Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Breast secretions can be classified into two types according to their major protein components. Type I fluids contain Zn-alpha 2-glycoprotein, apolipoprotein D, and gross cystic disease fluid protein-15, while Type II fluids are characterized by the presence of lactoferrin, lysozyme, and alpha-lactalbumin. In this study, the polypeptide composition of breast secretions from 719 nonlactating women was evaluated by using polyacrylamide gel electrophoresis. The required amount for the analysis (1 microliter) was obtained from 50% of control women and from 75% of women with mammary disease. There were more secretors in premenopausal than in postmenopausal women, as well as in parous than in nulliparous women. Evaluation of factors affecting protein composition of breast secretions revealed that Type II fluids were found in the majority of women who had given birth in the last four years and in a high proportion of oral contraceptive users. After excluding both of these groups, Type II fluids were detected in 47% of patients with breast cancer, but only in 8% of control women and in 16% of women with benign breast diseases. Taken together, these results suggest that protein analysis of breast secretions could be an useful tool for the study of breast pathologies.
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PMID:Factors affecting protein composition of breast secretions from nonlactating women. 146 65

The protein composition of breast secretions from 99 premenopausal women with benign or malignant breast diseases and from 70 control women without breast pathologies has been studied by using polyacrylamide gel electrophoresis. These fluids have been classified into two types according to their major polypeptide components. Type I fluids are defined by three major distinctive bands at Mr 44,000, 24,000, and 17,000, while those designated Type II present distinctive bands at Mr 80,000, 15,000, and 14,000. Amino acid sequencing and immunoblotting analysis demonstrated that proteins in Type I secretions correspond to Zn-alpha 2-glycoprotein, apolipoprotein D, and gross cystic disease fluid protein-15, while those from Type II fluids have been identified as lactoferrin, lysozyme, and alpha-lactalbumin. Most women (93%) without breast pathology and most patients (88%) with benign diseases had secretions with a Type I polypeptide pattern. By contrast, a large percentage (57%) of secretions from women with breast carcinoma presented a Type II protein pattern. Further studies with a large number of women will be useful for corroborating the potential clinical interest of breast fluid protein analysis.
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PMID:Identification of the major protein components in breast secretions from women with benign and malignant breast diseases. 172 90

The potential relationship between serum PRL levels and protein composition of breast secretions was evaluated in 54 premenopausal nonlactating women during the luteal phase of their menstrual cycle. Women were classified into four groups according to the presence or absence of breast pathology and to the protein pattern of their breast secretions. Type I mammary fluids contain Zn-alpha 2-glycoprotein, apolipoprotein D, and gross cystic disease fluid protein-15, whereas Type II fluids are characterized by the presence of some milk proteins such as lactoferrin, lysozyme, and alpha-lactalbumin. Basal serum levels of PRL, as well as of progesterone, LH, FSH, TSH, T3, and T4 were within normal range, and no significant differences were found between the different groups of women under study. However, after a TRH stimulation test, the maximum PRL response was significantly higher (P < 0.02) in normal women with Type II secretions than in those with Type I (64 +/- 6.8 micrograms/L vs. 43.7 +/- 3.9 micrograms/L). Similarly, when PRL concentrations in patients with benign breast disease were considered, those with breast fluids containing milk proteins had a rise in PRL secretion after TRH stimulation significantly higher (P < 0.05) than those with fluids lacking these proteins (77.1 +/- 6.2 vs. 58.8 +/- 5.1 micrograms/L). These results indicate that the occurrence of milk proteins in breast secretions from nonlactating women is associated with an increase in serum PRL concentrations after TRH stimulation, and opens the possibility of using breast fluid protein analysis as a simple and noninvasive procedure for studies on the putative role of PRL in the development of benign and malignant breast diseases.
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PMID:Relationship between serum prolactin levels and protein composition of breast secretions in nonlactating women. 804 72