Infantile human labial glands: Distribution of aquaporins and claudins in the context of paracellular and transcellular pathways.

Human labial glands consist of saliva-secreting cells which are formed by serous and predominantly mucous glandular cells. The following excretory duct system converts the isotonic saliva into a hypotonic fluid. Liquids are transported across the membrane of epithelial cells by paracellular or transcellular mode of action. We studied aquaporins (AQP) and tight junction proteins in the endpieces and duct system of human labial glands of 3-5-month-old infants for the first time. AQP1, AQP3, and AQP5 represent the transcellular transport; tight junction proteins like claudin-1, - 3, - 4, and - 7 regulate the permeability of the paracellular pathway. Specimens of 28 infants were included in this study and analyzed histologically. AQP1 was present in myoepithelial cells and in endothelial cells of small blood vessels. AQP3 showed basolateral plasmamembrane localization in glandular endpieces. AQP5 was localized at the apical cytomembrane in serous and mucous glandular cells and at the lateral membrane in serous cells. Ducts remained unstained with the antibody to AQP1, AQP3, and AQP5. Claudin-1, - 3, - 4, and - 7 were expressed mainly in the lateral plasmamembrane of serous glandular cells. In the ducts, claudin-1, - 4, and - 7 were detected at the basal cell layer, claudin-7 also at the lateral cytomembrane. Our findings provide new insights into the localization of epithelial barrier components necessary for regulating saliva-modification in infantile labial glands.

Diversity of mucins in labial glands of infants.

Mucins as highly glycosylated proteins comprise multiple functions like protection, homeostasis, immune defense, cell signaling. Various epithelial tissues including glandular structures express different specific mucin types. We investigated labial salivary glands in infants for the occurrence of MUC1, MUC2, MUC3, MUC4, MUC5AC, MUC5B, and MUC7 by immunohistochemistry. MUC1 and MUC4 were detected in serous and ductal glandular cells, partially intensified at the apical plasma membrane. MUC3 was found in ductal glandular cells and in myoepithelial cells. MUC5B exhibited a mosaic expression pattern in mucous glandular endpieces. MUC2 and MUC7 were abundant in serous acini. Glandular structures were negative for MUC5AC. A comprehensive study of specific mucins in labial salivary glands of infants was presented for the first time. As a representative of the minor salivary glands, labial glands are, due to their localization, directly exposed to environmental influences. The distribution of a broad spectrum of mucins in infantile labial glands indicates their importance early in human development to sustain oral health.

Evaluation of Tissue-engineered Skin on Base of Human Amniotic Membrane for Wound Healing.

Human amniotic membranes (hAMs) have shown promising results in recent studies aimed at improving wound healing through several mechanisms. We wanted to investigate its properties as a scaffold by adding autologous cells to treat full-thickness skin defects and hypothesized that recultivated hAM would show an even improved wound healing by accelerating the epidermal closure of the wound. METHODS: In an air-liquid cell culture, we cultivated autologous keratinocytes and fibroblasts on the hAM until a mostly keratinized surface was achieved. These hAM, de-epithelialized hAM, native hAM with remaining allogenous cells, and negative controls were compared in the treatment of circular 30 × 30 mm2 full-thickness skin defects in 4 groups of 6 rats with one wound each. We evaluated the wound contraction every 10 days until wound closure, the macroscopic scar appearance on the Vancouver Scar Scale and the qualitative histological properties of the scar regarding morphology and continuity of the basement membrane. RESULTS: Rats treated with de-epithelialized hAM showed more extent wound contraction (P < 0.001) than the other 3 groups, which did not differ significantly compared with the control group (P > 0.05). Vancouver Scar Scale showed no significantly statistical differences between the 4 groups (P = 0.46). The scar structure of all rats showed similar morphologies, the only difference being the absence of a basement membrane in the negative controls compared with the groups treated with hAM. CONCLUSION: The rats treated with hAM showed no improved wound healing but a tendency toward a more prominent basement membrane in the resulting scar.

Immunolocalization of Surfactant Proteins SP-A, SP-B, SP-C, and SP-D in Infantile Labial Glands and Mucosa.

