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Biomedical subjects

F Villarroel

Publications and source records attributed to F Villarroel.

At least 19 recordsLinked to original sources
PubMed1999

[Treatment of non infectious ocular inflammatory disease with low doses of cyclosporin A].

BACKGROUND: Cyclosporin A has an adequate immunosuppressive capacity and can be useful in the treatment of non infectious ocular inflammatory diseases. AIM: To describe the clinical effect of cyclosporin A treatment in low doses, along with corticosteroids, in the treatment of refractory ocular inflammatory diseases. PATIENTS AND METHODS: Twenty patients (13 female), aged 17 to 74 years old with severe and refractory ocular inflammatory diseases were studied. All except one, received variable doses of prednisone (10 to 60 mg/kg/day) and all received cyclosporin in doses that started in 2.5 mg/day and were increased to 5 mg/kg/day, according to clinical response. Patients were followed from 8 to 24 months, with monthly assessments of ocular inflammation (using a four point score), visual acuity and adverse effects of treatment. RESULTS: A two points or more reduction in the ocular inflammation score was observed in 52% of patients. Visual acuity improved in 10 subjects, stabilized in 8 and worsened in 2. Prednisone doses were reduced in most patients. Observed adverse effects were hypertension in 2 patients, creatinine elevation in 2, gastrointestinal disturbances in 3 and hypertrichosis in 12. A reduction of cyclosporin dose was required in these cases, but it was discontinued only in one patient with a vascular purpura. CONCLUSIONS: Low cyclosporin doses, associated to prednisone, are useful to reduce inflammation and improve visual acuity in patients with non infectious ocular inflammatory diseases, refractory to other treatment methods.

Adolescent↗
PubMed1987

First-use syndrome in patients treated with hollow-fiber dialyzers.

A 2-year survey on first-use syndrome (FUS) in hemodialysis showed that there were an average of 181 FUS reactions per year. Nearly 39% of the patients who experienced a FUS reaction had experienced previous FUS reactions. No correlation was found between the frequency of FUS reactions and the sex of the patient, however, a strong correlation was found with respect to the age and race of the patients. The fact that a patient recently started dialysis treatment or has been treated with dialysis for some time appears to have no bearing in the risk of experiencing a FUS reaction.

Adolescent↗
PubMed1985

A survey on hypersensitivity reactions in hemodialysis.

This survey was conducted from 1982 through 1984 by a cooperative effort among the Health Industries Manufacturers Association, seven dialyzer manufacturers, and the Food and Drug Administration. This article presents an analysis of the 1982-83 survey data and a summary of the 1984 data. Most of the reactions reported (99%) were associated with hollow-fiber dialyzers. About 50% of these reactions were experienced by patients using a dialyzer model for the first time, and greater than 98% of the reactions were related to new (unused) dialyzers. On average, there were 180 reactions reported per year, with greater than 90% being considered severe, including death, by the reporting center. A plot of the number of reactions versus time from 1982 through 1984 shows periods of 12-15 months in which the reaction rate remained practically constant. During these periods, the rate of reported reactions alternated from 60 to 150% of the average. Analysis of the survey data showed a strong correlation of the number of reactions with the race and age of the patients. Blacks and other minorities experience nearly three times as many reactions as white patients. Also, patients under 29 years of age seem to have nearly twice as many reactions as patients in the 30- to 49-year-old range, whereas patients over 50 years old have nearly half the number of reactions of the 30- to 49-year-old range. The average reactivity of the U.S. hemodialysis patient population was calculated to be 3.3 reactions per year per 1,000 patients exposed to hollow-fiber dialyzers and 0.3 reaction per year per 1,000 patients exposed to flat-plate dialyzers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Incidence of hypersensitivity in hemodialysis.

Hypersensitivity reactions in hemodialysis are rare. They have been identified only recently, since the U.S. dialysis patient population became sufficiently large for pattern recognition. These reactions might be the result of a variety of factors, including the manufacturing process and patient characteristics. Some reactions may be due to components of the dialysis system other than the dialyzer, such as the tubing sets. Data collected by the Food and Drug Administration showed that in 1982 there were 3.5 severe hypersensitivity reactions per 100,000 hollow-fiber dialyzers sold. This rate of reaction occurrence does not appear to be appreciably different from that in previous years for which information, though scant, was available. Recently, a significant reduction in the rate of the reactions seems to have occurred after some U.S. manufacturers changed their manufacturing procedures.

Cross-Sectional Studies↗
PubMed1978

Evaluation of permeance in peritoneal dialysis.

