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Biomedical subjects

C Cortés

Publications and source records attributed to C Cortés.

At least 37 records · Page 2Linked to original sources
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

Molluscum contagiosum, involving the upper eyelids, in a child infected with HIV-1.

BACKGROUND: Infection with molluscum contagiosum has been reported in pediatric and adult patients with acquired immune deficiency syndrome (AIDS), but rarely affecting eyelids. We have studied the viral phenotype, HIV-1 plasma viremia, p24 antigenemia, alterations of cellular immune function, and the ophthalmological status in a 5-year old human immunodeficiency virus type 1 (HIV-1)-infected girl, who developed multiple molluscum lesions, bilaterally involving upper eyelids with extension over the face and nose. METHODS: Detailed ophthalmological examination and immunological and virological studies were performed in a pediatric patient with HIV-1 vertical infection having extensive infection with molluscum contagiosum. RESULTS: The pediatric patient was emetropic; tricomegalia was present bilaterally, and alteration of the microvessels of the conjunctiva (microangiopathy) was observable in both eyes and structural (fibrilar) degeneration of the vitreous architecture in both eyes. There was no ophthalmoscopic sign of infectious retinitis or retinal microangiopathy. She had lymphopenia, very low percentage and absolute number of CD4+ T cells but increased percentage of CD8+ T cells. The in vitro lymphocyte proliferative response to phytohemagluttinin (PHA) was depressed as compared to healthy controls. She had high levels of viral HIV RNA in her plasma and of p24 antigen in her serum, and the phenotype of the isolated HIV-1 was determined to be syncytium-inducing (SI). CONCLUSION: Although healthy persons may develop molluscum contagiosum, usually unilateral, as far as we are aware this report is the first to document a case of molluscum contagiosum with bilateral eyelid involvement in an HIV-1-infected pediatric patient. Our observations suggest that this type of infection may be present in HIV-infected children, associated with high viral load and possibly an SI viral phenotype, severe immunoregulatory abnormalities, and poor clinical status.

AIDS-Related Opportunistic Infections↗
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↗
PubMed1994

[Migratory regional osteoporosis. Effect of treatment with calcitonin. Report of 2 cases].

We report two cases of regional migratory osteoporosis. One is a 41 years old male, with the classical form, presenting with successive episodes of painful osteoporosis lasting for 5 months at the hip, knee and distal epiphysis of the right metatarsophalangeal joints. The second case is a 40 years old female presenting with an unusual disseminated form, lasting for 30 months, with successive and simultaneous episodes of polyarticular and costal painful osteoporosis. An increased bone fraction of serum alkaline phosphatases and urine hydroxyproline/creatinine and calcium/creatinine ratios were detected. Imaging showed localized periarticular or costal osteoporosis. Bone biopsies disclosed a severe osteopenia with accelerated bone reabsorption. Bone scintigraphy precociously detected location, migration and evolution of lesions. Patients were treated with subcutaneous calcitonin, 100 U/day during 1 month and on alternative days posteriorly; this treatment alleviated pain but did not prevent the appearance of new crisis. Our observations suggest that regional migratory osteoporosis presentation may range from oligoarticular to disseminated forms and that calcitonin has a precocious and persistent analgesic effect.

Adult↗
PubMed1992

[Characteristics of severe esophagitis in patients with collagen diseases].

Connective tissue disease may alter esophageal function generating symptoms due to gastroesophageal reflux and motor disturbances. Fifteen patients with connective tissue diseases and severe esophagitis defined by the presence of esophageal stenosis or ulcerations were studied. Diagnosis was made with radiologic, endoscopic and manometric studies. Dysphagia was present in 11 and gastroesophageal reflux in all. All patients has an hypotensive and shorter lower esophageal sphincter. Better therapeutic results were obtained with surgical treatment.

Adult↗
PubMed1992

[Mortality from childhood and adolescent leukemia in Spain (1951-1985)].

PURPOSE: To study the mortality due to leukaemia during childhood and youth in Spain in the period 1951-1985. MATERIAL AND METHODS: The mortality for all types of leukaemia in that period was studied in three aspects: (a) By reviewing the rates of specific mortality for ages under 20 years, at quinquennial intervals and per millions of inhabitants of those ages. (b) Studying the mortality per cohorts of births at five-year intervals from 1951-1955 to 1981-1985. (c) Attaining the statistical value, "observed deceased" of leukaemia in people under 15 years of age for the period studied and on each year of that period, and comparing such value with the number of "expected deceased", with regard to the reference year, 1965. RESULTS: A decreasing trend was observed along the whole period. As for ages, there seems to be some tendency to stabilisation of the mortality in the last five-year period, 1981-1985 (there is a decrease only in the 15-18 age-group). These data were confirmed when assessing the mortality per "birth cohorts" or generations, and after plotting the figures of "observed" and "expected" mortality in accordance with the previous evolution. CONCLUSION: It was inferred that regard to the mortality of childhood and youth leukaemia, in Spain the situation has improved markedly, doubtless as a result of better therapeutical approach. This evolution closely resembles the patterns of the most developed countries from a sanitary standpoint.

Adolescent↗
PubMed1990

Lay understanding of low-frequency electric and magnetic fields.