Surfactant proteins in different glandular structures of the oral cavity display antimicrobial activity for protection of invading microorganisms. Moreover, they are involved in lowering liquid tension in fluids and facilitate secretion flows. Numerous investigations for studying the occurrence of surfactant proteins in glandular tissues were performed using different methods. In the oral cavity, minor salivary glands secrete saliva continuously for the maintenance of a healthy oral environment. For the first time, we could show that infantile labial glands show expression of the surfactant proteins (SP) SP-A, SP-B, SP-C, and SP-D in acinar cells and the duct system in different intensities. The stratified squamous epithelium of the oral mucosa revealed positive staining for SPs in various cell layers.

Image analysis of immune cell patterns in the human mammary gland during the menstrual cycle refines lymphocytic lobulitis.

PURPOSE: To improve microscopic evaluation of immune cells relevant in breast cancer oncoimmunology, we aim at distinguishing normal infiltration patterns from lymphocytic lobulitis by advanced image analysis. We consider potential immune cell variations due to the menstrual cycle and oral contraceptives in non-neoplastic mammary gland tissue. METHODS: Lymphocyte and macrophage distributions were analyzed in the anatomical context of the resting mammary gland in immunohistochemically stained digital whole slide images obtained from 53 reduction mammoplasty specimens. Our image analysis workflow included automated regions of interest detection, immune cell recognition, and co-registration of regions of interest. RESULTS: In normal lobular epithelium, seven CD8[Formula: see text] lymphocytes per 100 epithelial cells were present on average and about 70% of this T-lymphocyte population was lined up along the basal cell layer in close proximity to the epithelium. The density of CD8[Formula: see text] T-cell was 1.6 fold higher in the luteal than in the follicular phase in spontaneous menstrual cycles and 1.4 fold increased under the influence of oral contraceptives, and not co-localized with epithelial proliferation. CD4[Formula: see text] T-cells were infrequent. Abundant CD163[Formula: see text] macrophages were widely spread, including the interstitial compartment, with minor variation during the menstrual cycle. CONCLUSIONS: Spatial patterns of different immune cell subtypes determine the range of normal, as opposed to inflammatory conditions of the breast tissue microenvironment. Advanced image analysis enables quantification of hormonal effects, refines lymphocytic lobulitis, and shows potential for comprehensive biopsy evaluation in oncoimmunology.

An Immunohistochemical Study on the Role of Oxidative and Nitrosative Stress in Irradiated Skin.

BACKGROUND/AIM: The effects of ionizing radiation through the generation of free radicals, reactive aldehydes, and other oxidative and nitrosative by-products account for skin injuries as side effects of radiation therapy (RT). This study aims to identify cellular pathways in oxidative and nitrosative stress in irradiated skin using well-established marker proteins in an immunohistochemical analysis. MATERIALS AND METHODS: Tissue specimens of 51 patients were obtained during operative access to the neck. Twenty patients (39.2%) received RT prior to the surgical intervention. Immunohistochemical analysis of stable degradation products of reactive oxygen and nitrogen species (RONS), 3-nitrotyrosine, 8-isoprostane, phosphorylated AKT (p-AKT), and phosphorylated extracellular signal-regulated kinase (p-ERK) was performed in specimens which were exposed to RT and those without a history of RT. RESULTS: Immunohistochemical staining showed a significantly increased expression of nitrotyrosine in superficial and basal epidermal regions of interest (ROI), p-AKT in all epidermal ROI, and p-ERK in all the investigated epidermal and dermal ROI, as well as in an overall analysis. No significance could be detected in immunostaining against isoprostane. DISCUSSION: This study summarizes the influence of RONS in RT. Moreover, a detailed histological analysis was able to identify epidermal ROI as a main starting point of RONS in irradiated skin. Even though the role of RONS in high-dose therapeutic radiation remains a subject for further research, these data underlines the crucial role of RONS in high-dose radiation.

Labial Salivary Glands in Infants: Histochemical Analysis of Cytoskeletal and Antimicrobial Proteins.

