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Biomedical subjects

L F Fajardo

Publications and source records attributed to L F Fajardo.

At least 73 records · Page 4Linked to original sources
PubMed1980

Posterior ocular abnormalities after irradiation for retinoblastoma: a histopathological study.

Radiation-induced ocular lesions in the posterior eye and orbit were investigated in 33 surgical specimens of patients with retinoblastoma. The eyes were obtained from children 7 months to 6 years of age. Seventeen eyes were irradiated; 16 eyes had not received irradiation and served as controls. The majority of the irradiated eyes were treated with 6000 rads of external beam radiation. They were removed at a mean of 23 months after radiotherapy. All specimens were examined simultaneously by 2 observers without knowledge of treatment and analysed for the presence or absence of 15 lesions. The most consistent lesions in the irradiated eyes were abnormalities of the retinal vessels (11 of 17 eyes) and striking changes in the ciliary arteries (13 of 17 eyes). The retinal vessels showed thickening of the wall, often caused by deposition of fibrillary material, sometimes with fibrin deposits. The most consistent lesion was myointimal proliferation with narrowing of the ciliary arteries. Lesions of the central retinal artery were less common but occurred only in irradiated patients.

Child↗
PubMed1980

Pathogenesis of veno-occlusive liver disease after radiation.

Radiation-induced liver disease is characterized structurally by progressive fibrous obliteration of central veins (veno-occlusive disease [VOD]). The pathogenesis is unknown. Samples of liver from 11 patients with radiation-induced VOD were studied by light and electron microscopy for evidence of central vein thrombosis. The patients had received fractionated radiation with total doses of 1,850 to 4,050 rads, or single doses of 1,000 rads. In addition, six patients had received chemotherapy. Although usually undetectable by light microscopy, fibrin was found in all samples, sometimes in large amounts, within central veins, and also often in the adjacent sinusoids. One sample had a small platelet aggregate. In two patients, portal veins also showed occlusive lesions. We postulate that ionizing radiation injures preferentially the endothelial cells of central veins, which leads to focal deposition of fibrin. The resulting fibrin network is eventually replaced by collagen, causing fibrous occlusion. In several patients, this type of liver injury occurred at radiation doses conventionally considered safe even in the absence of chemotherapy.

Adolescent↗
PubMed1979

[Milk intolerance in Colombian children, its prevalence and relation to lactose malabsorption].

A total of 121 children from an orphange were studied. Their ages ranged from 2 to 10 years and represented different ethnic backgrounds. The prevalence of malnutrition was 45% and their gastrointestinal symptomatology in response to graded amounts of milk intake was evaluated. None of the children complained when milk intakes were of 200 cc; 10% complained of gastrointestinal discomfort and/or diarrhea when 300 cc of milk (equivalent to 12 g of lactose) were administered, and 54% presented lactose malabsorption unrelated to ethnic background, sex or malnutrition. It is concluded that the prevalence of milk intolerance is minimal when milk is given in the usual amounts.

Age Factors↗
PubMed1979

The role of platelets in infections. I. Observations in human and murine malaria.

The interaction between platelets and microorganisms may be underestimated. Our in vivo studies support a direct role of thrombocytes in malarial infections. We have found intrathrombocytic parasites of Plasmodium vivax (in 10% of men naturally infected) and P berghei (in 53% of mice experimentally infected); these were both merozoites and trophozoites. Neither the mechanism of parasitization (whether by active penetration or by phagocytosis) nor the outcome of this phenomenon is known. However, structures suggestive of partially digested parasitic material were seen in platelets of almost 50% of the men and 75% of the mice. These findings suggest that other microoganisms (fungi, bacteria, and viruses) may also enter thrombocytes in vivo. If so, platelets could play important roles, either favorable or deleterious, in infections.

Adult↗
PubMed1977

Screening for malnutrition with arm circumference.

The opinions on the performance characteristics of the mid arm circumference as anthropometric measurement for malnutrition screening are quite contradictory. In this paper we analyze the specificity and sensitivity of the arm tape under different conditions and conclude that the design of the tape characteristics should aim at an instrument which can satisfy specific needs instead of a general purpose one. We also give some measurements for the practical design of the instrument. 1. This investigation has been carried out under the Contract AID/ta-C-1121 and the Fundación para la Educación Superior. 2. Universidad del Valle. 3. Fundación para la Educación Superior. 4. Community Systems Foundation.

