was to perform a comprehensive exploration of the relationship between the clinical outcome of diffuse large B-cell lymphoma (DLBCL) and the expression of a panel of tumor suppressor and oncogenic proteins, which includes some cell-cycle regulator proteins involved in the p53 pathway. PATIENTS AND METHODS: To this end, we collected the clinical data of 141 patients with DLBCL and immunohistochemically analyzed diagnostic tumoral tissue from each patient for the presence of Ki67 (MIB1, Immuno-tech, Marseille, France), bcl2, p53, p21/WAF1, MDM2, and retinoblastoma (Rb) proteins. RESULTS: The results show that several proteins are associated with some of the clinical traits analyzed. Multivariate analysis showed that an extended overall survival (OS) time was associated with low growth fraction, high Rb protein, and low MDM2 expression, as well as with known clinical parameters. The probability of inducing a complete remission (CR) was only associated with clinical parameters, although univariate study showed that a low growth fraction was associated with a higher probability of inducing a CR. Univariate study of disease-free survival (DFS) showed that tumors with high bcl2 expression and nodal origin have a shorter DFS time, although multivariate study only confirmed the adverse effect of bcl2 expression. CONCLUSION: Taking all these results into consideration, it seems that although the overall outcome for patients with DLBCL is decided by a combination of different clinical and biologic variables, the expression of some of these cell-cycle regulator proteins appears to be specifically associated with the different clinical features of tumors.

Adolescent↗
PubMed1998

Man-vector contact of phlebotomine sand flies (Diptera: Psychodidae) in north-central Venezuela as assessed by blood meal identification using dot-ELISA.

Human bait is traditionally used to assess man-vector contact, which is a key point in the study of the epidemiology of vector-borne diseases. However, in highly endemic foci, where this method should be avoided, this information could be obtained by blood meal analysis of engorged insects. In the village El Ingenio, Miranda State, Venezuela, Lutzomyia ovallesi and Lutzomyia gomezi are vectors of cutaneous leishmaniasis (CL). From June 1994 to March 1995, sand flies were collected inside houses on 974 CDC trap nights from 1900 to 0700 h. A total of 7,281 female sand flies were caught: 68.7% of them were identified as L. ovallesi, and 3.3% were identified as L. gomezi. Almost all of the blood-engorged flies (233 of 237) were dissected and identified, and gut contents were examined by dot enzyme-linked immunosorbant assay (dot-ELISA) using antisera against humans and common household animals including the domestic mouse. The Human Blood Index was 0.817 for L. ovallesi. These results suggest that intradomiciliary transmission may occur and account for the cases of CL frequently observed in newborn children in El Ingenio.

Animals↗
PubMed1997

The Nuclear Receptor Resource Project.

We have expanded the original Glucocorticoid Receptor Resource (GRR) database to include several individual resources as part of a larger project called the Nuclear Receptor Resource (NRR). In addition to the GRR, the NRR currently features the Thyroid Hormone Receptor Resource, the Androgen Receptor Resource, the Mineralocorticoid Receptor Resource, the Vitamin D Receptor Resource, and the Steroid Receptor Associated Proteins Resource. The goal of the NRR project is to provide a comprehensive resource for information on the nuclear receptor superfamily, and to provide a forum for the dissemination and discussion of both published and unpublished material on these proteins. Although the individual resources are managed from different servers, all the files are integrated and can be accessed through the project's Home Page, housed at http://nrr. georgetown.edu/nrr.html. In the near future, we hope to expand the project to contain information on other nuclear receptors and to better our electronic publication system. To accomplish this, we encourage the involvement of nuclear receptor investigators in the NRR.

Amino Acid Sequence↗
PubMed1997

Influence of individual aggressiveness on the dynamics of competitive populations.