Human labial glands secrete mucous and serous substances for maintaining oral health. The normal microbial flora of the oral cavity is regulated by the acquired and innate immune systems. The localization and distribution of proteins of the innate immune system were investigated in serous acinar cells and the ductal system by the method of immunohistochemistry. Numerous antimicrobial proteins could be detected in the labial glands: ß-defensin-1, -2, -3; lysozyme; lactoferrin; and cathelicidin. Cytoskeletal components such as actin, myosin II, cytokeratins 7 and 19, α- and ß-tubulin were predominantly observed in apical cell regions and may be involved in secretory activities.

An expression analysis of markers of radiation-induced skin fibrosis and angiogenesis in wound healing disorders of the head and neck.

BACKGROUND: Radiation-induced fibrosis (RIF) is one of the severe long-term side effects of radiation therapy (RT) with a crucial impact on the development of postoperative wound healing disorders (WHD). The grades of fibrosis vary between mild to severe depending on individual radiosensitivity. In this study, we have investigated the molecular pathways that influence RIF and have correlated data from immunohistochemistry (IHC) for von -Willebrand Factor (vWF) and from Real-Time Polymerase Chain Reaction (RT-PCR) concerning markers such as Transforming Growth Factor (TGF)-ß 1, and vWF, with clinical data concerning the occurrence of WHD during follow-up. METHODS: Expression profiles of the genes encoding TGF-ß 1, vWF, and α-procollagen (PC) were analyzed, by RT-PCR, in specimens from patients with (n = 20; 25.6 %) and without (n = 58; 74.4 %) a history of previous RT to the head and neck. Moreover, IHC against vWF was performed. Clinical data on the occurrence of cervical WHDs were analyzed and correlated. RESULTS: A statistically significant increase in the expression profiles of α-PC and TGF-ß 1 was observed in previously irradiated skin samples (occurrence of RT >91 days preoperatively). vWF showed a statistically significant increase in non-irradiated tissue. Moreover, analysis of expression profiles in patients with and without WHDs during follow-up was performed. IHC showed a reduced amount of vessels and structural changes in epidermal tissue post-RT. CONCLUSIONS: The expression of markers of fibrosis and angiogenesis was analyzed in order to gain insight into molecular pathways that account for structural changes in irradiated skin and that eventually lead to WHDs. The results are congruent with reports from the literature and are a possible starting point for further research, as anti-TGF-ß 1 treatment, for example, could represent new therapeutic opportunities in the management of previously irradiated patients.

Evaluation of human amniotic membrane as a wound dressing for split-thickness skin-graft donor sites.

Human amniotic membrane (HAM) has been used as a biomaterial in various surgical procedures and exceeds some qualities of common materials. We evaluated HAM as wound dressing for split-thickness skin-graft (STSG) donor sites in a swine model (Part A) and a clinical trial (Part B). Part A: STSG donor sites in 4 piglets were treated with HAM or a clinically used conventional polyurethane (PU) foil (n = 8 each). Biopsies were taken on days 5, 7, 10, 20, 40, and 60 and investigated immunohistochemically for alpha-smooth muscle actin (αSMA: wound contraction marker), von Willebrand factor (vWF: angiogenesis), Ki-67 (cell proliferation), and laminin (basement membrane integrity). Part B: STSG donor sites in 45 adult patients (16 female/29 male) were treated with HAM covered by PU foam, solely by PU foam, or PU foil/paraffin gauze (n = 15 each). Part A revealed no difference in the rate of wound closure between groups. HAM showed improved esthetic results and inhibitory effects on cicatrization. Angioneogenesis was reduced, and basement membrane formation was accelerated in HAM group. Part B: no difference in re-epithelialization/infection rate was found. HAM caused less ichor exudation and less pruritus. HAM has no relevant advantage over conventional dressings but might be a cost-effective alternative.

Evaluation of intraoperative cytological assessment of bone resection margins in patients with oral squamous cell carcinoma.

