Search PubMed⌕ Search

Biomedical subjects

C Cortés

Publications and source records attributed to C Cortés.

At least 19 recordsLinked to original sources
PubMed2000

A prospective search for ocular lesions in hospitalized patients with significant bacteremia.

The purpose of this study was to determine the prevalence, risk factors, and prognostic value of ocular lesions in unselected patients with bacteremia. A total of 202 bacteremic patients, 101 nonbacteremic septic patients, and 90 nonseptic control patients were compared in a prospective, controlled, observational study. Ocular lesions related to bacteremia were found in 12% of the bacteremic group, 5% of the septic group, and 2% of the control group. Ocular lesions were significantly more frequent in the bacteremic patients than in the control patients (P=.007). The severity of the clinical condition and the presence of fungemia predict independently a higher risk of ocular lesions. Mortality rates among bacteremic patients with and without ocular lesions were, respectively, 32% and 8% (P<.01; OR, 3.99). The asymptomatic nature of most ocular lesions in patients with bloodstream infections and the impossibility of amelioration in most cases lead us to recommend ophthalmologic examination for bacteremic patients only when prognostic information is needed.

Adolescent↗
PubMed1999

Antiphospholipid antibodies and retinal thrombosis in patients without risk factors: a prospective case-control study.

PURPOSE: To determine the prevalence of antiphospholipid antibodies and other immunologic abnormalities in patients with occlusive retinal vascular events, exempt from conventional risk factors of retinal thrombosis. METHODS: Forty patients with retinal vascular occlusion (26 with retinal vein occlusions, eight with arterial occlusions, two with combined venous and arterial occlusions, and four with venous occlusions plus vasculitis), free of main accepted risk factors for retinal thrombosis, were prospectively screened for antiphospholipid antibodies (anticardiolipin-antibodies and lupus anticoagulant) and other immunologic abnormalities. Fourteen patients were younger than 50 years. Prevalence and mean values of antiphospholipid antibodies (aPL) were compared with those in a homogeneous control group of 40 patients. RESULTS: The prevalence of antiphospholipid antibodies in the study group was 22.5% (nine of 40). Comparison with control group prevalence (5% [two of 40]) showed a statistically significant difference (P = .04). Six patients in the study group disclosed positivity for IgG-anticardiolipin antibodies, one patient for IgM anticardiolipin antibodies, and two patients for both isotypes IgG and IgM anticardiolipin antibodies. The antibody assay for lupus anticoagulant was negative for all patients. Three patients were diagnosed as having primary antiphospholipid antibody syndrome and are undergoing systemic anticoagulant therapy. Relevant immunologic abnormalities were also found (27.5% with antinuclear antibodies, 35% with elevation of circulating immune complexes, 35% with complement deficiency, 30% with positive rheumatoid factor, and 17.5% with positive C-reactive protein). Thirteen patients (32.5%) had more than four parameters altered. No significant association was found between prevalence or mean values of anticardiolipin antibody and patients younger than 50 years. CONCLUSIONS: The high prevalence of anticardiolipin antibodies in patients with vaso-occlusive retinopathy exempt from conventional risk factors, and the relevant diagnostic and therapeutic implications, lead us to recommend a systematic search for specific antiphospholipid antibodies in such patients.

Adult↗
PubMed1999

Role of the Trichoderma harzianum endochitinase gene, ech42, in mycoparasitism.

The role of the Trichoderma harzianum endochitinase (Ech42) in mycoparasitism was studied by genetically manipulating the gene that encodes Ech42, ech42. We constructed several transgenic T. harzianum strains carrying multiple copies of ech42 and the corresponding gene disruptants. The level of extracellular endochitinase activity when T. harzianum was grown under inducing conditions increased up to 42-fold in multicopy strains as compared with the wild type, whereas gene disruptants exhibited practically no activity. The densities of chitin labeling of Rhizoctonia solani cell walls, after interactions with gene disruptants were not statistically significantly different than the density of chitin labeling after interactions with the wild type. Finally, no major differences in the efficacies of the strains generated as biocontrol agents against R. solani or Sclerotium rolfsii were observed in greenhouse experiments.