Two populations are subdivided into two categories of individuals (hawks and lows). Individuals fight to have access to a resource which is necessary for their survival. Conflicts occur between individuals belonging to the same population and to different populations. We investigate the long term effects of the conflicts on the stability of the community. The model is a set of ODE's with four variables corresponding to hawk and dove individuals of the two populations. Two time scales are considered. A fast time scale is used to describe frequent encounters and fightings between individuals trying to monopolize the resource. A slow time scale is used for the demography and the long term effects of encounters. We use aggregation methods in order to reduce this model into a system of two ODE's only for the total densities of the two populations which is found to be a classical Lotka-Volterra competition model. We study different cases of proportions of hawks and doves in both populations on the global coexistence and the mutual exclusion of the two populations. Pure dove tactics in both populations are unstable. In cases of mixed hawk and dove in both populations, there is coexistence. Pure dove or mixed hawk-dove tactics in one population can coexist with pure hawks in the other one when the costs of fightings between hawks are large enough.

Aggression↗
PubMed1997

[Comparative results of deep sclerectomy transformed to trabeculectomy and classical trabeculectomy].

OBJECTIVE: To study the learning risk of a new surgical technique, the deep sclerectomy (DS), which may be complicated with a perforation of the trabeculodescemetic membrane. To do so, we compared the results and the complications of patients who underwent DS transformed in trabeculectomy (DSt) and those of patients who underwent trabeculectomy (TE). MATERIALS AND METHODS: Between june 1994 and june 1996, we performed 234 DS, 19 of them had to be transformed into a TE, because of a perforation of the trabeculodescemetic membrane during the deep sclerocorneal dissection. Two matched groups of patients were prospectively followed, one group including 19 DSt and a control group including 19 TE. RESULTS: The IOP decrease on the first postoperative day was greater in the DSt-group compared to the TE-group (2.32 +/- 3.89 vs 6.73 +/- 4.31, p = 0.004). Scleral perforations occurred mainly during the learning phase of this new surgical technique. Postoperative complications were similar in both groups, except for hypotony and hyphema which were more frequent in the DSt-group (hypotony: 90% vs 37%, p = 0.0019; hyphema: 68% vs 16%, p = 0.017). The long term success rate with or without medication were comparable in both groups. CONCLUSION: This study shows that, when a DS is complicated with a perforation of the trabeculodescemetic membrane, the long term success rate of the surgery is similar to that of trabeculectomy. However, immediate postoperative complications such as hypotony and hyphema are increased. These results should encourage surgeons to learn this new non perforating filtration surgery.

Aged↗
PubMed1997

[Ocular phenotype in a child with chondrodysplasia punctata, rhizomelic form].

Chondrodysplasia calcificans punctata (CDP) is a rare congenital syndrome characterized by calcific stippling of the hyaline cartilage. CDP is classified into 4 types: the autosomal dominant Conradi-Hünermann type, the autosomal recessive rhizomelic type, the X-linked dominant form and the X-linked recessive form. We present a child affected with a rhizomelic CDP born from consanguinous parents. The ocular phenotype consisted of microphakia associated with a progressive bilateral "cataracta cortico-zonularis suturata". At 11 years of age, a phacoemulsification and intraocular lens implantation was performed in the left eye.

Cataract↗
PubMed1997

Changes in water activity and some microbial groups during storage of pet feed.

The effect of exposure of different pet feed samples to the typical temperature and moisture conditions of many months of the year (9 degrees C and 80% RH) on water activity (aw), pH and growth of various microbial groups (mesophilic aerobic bacteria, fungi and yeasts) was studied. The storage conditions were found to scarcely influence the samples pH, with no significant changes relative to the initial values (the standard deviation was 0.04 and the coefficient of variation 0.85%). By effect of exposure to the temperature and moisture conditions tested, the initially stable feeds reached moisture contents close to 20% and aw values near those of equilibrium with the ambient relative humidity during storage. Microbial counts increased with increasing aw, with final means of 8.44, 9.16 and 8.71 log CFU/g for mesophilic aerobic bacteria, fungi and yeasts, respectively. The risk of mycotoxin production at these aw values is discussed. Careful control of moisture is recommended in order to preserve the quality of pet feed throughout its scheduled shelf life.