BACKGROUND: Frozen sections are routinely applied to control for adequate resection margins. In cases in which carcinoma infiltrates bone, the intraoperative microscopic assessment of bone margins remains challenging due to technical difficulties to section native bone. The objective of the current study was to evaluate an intraoperative cytological approach to control bone resection margins in patients with bone-infiltrating oral squamous cell carcinomas. METHODS: A total of 174 cytological preparations obtained from bone margins of bone-infiltrating oral squamous cell carcinomas (28 patients) were assessed intraoperatively and compared with the corresponding histological findings. In a validation cohort (45 patients) the intraoperative cytological assessment of bone resection margins (ICAB) (104 margins) was evaluated as a diagnostic tool for routine clinical application. RESULTS: In the first patient cohort, the ICAB revealed 95.3% sensitivity and 96% specificity. The results provided an accuracy of 95.7% with a significant correlation noted between cytological and histological results (κ, 0.91; P < .001), and a positive predictive value and negative predictive value of 93.8% and 96.9%, respectively. In the validation cohort, ICAB revealed 80% sensitivity and 98.9% specificity with 98% accuracy. There was a significant correlation found between cytological and histological results (κ, 0.91; P < .001), providing a positive predictive value and negative predictive value of 80% and 98%, respectively. ICAB could predict final resection status at bone margins with 80% sensitivity and 97.5% specificity. A significant correlation was found between the cytological and histological resection status at bone margins (κ, 0,75; P < .001). CONCLUSIONS: ICAB could supplement intraoperative frozen sections of soft tissue margins as a standard procedure to control for adequate resection at bone margins.

Immunolocalization of antimicrobial and cytoskeletal components in the serous glands of human sinonasal mucosa.

Secretory cells in the seromucous glands of paranasal sinuses secrete antibacterial proteins for innate immune mucosal integrity. We studied the localization of antimicrobial and cytoskeletal components of the human seromucous glands and respiratory epithelium of the maxillary sinus and the ethmoidal cells by immunohistochemical methods. The presence of a variety of defense proteins such as lysozyme, lactoferrin, cathelicidin, and defensin-1, -2, -3 point to a crucial role in the immune defense for the respiratory tract. Cytoskeletal proteins such as actin, myosin 2, cytokeratin 7 and 19, α- and ß-tubulin, investigated for the first time in glands of paranasal sinuses, showed a stronger expression at the apical and lateral cell membrane. The localization of the cytoskeletal proteins might point to their participation in exocrine secretory processes and stabilizing effects.

Ischemia-reperfusion-induced unmeasured anion generation and glycocalyx shedding: sevoflurane versus propofol anesthesia.

INTRODUCTION: Vascular leakage after ischemia-reperfusion (IR) is largely attributed to the destruction of the endothelial barrier and its associated negatively charged glycocalyx. In vitro, sevoflurane attenuates these changes. Therefore, we compared sevoflurane with propofol with regard to the protection of the glycocalyx and the release of negatively charged substances in vivo. METHODS: After surgical preparation under midazolam-fentanyl, nine pigs each received either propofol or sevoflurane. Ischemia of 90 min was induced by a balloon catheter in the thoracic aorta. After 120 min of reperfusion, the anesthetics were changed back to midazolam-fentanyl. Five animals, each without aortic occlusion, served as time controls. Blood electrolyte parameters were measured, from which the strong ion gap (SIG) was calculated. Serum heparan sulfate concentrations and immunohistology served as a marker of glycocalyx destruction. RESULTS: Immediately after reperfusion, SIG increased significantly only in the propofol group (+6.7 mEq/l versus baseline; p < .05), remaining stable in sevoflurane and both time-controlled groups. Initially, heparan sulfate concentration increased comparably in both experimental groups, but after 120 min, it became stable in sevoflurane-anesthetized animals, while increasing further in the propofol group (p < .05). CONCLUSIONS: Unmeasured anions, predictive of negative outcome in previous studies, did not increase significantly in sevoflurane-anesthetized animals. Additionally, there was less heparan sulfate shedding over time, signaling less destruction of the glycocalyx. Therefore, in this in-vivo situation, sevoflurane proves to be superior to propofol in protecting the endothelium from IR injury.

Amniotic membrane as part of a skin substitute for full-thickness wounds: an experimental evaluation in a porcine model.