Anthropometry↗
PubMed1977

Comparative analysis of some anthropometric measurements.

The main objective of this work is to determine what anthropometric method to use under field conditions, given the kind of mainutrition to be detected. In the first part of the work some criteria and procedures are given by which to compare the field perfomance characteristics (i.e. transportability, facility of use, etc.), of the most commonly used instruments. Then we extrapolate these characteristics to the respective methods like weight for age, weight for height, height for age, etc. In the second part we present a correlation matrix among the various methods and analyze it in order to associate with each method a specific typology of malnutrition.

Age Factors↗
PubMed1977

Oxalosis and chronic renal failure after intestinal bypass.

A 45-year-old man underwent a jejunoileal shunt procedure for obesity. Twenty months later he developed severe oxalosis and chronic renal failure, which required maintenance hemodialysis. The sequential observation of two biopsy specimens and the necropsy (over a span of 39 months) suggests that oxalate deposition caused tubular obstruction and destruction with subsequent atrophy of nephrons. This indicates that patients undergoing intestinal bypass are at risk for developing irreversible renal failure due to enteric hyperoxaluria.

Humans↗
PubMed1976

Combined cardiotoxicity of adriamycin and x-radiation.

Our previous studies have shown that x-radiation produces cardiac lesions. Likewise, adriamycin, a useful antineoplastic agent, is known to be cardiotoxic. Maximal "safe" doses have been established for each of these forms of therapy. Since combined therapy with adriamycin and radiation is being used for malignancies involving the mediastinum, it is important to know whether the combination of both agents is more cardiotoxic than either agent alone. In this study young New Zealand White rabbits were divided into five groups and given: (1) a single dose of x-radiation of 1600 rads in the cardiac area; (2) 167 mg. per sq. m. of adriamycin; (3) both raddiation and adriamycin at the same doses; (4) 255 mg. per sq. m. of adriamycin; (5) no treatment. Animals in the third (combined) group developed radiation and adriamycin lesions, the frequency and severity of which were greater than those in the single therapy groups at the same (low) doses. These observations suggest a synergistic effect of the two agents. If so, patients receiving combined treatment are at risk of developing severe carditis from doses of adriamycin and cardiac x-radiation today regarded as safe. Although neither one is specific, the light and electron microscopic lesions caused by x-radiation (myocardial capillary damage, pericarditis) were easily distinguished from those caused by adriamycin (myocyte damage). Both agents led to diffuse myocardial fibrosis. These morphologic characteristics may have clinical applications.

Animals↗
PubMed1975

Rupture of major vessels after radiation.

Rupture of irradiated large vessels is an uncommon complication which tends to occur in carotid, aorta, and femoral arteries, in decreasing order of incidence. It particularly affects men subjected to surgery and radiotherapy for epidermoid carcinomas in oropharynx, esophagus, or genitalia. Contrary to some opinion, radiation is not the most significant cause; this "spontaneous" arterial rupture can occur without radiation. The perforation is not associated with tumor invasion of arterial wall, as has been claimed. Surgical complications, especially necrosis of skin flaps, infection, and fistulas are most important etiologically. Only 2 of the 11 instances that we describe appear to have been caused mainly by radiation. The perforation is usually fatal, but several patients, including 3 of our series (2 carotid, 1 femoral), have been saved by hospital personnel aware of this complication. To prevent it, prolonged exposure or infection of arteries, whether irradiated or not, should be avoided.

Aged↗
PubMed1975

Platelet morphology after aspirin.

Previous studies have revealed morphologic platelet abnormalities, particularly inclusions, in patients who have acute malarial infections. To determine the possible role of aspirin (ASA) in the etiology of these abnormalities, the thrombocytes of 14 normal men were examined before and after ingestion of 2 Gm. of ASA. A significant decrease in platelet size was noticed after ASA: however, no ultrastructural alteration of these circulating platelets was found, although functional impairment was manifested in vivo (bleeding time) and in vitro (aggregation). It is concluded that inclusions and other morphologic abnormalities in thrombocytes of malaria patients are not caused by aspirin ingestion.

Adult↗
PubMed1975

An evaluation of cryosurgery for basal cell carcinoma.

Fifteen histologically proven basal cell carcinomas were treated by conventional cryosurgery. Three to 6 months following healing, the entire treated area was excised and serially sectioned. There was clinical and microscopic evidence of residual tumor in two of the 15 cases and microscopic evidence of recurrence in one additional patient (20 percent recurrence).

Adult↗