Blotting, Western↗
PubMed1999

[Preliminary results of horizontal gastroplasty with Roux in Y anastomosis in patients with severe and morbid obesity].

BACKGROUND: Morbidly obese subjects have a high incidence of complications. The poor results of dietary treatments, has prompted the search of new therapies for obesity and among these, surgical procedures. AIM: To report the long term results of horizontal gastroplasty with Roux en Y anastomosis in morbidly obese subjects. PATIENTS AND METHODS: Fifty patients with an initial body mass index of 41.3 +/- 6 kg/m2 have been subjected to a horizontal gastroplasty with Roux en Y anastomosis. During the study period, surgical techniques were modified, reducing the gastric pouch size, adding a truncal vagotomy, cholecystectomy, and increasing the length of the Roux en Y loop from 70 to 100 cm. Twenty five patients have been followed for two years. RESULTS: There was no operative mortality and one patient had an anastomotic leak that required 35 days of hospitalization. During follow up, in one patient, the stapled suture line loosened. After two years of follow up, weight decreased from 112 +/- 19 to 77.2 +/- 14 kg. CONCLUSIONS: Horizontal gastroplasty with Roux en Y anastomosis achieved an adequate weight loss with a low rate of complications in this group of morbidly obese subjects.

Adolescent↗
PubMed1998

Cross-clamping of the three hepatic veins in the piggyback technique is a safe and well tolerated procedure.

A common stump of the three hepatic veins has always been used to fashion the upper vena cava anastomosis in 205 liver transplantations with the piggyback (PGB) technique performed in our Unit, to avoid outflow problems. The aim was to study the repercussion of lateral inferior vena cava (IVC) clamping on IVC flow and pressure as well as on systemic hemodynamics. We have studied 42 orthotopic liver transplantations performed with the PGB technique. Intraoperative IVC blood flow measurements by transit time ultrasonic volume flowmetry, IVC pressure, and systemic hemodynamics were taken before and after lateral IVC clamping. Graft outflow complications, stenosis or kinking of the upper vena cava anastomosis have not been found in any of the 205 PGB procedures. A significant decrease of IVC flow (23%) and cardiac output (12%) occurred after IVC clamping, whereas mean arterial and central venous pressures were not altered significantly, probably due to an increase (25%) of systemic vascular resistance. Only in one case was an almost total clamping of IVC needed. Venovenous bypass was not needed in any case. Renal perfusion pressure was adequate in all cases. We conclude that the use of a common stump of the three hepatic veins for upper vena cava anastomosis in the PGB technique is safe because any outflow problem of the graft is avoided and, at the same time, is well tolerated hemodynamically because most of the IVC flow is preserved.

Constriction↗
PubMed1998

The expression of genes involved in parasitism by Trichoderma harzianum is triggered by a diffusible factor.

The mycoparasite Trichoderma harzianum has been extensively used in the biocontrol of a wide range of phytopathogenic fungi. Hydrolytic enzymes secreted by the parasite have been directly implicated in the lysis of the host. Dual cultures of Trichoderma and a host, with and without contact, were used as means to study the mycoparasitic response in Trichoderma. Northern analysis showed high-level expression of genes encoding a proteinase (prb1) and an endochitinase (ech42) in dual cultures even if contact with the host was prevented by using cellophane membranes. Neither gene was induced during the interaction of Trichoderma with lectin-coated nylon fibres, which are known to induce hyphal coiling and appressorium formation. Thus, the signal involved in triggering the production of these hydrolytic enzymes by T. harzianum during the parasitic response is independent of the recognition mediated by this lectin-carbohydrate interaction. The results showed that induction of prb1 and ech42 is contact-independent, and a diffusible molecule produced by the host is the signal that triggers expression of both genes in vivo. Furthermore, a molecule that is resistant to heat and protease treatment, obtained from Rhizoctonia solani cell walls induces expression of both genes. Thus, this molecule is involved in the regulation of the expression of hydrolytic enzymes during mycoparasitism by T. harzianum.