People do not start with a blank slate when they hear risk-communication messages. All such messages are processed through existing knowledge structures and understanding. Hence, to design effective and reliable risk-communication materials one must understand the state of people's knowledge--correct and incorrect--about an issue. We developed a simple "mental model" of what people minimally need to know to make informed decisions about field-related issues. Then we performed studies to explore how and to what extent respondents of various groups understood physical properties of 60-Hz electric and magnetic fields. Actual knowledge of respondents was then compared with the predicates of the model. Electrical engineering juniors and semi-technical employees of utilities displayed a good command of most of the concepts in the simple model, but little awareness of the limits to their knowledge. Lay respondents correctly knew only a few of the simplest elements of the model, but they displayed a much greater awareness of the limits to their knowledge. Both lay and semi-technical respondents were found to share several misconceptions. On average, they correctly rank-ordered some common field-exposure conditions by field strength, but they could not differentiate between electric and magnetic fields and could not differentiate among field strengths associated with different appliances. Most respondents dramatically underestimated the range of actual field strengths. Many respondents understood that field strength decreases with distance from a source, but they underestimated the rate of decrease. In contrast to X-rays and microwaves, which respondents appeared to think about in rather similar terms, 60-Hz fields were not thought of as being highly similar to any other agent, although the closest parallels were found with ultrasound. Changes in mood, thought, and behavior, and the existence of an "electrical aura," were all seen as plausible results of exposure to a 60-Hz field. Although lay respondents displayed a variety of incomplete and confusing ideas, most of these ideas probably do not pose significant obstacles to the learning of a correct, simple, mental model.

Communication Barriers↗
PubMed1989

Late results of a prospective randomised study comparing forceful dilatation and oesophagomyotomy in patients with achalasia.

Late results in 81 patients with achalasia treated in a prospective randomised study comparing forceful pneumatic dilatation with the Mosher bag and surgical anterior oesophagomyotomy by abdominal route, are reported. There were no deaths from either of the treatments. Two patients (5.6%) had a perforation of the abdominal oesophagus after pneumatic dilatation and were excluded from late follow up. In patients having surgery at radiological evaluation there was gullet diameter significantly increased at the oesophagogastric junction and decreased at the middle third of the oesophagus. One patient was lost from follow up and one died of an oesophageal carcinoma, leaving 95% of excellent results at the late follow up (median 62 months). Resting gastro-oesophageal sphincter pressure decreased significantly to approximately 10 mmHg; this was maintained five years after surgery. By contrast, in patients having pneumatic dilatation, there were good results in only 65% (follow up median 58 months), with 30% failures. One patient was lost from follow up and one developed oesophageal carcinoma. Measurement of resting gastro-oesophageal sphincter pressure after dilatation was highly predictive of the outcome. The study shows that surgical treatment offers a better final clinical result than pneumatic dilatation with the Mosher bag.

Adolescent↗
PubMed1989

[Cancer of the testis: risk factors and evolution of mortality in Spain (1951-1983)].

Herein we report the results of a study on the mortality trends of testicular cancer in Spain from 1951-1983. The study showed that following a long period of increased mortality, overall mortality rates for all age groups have dropped in recent years. However, the mortality rate has increased for the young and middle-aged males and has dropped for the older age groups. A similar finding has been observed for other countries such as the United States. We have attempted to interpret these changes based on the risk factors for this type of cancer.

Age Factors↗
PubMed1989

Late subjective and objective evaluations of antireflux surgery in patients with reflux esophagitis: analysis of 215 patients.

The results of late subjective and objective evaluations of antireflux surgery in 215 patients with reflux esophagitis who were included in a prospective, controlled study are reported. A special protocol--including analysis of reflux symptoms, radiology, endoscopy, esophageal manometry, and standard acid reflux test--was designed. The surgical technique used was as follows: (1) highly selective vagotomy, (2) closure of the hiatus, (3) calibration of the cardia, (4) posterior gastropexy, and (5) fixation of the gastric fundus to the diaphragm. The operative mortality rate was 0.4%, and postoperative complications occurred in 5% of the patients. Only 5% of the patients were lost from the late follow-up. A total of 150 patients with more than 5 years since operation were completely evaluated. Reflux symptoms greatly decreased after surgery. Radiologic studies were normal in 93% of the patients, and endoscopy showed a long-standing healing of macroscopic esophagitis in 83% of the cases. Manometric features were analyzed in 159 patients before and in 115 patients 1 year after surgery. A significant increase in lower esophageal sphincter pressure was demonstrated, as well as an increase in the total length and abdominal length of this sphincter (p less than 0.0001). The increase in gastroesophageal sphincter was evaluated in 46 patients 1 year and 5 years after surgery, and this showed a maintenance of sphincter competence. Esophageal clearance markedly improved after surgery, and the standard acid reflux test, which was positive in 100% of cases before surgery, persisted positive in 16% (p less than 0.001). Final clinical evaluation 5 years after surgery demonstrated excellent and good results in 85% of the patients and failure or reoperation in 8% of the patients.

Adolescent↗
PubMed1987

Cross-reactivity among five major pollen allergens.

We have studied the cross-reactivity between L. perenne, S. cereale, P. pratense, C. dactylon, and Ph. communis. The results obtained demonstrate that L. perenne, S. cereale, and P. pratense have strong cross-reactivity. C. dactylon has a number of allergens that cross-react with the rest of the grasses studied but they are minor allergens. Ph. communis possesses a moderate cross-reactivity with the species of the group but it has, as well, individual allergens.

Allergens↗