BACKGROUND: We evaluated the use of human amniotic membrane (HAM) as a graft material for the treatment of iatrogenic full-thickness (FT) skin wounds in a porcine model with a view to reducing donor site morbidity in free flap transfer. METHODS: Forty experimental FT-wounds were covered with an autologous split-thickness skin graft (STSG) alone or in combination with a mono- or multilayer HAM or Integra(®). Untreated wounds served as controls. Clinical evaluation and biopsy-sampling for histological and immunohistochemical staining with von-Willebrand-factor (vWF) antibody, laminin antibody, Ki-67 antibody, and smooth muscle actin (αSMA) antibody were performed on days 5, 7, 10, 20, 40, and 60 after surgical intervention. RESULTS: Considerable disparities in the estimated criteria were observed between the various treatment groups of the FT-wounds. The use of HAM was found to have an accelerating impact on re-epithelialization. The multilayered amnion membrane showed better results than the Integra(®) and monolayer technique in terms of contraction rate, inflammation, and scarring and seemed useful as a dermal substitute in FT-wounds giving comparable results to STSG coverage alone. CONCLUSIONS: This study demonstrates the successful application of HAM as part of a skin substitute in FT-wounds in minipigs. The results offer promise as a simple and effective technique for the application of multilayer HAM in iatrogenic human skin defects and the acceleration of wound healing.

Quantitative comparison of the expression of antimicrobial peptides in the oral mucosa and extraoral skin.

Antimicrobial peptides (AMP) defend epithelial surfaces against pathological micro-organisms. We know of no comparison of their expression between the oral mucosa and extraoral epithelium, but knowledge of differences in their quantities is of interest, possibly as a starting point for new treatments. Expression of AMP human beta-defensin (hBD)-1/-2/-3 and psoriasin in the oral mucosa and extraoral epithelium of the head and neck were measured by real-time polymerase chain reaction (RT-PCR) (n=14), immunohistochemistry (n=6), and western blot (n=8). RT-PCR showed that all the genes investigated were expressed significantly more in the oral mucosa than in the skin (hBD-1: p=0.002; hBD-2: p=0.006; hBD-3: p=0.035; psoriasin: p=0.02). Immunohistochemistry and western blot showed differential concentrations of proteins: hBD-2 (p=0.021) and hBD-3 (p=0.043) were pronounced in the oral mucosa, whereas psoriasin was raised in the extraoral skin (p=0.021). There was no difference in protein concentrations for hBD-1 (p=0.08). The observed differences in the expression of AMP may be important for new treatments such as topical application of AMP derivatives.

Human ß-defensins and psoriasin/S100A7 expression in salivary glands: anti-oncogenic molecules for potential therapeutic approaches.

BACKGROUND: Host defence peptides (HDPs), including human ß-defensins (hBDs) and psoriasin/S100A7, exert antimicrobial and immunoregulatory functions of the innate defense system. In addition to these functions, the search for cancer biomarkers has identified HDPs as playing a potential role in both tumor suppression and oncogenesis. Although HDPs are highly expressed in salivary glands, their role as molecules for potential diagnostic and therapeutic approaches has not yet been analyzed. OBJECTIVE: The aim of the present study was to investigate whether expression levels of putative pro- or anti-oncogenic hBDs, including hBD-1, -2, -3, and psoriasin/S100A7, are altered in salivary gland tumor tissue as potential targets for molecular-based therapeutic approaches. METHODS: We analyzed the expression levels of hBD-1, -2, -3, and psoriasin/S100A7 by quantitative real-time polymerase chain reaction (qrt-PCR) and immunohistochemistry in a case control study by comparing salivary gland tumor samples relative to healthy control specimens from 58 patients. Expression level analysis of hBD-1, -2, -3, and psoriasin/S100A7 by qrt-PCR was normalized to the endogenous 18S rRNA expression levels. RESULTS: The results demonstrate the significant downregulation of hBD-1 (p < 0.001), hBD-2 (p = 0.003), hBD-3 (p = 0.002), and psoriasin/S100A7 (p = 0.003) mRNA in human salivary gland tumors compared with healthy control specimens. Protein expression levels of hBD-1, -2, -3, and psoriasin/S100A7 in salivary gland tumor tissue were strongly reduced compared with healthy control specimens. CONCLUSION: The data indicates a putative role of the innate defense system in salivary gland tumor formation. The identification of immunoregulatory molecules as diagnostic biomarkers or therapeutic targets could provide new approaches for molecular-based diagnostic and therapeutic support to treat salivary gland tumors as well as other malignancies. We suggest that HDPs should be taken into consideration for use in molecular-based therapeutic approaches.