Base Sequence↗
PubMed1998

[Clinical and laboratory characteristics of patients with pathologic chronic gastroesophageal reflux].

BACKGROUND: Sixty percent of adults has typical symptoms of gastroesophageal reflux in Chile. AIM: To report the clinical and laboratory features of patients with gastroesophageal reflux. PATIENTS AND METHODS: Five hundred thirty-four patients (255 male) with gastroesophageal reflux were included in a prospective protocol that included clinical analysis, manometry and endoscopy in all patients, barium swallow in 427, scintigraphy in 195, acid reflux test in 359, 24 h pH in 175, and differential potential of gastroesophageal mucosa in 73 patients. RESULTS: There was no correlation between the severity of symptoms and the endoscopical severity. Patients with Barret esophagus were 12 years older, were male in a greater proportion and had a higher proportion of manometrically incompetent sphincters than patients with esophageal reflux but without esophagitis or with erosive esophagitis. Severity of acid reflux, measured with 24 h pH monitoring was proportional to the endoscopical damage of the mucosa. There was a close relationship between the mucosal change limit determined with differential potentials and with endoscopy. No short esophagi were found. CONCLUSIONS: Patients with symptoms of gastroesophageal reflux must be assessed using several objective measures to determine the severity of their pathological alterations.

Adult↗
PubMed1998

[Drug-induced agranulocytosis: clinical study of 19 cases].

Agranulocytosis is one of the most serious side effects to drugs. From January 1991 to June 1996 were diagnosed 19 cases of agranulocytosis associated with drugs at our hospital (incidence rate: 9.4 over million hab. per year). The average age was 62 and 11 cases were women. The drugs most commonly involved were metamizol and ticlopidine. In 15 of the patients fever blew up and 16 presented some infectious location. In 9 of the cases some positive microbiological culture was obtained, gram-negative bacilli being the commonest. G-CSF was used in 13 of the patients, observing a quicker haematological recovery (5.7 days vs 9.1, p = 0.07), though without any difference in mortality, which was of 0%. All this leads to the following conclusions: a high incidence of agranulocytosis in our environment and the important role of metamizol and ticlopidine in its origin.

Adult↗
PubMed1997

Recognition of an immunogenetically selected Trypanosoma cruzi antigen by seropositive chagasic human sera.

If the H-2 congenic mouse strains A.SW (H-2n) and A.CA (H-2f), are infected with Trypanosoma cruzi, a 45 kDa protein (Tc45), present in cultured epimastigotes and blood trypomastigotes, is recognized only by the A.SW strain sera. In order to explore the possibility that among seropositive humans the response to Tc45 is also highly variable, 81 chagasic human sera (as defined by the HemAve agglutination test, Polychaco S.A.I.C., Buenos Aires, Argentina) were tested in a direct (epimastigote antigenic complex directly bound to the solid phase) and indirect immunoradiometric assay (IRMA) (Tc45, from a partially purified preparation, bound to the solid phase, by means of a monoclonal antibody). Sixty nine of these sera reacted in both the direct and indirect assays, 11 were negative in both assays (these samples may correspond to false positives detected by the commercial agglutination test) and only one reacted with the antigenic complex but not with Tc45. Reactivity of the human sera with the epimastigote antigenic extract was relatively homogenous, while reactivity with Tc45 was extremely variable. No statistical correlation was determined between the two variables. Given the high variability of the human response to Tc45, ranging from negative to highly positive, together with the immunogenetic restriction previously described in the murine model, we speculate that human MHC may also modulate the response to this molecule.

Agglutination Tests↗
PubMed1997

Ocular tuberculosis. A prospective study in a general hospital.