Evaluation of permeance in peritoneal dialysis. Relations were developed to calculate permeance based on a minimum number of experimental measurements. Permeance is the product of the effective peritoneal area times its mass transfer coefficient. The relations were used on clinical data obtained with and without nitroprusside, a direct vasodilator, added to the dialysate. Nitroprusside increased permeance 34% for BUN and about 100% for creatinine and inulin. The equivalent increase in clearance in a 50 minute exchange protocol would be 24, 60, and 83%. Normalized consecutive concentration data obtained every ten minutes in several long exchanges agree well with calculated values supporting the adequacy of the approach. An expression is also given to calculate the residual dialysate volume left from the previous dialysate exchange. The values calculated ranged from 200 to 500 ml.

Mathematics↗
PubMed1977

Kinetics of intermittent and continuous peritoneal dialysis.

Relations were developed for clearance under both intermittent and continuous flow peritoneal dialysis. The theoretical prediction was compared with data from other investigators. A mass transfer characteristic of 52 ml/min per 1.85 liters of dialysate was determined for urea from Boen's single batch experiment. This number was used to calculate the value of clearance for intermittent dialysis versus rate of dialysate exchange. The calculated clearances are in good agreement with Boen's experimental results. The calculated urea clearances for continuous flow dialysis were compared with Shinaberger's data. The predicted curve is in reasonable agreement with the data although there is a rather large scatter of the points. Some possible explanations for the scatter are provided as a caviat for future experimental research. A theoretical comparison between intermittent and continuous flow clearances shows that the latter is more efficient, particularly at higher flow rates.

Ascitic Fluid↗
PubMedDate not supplied

[Loxoscelism in Chile. Epidemiologic, clinical and experimental studies].

A panoramic sight of epidemiological, clinical and experimental studies, referring to Loxosceles laeta and loxoscelism, carried out in 1955-1988, in Santiago, Chile is presented. Two-hundred and sixteen cases of loxoscelism were studied. The most relevant features were: 84.3% corresponded to cutaneous loxoscelism (CL) and 15.7% to viscerocutaneous loxoscelism (VCL); 73.6% occurred in hot season; in 86.6% of cases the accident happened in the house, particularly in bedrooms, while the people were sleeping or dressing. The spider was seen in 60.2% of cases and identified in the laboratory as L. laeta in 10.6% of all cases. The sites more frequently bitten were the limbs with 67.6%; a burning-stinging was the most frequent initial symptom. Pain, edema and livedoid plaque, which developed later into a necrotic eschar, were the predominant local manifestations. In VCL, hematuria and hemoglobinuria were constant, while jaundice, fever and sensorial involvement were present in most of the cases. CL patients were parenterally treated with antihistaminic drugs or corticoids, while VCL ones were treated with corticoids by injection. The condition of patients in the last follow up was: complete cure in 75.5%, cure with a scarfed sequela in 8.3%, death in 3.7% (all VCL) and abandonment in 12.5%. Additionally, a series of experimental studies, both in vivo and in vitro, has been performed in order to clarify basic aspects on L. laeta venom and the treatment of loxoscelism.

Adolescent↗
PubMedDate not supplied

Seroepidemiology of human toxoplasmosis in Chile.

A series of already published and unpublished seroepidemiological surveys for toxoplasmosis, carried out in Chile in 1982-1994, is reviewed, expanded and analyzed. The surveys included 76,317 apparently healthy individuals of different ages (0.57% of the country's total population), from 309 urban and rural-periurban localities. Urban groups were integrated by blood donors, delivering mothers and middle grade schoolchildren, while rural-periurban individuals corresponded to unselected family groups. Blood samples were collected in filter paper. The presence of antibodies to Toxoplasma gondii was determined by the indirect hemagglutination test (IHAT), titers > or = 16 were considered positive. The test resulted positive in 28,124 (36.9%) of the surveyed people. Two hundred and six (0.3%) individuals presented IHAT titers > or = 1000, probably corresponding to acute or reactivated infections. A progressive increase of positive IHAT from northern to southern regions of the country was noted, phenomenon probably related to geographical conditions and to a higher production and consumption of different types of meat in the latter regions. It is postulated that ingestion of T gondii cysts by humans is epidemiologically as important as ingestion of oocysts. The result presented stress the epidemiological importance of toxoplasmosis in humans, and warn about eventual implications in immunocompromised patients and in transplacental transmission, organ transplants and transfusions.

Adult↗