Microanatomy of milk ducts in the nipple.
ABSTRACT The aim of this study was to determine number and diameter of milk ducts in the nipple and to investigate the possible influences of age, breast weight, and diameter of the nipple on the number of ducts. Two hundred and twenty-six carcinoma mastectomy specimens were weighed and the nipple diameters measured. The number of ducts was counted in histological cross sections. Mean diameter of the nipple and mean breast weight were 13.9 mm and 844.6 g, respectively. There was a small but statistically significant positive correlation between nipple diameter and number of milk ducts (rho = 0.158; p = 0.01), but no correlation with breast weight. The mean number of ducts in the nipple duct bundle was 17.5. This is significantly higher than the number of ducts reported to open on the nipple surface. This discrepancy could reflect duct branching within the nipple or the presence of some ducts which do not reach the nipple surface. Smaller breast ducts (diameter < 0.5 mm) represent nearly 50% of the nipple ducts and could be a challenge to the ductoscopy technology.
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ABSTRACT: Preclinical data has demonstrated the potential of the intraductal administration of chemotherapy for breast cancer prevention. Direct translation of this work has been stymied by the anatomical differences between rodents (one duct per teat) and women (5-9 ductal systems per breast). The objective of this Phase I study was to demonstrate the safety and feasibility of intraductal administration of chemotherapy drugs into multiple ducts within one breast in women awaiting mastectomy for treatment of invasive cancer. Thirty subjects were enrolled in this dose escalation study conducted at a single center in Beijing, China. Under local anesthetic, one of two chemotherapy drugs, carboplatin or pegylated liposomal doxorubicin (PLD), was administered into 5-8 ducts at 3 dose levels. Pharmacokinetic analysis demonstrated that carboplatin was rapidly absorbed into the bloodstream, while PLD, though more erratic, was absorbed after a delay. Pathological analysis showed marked effects on breast duct epithelium in ducts treated with either drug compared with untreated ducts. The study investigators had no difficulty in identifying or cannulating ducts except in one case with a central cancer with subareolar involvement. This study demonstrates the safety and feasibility of intraductal administration of chemotherapy into multiple ducts for the purpose of breast cancer prevention. This is an important step towards implementation of this strategy as a "chemical mastectomy", where the potential for carcinogenesis in the ductal epithelium is eliminated pharmacologically, locally, and without the need for surgery.Cancer Prevention Research 11/2012; 6(1). DOI:10.1158/1940-6207.CAPR-12-0228 · 4.89 Impact Factor
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ABSTRACT: How do infants extract milk during breast-feeding? We have resolved a century-long scientific controversy, whether it is sucking of the milk by subatmospheric pressure or mouthing of the nipple-areola complex to induce a peristaltic-like extraction mechanism. Breast-feeding is a dynamic process, which requires coupling between periodic motions of the infant's jaws, undulation of the tongue, and the breast milk ejection reflex. The physical mechanisms executed by the infant have been intriguing topics. We used an objective and dynamic analysis of ultrasound (US) movie clips acquired during breast-feeding to explore the tongue dynamic characteristics. Then, we developed a new 3D biophysical model of the breast and lactiferous tubes that enables the mimicking of dynamic characteristics observed in US imaging during breast-feeding, and thereby, exploration of the biomechanical aspects of breast-feeding. We have shown, for the first time to our knowledge, that latch-on to draw the nipple-areola complex into the infant mouth, as well as milk extraction during breast-feeding, require development of time-varying subatmospheric pressures within the infant's oral cavity. Analysis of the US movies clearly demonstrated that tongue motility during breast-feeding was fairly periodic. The anterior tongue, which is wedged between the nipple-areola complex and the lower lips, moves as a rigid body with the cycling motion of the mandible, while the posterior section of the tongue undulates in a pattern similar to a propagating peristaltic wave, which is essential for swallowing.Proceedings of the National Academy of Sciences 03/2014; DOI:10.1073/pnas.1319798111 · 9.81 Impact Factor
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ABSTRACT: In vitro and in vivo analyses differ between the number of milk ducts found in the lactating breast, and there is a lack of knowledge as to whether or not external factors in the mother or the child affect the number of ductal orifices. The aim of this study was to determine the number of milk duct orifices in vivo and to investigate the possible influence of variable parameters in mother and infant. Study design: Prospective clinical trial. In 98 breastfeeding women we investigated the nipple surface in order to identify the number of milk duct orifices using Marmet's manual milk expression technique. In addition mothers were interviewed on different parameters of birth and breastfeeding. Every nipple had 3.90 +/- 1.48 milk duct orifices on average. There was no significant difference between left and right breasts. The use of a breast pump in addition to breastfeeding did not have any effect on the number of ductal orifices.Multiparous women exhibited more ductal orifices (8.5 +/- 3.0) as compared to primipara (7.1 +/- 2.7). Boys were associated with significantly more ductal orifices in their mother's right breast (4.2 +/- 1.7) than girls (3.5 +/- 1.4). Furthermore boys were breastfed for longer per session. A shorter birth height of males correlated with more ductal orifices in left nipples. Fluid intake of mothers was associated with a higher number of ductal orifices. Restless infant behavior could not be explained by less milk duct orifices. Pain in the breast during breastfeeding did not have an influence on ductal orifices either. Psychological criteria, such as duration of maternity leave and total intended breastfeeding period, did not affect the number of orifices in the papilla mammaria of breasts during lactation. For the first time an in vivo investigation of the number of ductal orifices in lactating women was conducted non-invasively and associations with variables in the mother and the child, birth parameters in infants, and breastfeeding parameters in mothers and children were assessed. We conclude that the number of activated ductal orifices on the surface of the nipple is primarily associated with functional aspects.BMC Pregnancy and Childbirth 04/2014; 14(1):124. DOI:10.1186/1471-2393-14-124 · 2.15 Impact FactorThis article is viewable in ResearchGate's enriched formatRG Format enables you to read in context with side-by-side figures, citations, and feedback from experts in your field.