Ocular tuberculosis has traditionally been considered uncommon or anecdotal. Imprecise and variable diagnostic criteria have contributed to the confusion surrounding this topic. The increase in extrapulmonary manifestations of tuberculosis during the AIDS era established the need for a prospective study of ocular involvement in patients with all types of tuberculosis using well-defined criteria. During a 15-month period, 300 cases had culture-proven tuberculosis at our institution. We randomly selected 100 for systematic ophthalmologic evaluation. Our criteria for ocular tuberculosis were divided as follows: certainty (isolation of Mycobacterium tuberculosis from ocular specimens), probability (patients with isolation of M. tuberculosis from extraocular samples, with ocular lesions not attributable to other causes that respond to anti-tuberculous treatment), and possibility (same as probability but follow-up impossible). Ocular tuberculosis was present in 18 patients (18%) of which 10 patients fulfilled probability and 8 patients fulfilled possibility criteria. Eleven of 18 patients had HIV infection. In 11 patients, ocular involvement was asymptomatic. Almost all patients (17/18) had choroiditis, and other ocular lesions included papillitis, retinitis, vitritis, vasculitis, dacryoadenitis, and scleritis. Multivariate analysis showed as risk factors independently predicting ocular involvement in patients with ocular tuberculosis the presence of miliary disease (odd ratio 43.92, p = 0.002), ocular symptoms (odds ratio 6.35, p = 0.0143), and decreased visual acuity (odds ratio 0.04, p = 0.012). We observed an unexpectedly high (18%) incidence of ocular involvement, frequently asymptomatic, in patients with tuberculosis. Miliary disease is a clear predisposing factor in both HIV-infected and noninfected populations. Ocular examination should be routinely considered in patients with proven or suspected tuberculosis.

AIDS-Related Opportunistic Infections↗
PubMed1997

Immunotherapy with standardized extract of Dermatophagoides pteronyssinus in bronchial asthma: a dose-titration study.

According to the maximum tolerated dose (MTD) achieved, we assessed the changes in clinical and laboratory parameters, induced by specific immunotherapy (SIT), in a group of 43 asthmatic patients sensitized to Dermatophagoides pteronyssinus, over a period of 18 months. A standardized extract (100 Bu/ml; 40 micrograms/ml of Der p 1; 20 micrograms/ml of Der p 2) was used. The patients were divided into two groups: the high-dose immunotherapy (HDI) group (MTD > or = 4 micrograms Der p I) and the conventional immunotherapy (CI) group (MTD < 4 micrograms Der p 1). Changes in clinical severity index, medication, and symptom scores; in cutaneous and conjunctival reactivity; and in the levels of specific IgE, IgG, IgG1, and IgG4 to D. pteronyssinus (Der p 1 and Der p 2) were measured (ELISA monoclonal antibodies). Safety was monitored according to the EAACI guidelines. The range of the MTD was 0.8-16 micrograms of Der p 1. Ninety percent of the patients tolerated a dose of 3.2 micrograms, but only 18% of the patients reached a maintenance dose of 16 micrograms. The medians of the accumulated dose were 197 micrograms of Der p 1 for the HDI group, and 50 micrograms for the CI group. Conjunctival and cutaneous reactivity was significantly lowered (P < 0.001) after SIT, as were the clinical severity score and medication score in both groups, without significant differences between the groups, except for cutaneous reactivity. Levels of specific IgE decreased significantly (P < 0.01) in both groups, again without significant differences between the groups. The range of the increase in medians of specific IgG, IgG1, and IgG4 was 4.4-120-fold for the HDI group and 3-24-fold for the CI group (P < 0.01). The increase in the levels of Der p 1 and Der p 2 IgG4 were correlated to the changes in cutaneous and conjunctival reactivity (P < 0.01). These results show that a maintenance dose of 3.2 micrograms Der p 1 (8 BU) can induce pronounced clinical and immunologic changes with an excellent safety profile.

Adolescent↗
PubMed1997

A computer program based on parallel line assay for analysis of skin tests.

