PubMed · 8043721
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H Böhrer, M Goerig. 1994. [Simple anesthesia procedures and aids].. https://doi.org/10.1055/s-2007-996713
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BACKGROUND: In breast-cancer research, we lack reproducible non-invasive access to breast tissue. Breast cancer is thought to start in the lining of the milk duct or lobule. We have had no direct access to this area other than in tissue removed surgically or by fine-needle aspiration. Our objective was to explore an intraductal approach to studying breast cancer and precancerous changes by duct cannulation and endoscopy. METHODS: In this pilot study, women in a university hospital were asked to participate. Nine patients with previously diagnosed ductal carcinoma-in-situ (DCIS) or invasive breast cancer who were about to undergo mastectomy under general anaesthesia agreed. After the patient was asleep but before the operation, we spent 15 minutes cannulating their ducts, obtaining washings, and attempting endoscopy. The ducts that had been cannulated were marked by instillation of dye or other materials, the nipple was sutured shut, and the mastectomy proceeded as planned. The mastectomy specimen underwent extensive histopathological examination. FINDINGS: We were successful in intraductal cannulation and endoscopy in seven of the nine patients. In five of the nine, we obtained epithelial cells in the washings. In one the cells were consistent with proliferative disease, in three there was atypical epithelium, and in one there was frank DCIS. With several different contrast materials injected into separate duct orifices, DCIS was confined to a single duct system. INTERPRETATION: We found that the intraductal approach is feasible for the study of the early changes of breast cancer Technical difficulties include identification of the breast duct orifices, determining the distensibility of the duct, and developing a reliable technique to obtain washings.
1. Neuropeptide Y (NPY) has been reported to enhance diuresis and natriuresis in anaesthetized rats although it is a potent renal vasoconstrictor in vitro in vivo in several species. Therefore, we have investigated anaesthetized rats to see whether reduction in renal blood flow (RBF) and enhancement of diuresis and natriuresis can occur concomitantly, and how diuresis and natriuresis might be enhanced despite reduced RBF. 2. Systemic or intrarenal NPY infusion (0.03-3 micrograms kg-1 min-1) had only a small effect on mean arterial pressure (maximal increase 15-20 mmHg) and heart rate (maximal decrease 30 beats min-1) but dose-dependently reduced RBF (maximal peak reduction 3 ml min-1) Endogenous creatinine clearance was not significantly altered. 3. In anaesthetized rats systemic infusion of 1 or 3 micrograms kg-1 min-1 NPY enhanced urine formation and sodium and calcium excretion by a maximum of 110, 110 and 45%, respectively, but did not alter potassium excretion. Enhancement of diuresis was also detectable in conscious rats. 4. The diuretic and natriuretic effects of systemically infused NPY were at least partly maintained in rats with decapsulated kidneys and in rats where NPY-induced increase of renal perfusion pressure was excluded mechanically by an adjustable clamp placed on the abdominal aorta. 5. Intrarenal infusion of 0.3 or 1 microgram kg-1 min-1 NPY reduced RBF to a greater extent than systemic infusion (maximal peak reduction 4 ml min-1) but caused a smaller enhancement or even a reduction of urine formation and sodium excretion. 6. We conclude that systemic infusion of NPY reduces RBF by a direct effect on the renal vasculature. Systemic NPY infusion enhances urine formation and sodium and calcium excretion. This occurs independently (at least in part) of pressure natriuresis by formation and/or release of an extrarenal factor which might act on distal tubules and/or collecting ducts.
Sympathetic neurones supplying the submandibular salivary gland innervate blood vessels, secretory and myoepithelial cells. Here we examined whether these functionally different sympathetic neurones show distinct reflex response patterns. In anaesthetized rats, single unit activity was recorded from postganglionic axons projecting to the gland. Neurones were tested for their responses to stimulation of baroreceptors, cutaneous nociceptors and cold receptors and to gustatory stimuli applied to the tongue. Respiratory modulation was also analysed. Only a few postganglionic neurones identified electrically (5-10%) were spontaneously active. They were excited by noxious and cold stimuli, inhibited by baroreceptor stimulation and exhibited respiratory modulation. None of the units responded to gustatory stimuli. Thus, in anaesthetized rats spontaneously active sympathetic neurones supplying the submandibular gland behave like vasoconstrictor neurones. Sympathetic neurones with other functions are probably silent.