Animal Feed↗
PubMed1996

Evaluation of the first 50 ACR360 acrylic intraocular lens implantations.

PURPOSE: To evaluate the clinical results of implantation of the ACR360 soft acrylic intraocular lens (IOL). SETTING: Civico Hospital, Lugano, Switzerland. METHODS: This prospective, medium-term study comprised the first 50 consecutive patients who had small incision scleral tunnel phacoemulsification and implantation of an ACR360 acrylic IOL (loptex/Allergan). Intraoperative and postoperative complications, best corrected visual acuity (BCVA), intraocular pressure (IOP), preoperative and postoperative astigmatism, and IOL centration were recorded. Mean follow-up was 12 months +/- 3 (SD). RESULTS: One day postoperatively, 94% of best cases (n = 46) achieved a BCVA of 20/40 or better and 54%, 20/25 or better. At 2 weeks, 98% had 20/40 or better and 78%, 20/25 or better. After 6 months, all patients achieved a BCVA of 20/40 or better and 83%, 20/25 or better. No statistically significant changes in keratometric astigmatism or IOP occurred. CONCLUSIONS: The ACR360 IOL gave clinical results comparable to those of other foldable lenses; however, it can also be implanted in cases of intraoperative capsular complications and in eyes with intravitreal silicone oil. Development of an injecting system for implantation and substituting the polypropylene loops with poly(methyl methacrylate) haptics could improve lens quality.

Acrylates↗
PubMed1996

Cytomegalovirus preemptive therapy with ganciclovir in renal transplant patients treated with OKT3.

In an attempt to decrease the prevalence and severity of cytomegalovirus (CMV) disease, preemptive therapy with ganciclovir was administered to all renal transplant patients treated with OKT3 between February 1993 and December 1994 (26 patients). The results were compared with those of a historical group treated with OKT3 but not with ganciclovir (29 patients). Both groups were similar in age, sex, number of previous transplants, number of rejections, serological status of donor and recipient and OKT3 dose. Ganciclovir was administered during the period of treatment with OKT3. Only 2 (7.7%) treated patients developed CMV disease versus 11 (37.9%) of the control group (p = 0.01). In the control group the intensity of the disease was severe in 7 (63.6%) cases, whereas in the treated patients it was always of slight intensity (p = 0.01). In conclusion, preemptive therapy with ganciclovir during treatment with OKT3 decreases the prevalence and severity of CMV disease.

Acyclovir↗
PubMed1996

Coexistence of diffuse plane normolipaemic xanthoma and amyloidosis in a patient with monoclonal gammopathy.

Diffuse plane normolipaemic xanthomatosis (DPNX) is a well-defined clinicopathological entity that characteristically presents with yellow-orange plaques in the periorbital areas, the neck, the upper trunk and the flexural folds. DPNX has been reported in association with lymphoproliferative disorders and, occasionally, with miscellaneous, probably coincidental disorders. A case of DPNX in a patient with an IgG lambda monoclonal gammopathy and systemic amyloidosis is reported. Clinical and histopathological findings revealed typical features of DPNX and amyloidosis coexisting in the cutaneous lesions. To our knowledge this is the first reported case showing coexistence of xanthoma and amyloidosis in cutaneous lesions in a patient with a monoclonal gammopathy.

Aged↗
PubMed1995

Decontaminating dental instruments: testing the effectiveness of selected methods.

The decontamination of dental instruments before sterilization is designed to safeguard dental personnel from exposure to bloodborne pathogens and to remove gross contamination. The authors studied the relative effectiveness of decontamination methods that included ultrasonic cleaning, presoaking with an enzymatic cleaner and dishwashing. Results indicated that the most effective methods involved presoaking followed by cleaning. However, no single procedure eliminated detectable concentrations of blood contamination.

Analysis of Variance↗