A computer program for the analysis of differences or changes in skin sensitivity has been developed. It is based on parallel line assay, and its main features are its ability to conduct a validation process which ensures that the data from skin tests conform to the conditions imposed by the analysis which is carried out (regression, parallelism, etc.), the estimation of the difference or change in skin sensitivity, and the determination of the 95% and 99% confidence intervals of this estimation. This program is capable of managing data from independent groups, as well as paired data, and it may be applied to the comparison of allergen extracts, with the aim of determining their biologic activity, as well as to the analysis of changes in skin sensitivity appearing as a consequence of treatment such as immunotherapy.

Analysis of Variance↗
PubMed1996

[Subjective and objective evaluation of the results of laparoscopic antireflux surgery in patients with gastroesophageal reflux].

BACKGROUND: Laparoscopic antireflux surgery is a minimally invasive procedure that should have similar results than classical surgical treatment. AIM: To report the results of a prospective study of laparoscopic antireflux surgery in patients with gastroesophageal reflux. PATIENTS AND METHODS: Thirty two patients with gastroesophageal reflux and without Barret's esophagus, were subjected to endoscopy, manometry and measurement of intraesophageal pH before and after laparoscopic surgery. RESULTS: There were no postoperative deaths or complications. Gastroesophageal sphincter pressure and abdominal sphincter length increased from 9.1 +/- 3.9 to 13.0 +/- 3.5 mm Hg and from 8.1 +/- 6.2 to 13.5 +/- 5.4 cm after surgery (p < 0.01). There was a decrease in acid reflux in 82% of patients. CONCLUSIONS: Laparoscopic antireflux surgery reproduces exactly the results of open surgical procedures.

Adult↗
PubMed1996

Field evaluation of a diagnostic protocol for Chagas' disease and rangeliosis.

The present paper evaluates the protocol for the diagnosis of Chagas' diseases and rangeliosis that is suitable for use in remote and scarcely populated rural areas. Beginning with a blood sample taken by venipuncture in the rural dispensary from 350 inhabitants of Caserío La Sierra, Cojedes State, Venezuela, samples were analyzed at a laboratory located at a distance of 150 Km. Each blood sample was analyzed for blood and clot culture, artificial xenodiagnosis, inoculation into mice, complement fixation reaction (CFR), and indirect fluorescent antibodies test (IFA). Nine isolates of trypanosomes were obtained and identified as Trypanosoma rangeli, 29.4% of the blood samples showed seropositivity for Trypanosoma cruzi, 7.1% of total of persons between 6 and 18 years were found infected with T. rangeli, suggesting active transmission of this trypanosome in an endemic area for Chagas' disease. Results indicate that this protocol of study is reliable, economical and sufficiently versatile to study both rangeliosis and Chagas' disease.

Animals↗
PubMed1995

[Orthotopic liver transplant for giant cavernous hemangioma and Kasabach-Merritt syndrome].

We describe the case of a 42-year-old woman with giant cavernous hemangioma and Kasabach-Merritt syndrome. The patient presented with consumption coagulopathy due to intravascular, intratumoral coagulation as revealed by low platelet levels, fibrinogenopenia and an increase in fibrinolysis with high levels of fibrinogen degradation products. She was scheduled to receive an orthotopic liver transplant because of three factors: respiratory distress caused by compression of the diaphragm by the giant tumor; the risk of bleeding caused by spontaneous rupture or trauma; and the presence of Kasabach-Merritt syndrome due to consumption coagulopathy. Before surgery fibrinogen deficit was corrected with 4 units of cryoprecipitates and low platelet level was treated with 10 units of platelets. Coagulopathy during surgery was corrected with fresh plasma (17 units), cryoprecipitates (6 U), aprotinin (1 x 10(6) U/kg) and antithrombin 3 (2000 U). Blood loss was compensated for with 9 units of packed red blood cells. This report describes the procedures used for anesthesia, for prevention of accidental bleeding during surgery, hemodynamic control and preoperative coagulation testing.

Adult↗