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Biomedical subjects

D Perez

Publications and source records attributed to D Perez.

5 recordsLinked to original sources
PubMed1992

Synthesis of lactoferrin and transport of transferrin in the lactating mammary gland of sheep.

Two iron-binding proteins, lactoferrin and transferrin, are present in ruminant milk. Lactoferrin commonly has been assumed to be a product of mammary synthesis, but the origin of milk transferrin has not been elucidated. The objective of this experiment was to study the synthesis and distribution of these two proteins in the mammary gland of sheep. Explants from lactating mammary gland of sheep have been cultured in the presence of [3H]leucine to determine rates of synthesis of lactoferrin and transferrin. After incubation, [3H]lactoferrin was found, but labeled transferrin was not. The capacity of the mammary gland to synthesize lactoferrin decreased markedly in the first 24 h of lactation. Immunohistochemical techniques were utilized to identify the locations of lactoferrin and transferrin in the mammary gland. Transferrin was found in the colostrum contained in the alveolar lumen, in the cytoplasm of the secretory cells, and in the connective tissue between the mammary acini. High concentration of transferrin was found in the basal membrane of the secretory alveolar cells, mainly in those near capillary vessels. Lactoferrin was found in the colostrum and in the cytoplasm of secretory cells with a more homogeneous distribution than transferrin. The connective tissue stained negative for lactoferrin. These results suggest that, although lactoferrin is synthesized by mammary gland of the sheep, transferrin comes from blood serum, probably by a receptor-mediated mechanism of transcytosis.

Animals↗
PubMed1990

Carbon monoxide diffusing capacity is a poor predictor of clinically significant bleomycin lung. New Zealand Clinical Oncology Group.

In a retrospective analysis, serial lung function tests from 81 patients receiving bleomycin were studied to determine the accuracy of carbon monoxide diffusing capacity (DLCO) as a predictor of clinically significant bleomycin lung. Six of 81 patients developed clinically significant bleomycin lung, and the DLCO predicted its development in only one patient (sensitivity, one of six patients; 16.7%). Respiratory symptoms and chest x-ray abnormalities were the earliest manifestations in the other five patients. Seventy-five of 81 patients did not develop clinically significant bleomycin lung, and 12 of these had major falls (greater than or equal to 35% pretreatment level) in DLCO (specificity, 63 of 75 patients; 84.0%). In eight patients, bleomycin was continued after a major fall in DLCO, and none developed clinically significant lung toxicity. In this study, the DLCO failed to predict the development of serious bleomycin lung toxicity in all but one case. Furthermore, in some patients, it would appear that bleomycin may be stopped inappropriately after low DLCO measurements. It is important to monitor for respiratory symptoms and chest x-ray abnormalities during bleomycin treatment as these will be the earliest signs of lung toxicity in most cases.

Adolescent↗
PubMed1978

Effects of sulfuric acid aerosol on cardiopulmonary function of dogs, sheep, and humans.

Submicronic aerosol of sulfuric acid (H2SO4) originates from the burning of fossil fuels and discharge of vapor from the automobile engine equipped with the catalytic converter. This study was conducted to determine whether brief exposure to this aerosol in high concentrations adversely affects the cardiopulmonary system. In all studies, submicronic aerosol of sodium chloride was used as a control. Anesthetized dogs that breathed H2SO4 aerosol in concentrations up to 8 mg per m3 showed no effects on respiratory resistance, static lung compliance, and functional residual capacity. A 4-hour exposure to H2SO4 aerosol (4 mg per m3) produced no significant changes in mechanics of breathing, functional residual capacity, pulmonary and systemic arterial blood pressures, cardiac output, heart rate, and arterial blood gas tensions. Conscious sheep that breathed H2SO4 aerosol in concentrations up to 14 mg per m3 for 20 min had no alteration of tracheal mucous velocity in an immediate 3-hour follow-up period or 5 to 10 days later. Conscious sheep that breathed H2SO4 aerosol (4 mg per m3) for 4 hours had no significant alteration of tracheal mucous velocity immediately and 2 hours thereafter. Both normal and asthmatic adults breathing H2SO4 aerosol in concentrations up to 1 mg per m3 for 10 min showed no significant alteration of lung volumes, distribution of ventilation, ear oximetry, dynamic mechanics of breathing, oscillation mechanics of the chest-lung system, pulmonary capillary blood flow, diffusing capacity, O2 consumption, and pulmonary tissue volume. No delayed effects in pulmonary function nor exacerbation of bronchial asthma were observe during a follow-up period of a few weeks. The present study indicates that single exposure to submicronic H2SO4 aerosol does not produce an immediate or a delayed adverse effect on cardiopulmonary function in anesthetized dogs, conscious sheep, and normal and asthmatic adults.

Aerosols↗
PubMed1978

Hyperimmunoglobulin E syndrome.

A 24-year old woman had the major features of the hyperimmunoglobulin E syndrome: recurrent staphylococcal skin infections (from the age of 6 months), an extremely elevated serum immunoglobulin E level (25,000 units/ml), and defective neutrophil chemotaxis. This patient also had peripheral blood eosinophilia and cutaneous candidiasis. There was a family history of asthma, but the patient herself did not have a history of asthma or hay fever, and, on examination, had no evidence of atopic dermatitis. The patient has not had any systemic infections. Results of the skin biopsy showed dermal edema and a perivascular infiltrate with eosinophils and an increased number of mast cells. The clinical spectrum of the hyperimmunoglobulin E syndrome may include atopic dermatitis, mucocutaneous candidiasis, systemic infections, and/or the features of Job's syndrome.

Adolescent↗