The human submandibular gland: immunohistochemical analysis of SNAREs and cytoskeletal proteins.

Submandibular acinar glands secrete numerous proteins such as digestive enzymes and defense proteins on the basis of the exocrine secretion mode. Exocytosis is a complex process, including a soluble NSF attachment protein receptor (SNARE)-mediated membrane fusion of vesicles and target membrane and the additional activation of cytoskeletal proteins. Relevant data are available predominantly for animal salivary glands, especially of the rat parotid acinar cells. The authors investigated the secretory molecular machinery of acinar (serous) cells in the human submandibular gland by immunohistochemistry and immunofluorescence and found diverse proteins associated with exocytosis for the first time. SNAP-23, syntaxin-2, syntaxin-4, and VAMP-2 were localized at the luminal plasma membrane; syntaxin-2 and septin-2 were expressed in vesicles in the cytoplasm. Double staining of syntaxin-2 and septin-2 revealed a colocalization on the same vesicles. Lactoferrin and α-amylase served as a marker for secretory vesicles and were labeled positively together with syntaxin-2 and septin-2 in double-staining procedures. Cytoskeletal components such as actin, myosin II, cofilin, and profilin are concentrated at the apical plasma membrane of acinar submandibular glands. These observations complement the understanding of the complex exocytosis mechanisms.

Perspectives in microvascular fluid handling: does the distribution of coagulation factors in human myocardium comply with plasma extravasation in venular coronary segments?

BACKGROUND: Heterogeneity of vascular permeability has been suggested for the coronary system. Whereas arteriolar and capillary segments are tight, plasma proteins pass readily into the interstitial space at venular sites. Fittingly, lymphatic fluid is able to coagulate. However, heart tissue contains high concentrations of tissue factor, presumably enabling bleeding to be stopped immediately in this vital organ. The distribution of pro- and anti-coagulatively active factors in human heart tissue has now been determined in relation to the types of microvessels. METHODS AND RESULTS: Samples of healthy explanted hearts and dilated cardiomyopathic hearts were immunohistochemically stained. Albumin was found throughout the interstitial space. Tissue factor was packed tightly around arterioles and capillaries, whereas the tissue surrounding venules and small veins was practically free of this starter of coagulation. Thrombomodulin was present at the luminal surface of all vessel segments and especially at venular endothelial cell junctions. Its product, the anticoagulant protein C, appeared only at discrete extravascular sites, mainly next to capillaries. These distribution patterns were basically identical in the healthy and diseased hearts, suggesting a general principle. CONCLUSIONS: Venular extravasation of plasma proteins probably would not bring prothrombin into intimate contact with tissue factor, avoiding interstitial coagulation in the absence of injury. Generation of activated protein C via thrombomodulin is favored in the vicinity of venular gaps, should thrombin occur inside coronary vessels. This regionalization of distribution supports the proposed physiological heterogeneity of the vascular barrier and complies with the passage of plasma proteins into the lymphatic system of the heart.

Human axillary apocrine glands: proteins involved in the apocrine secretory mechanism.

The apocrine secretory mechanism is a mode of secretion by which the apical part of the cell cytoplasm is pinched off, which leads to the formation of an aposome. The distinct mechanism of formation and decapitation of the aposome is not well investigated. Only few proteins are known that are involved in this secretory mechanism. We studied the human axillary apocrine gland and looked at proteins associated with cytokinesis, a process that is comparable to the pinching-off mechanism of apocrine glandular cells. By immunohistochemistry, we detected actin, myosin II, cytokeratin 7 and 19, α- and ß-tubulin, anillin, cofilin, syntaxin 2, vamp8/endobrevin and septin 2. In highly active glandular cells, these proteins are located at the base of the apical protrusion when the aposome is in the process of being released or are concentrated in the cap of the apical protrusion. These findings demonstrate new insights on apocrine secretory mechanisms and point to similarities to the terminal step of cytokinesis, which is regulated by a SNARE-mediated membrane fusion event.

Radiofrequency ablation in breast tissue: experimental study for evaluation of radiofrequency effects in the bovine udder and review of the literature.

PURPOSE: To investigate the radiofrequency (RF) effects on the nonlactating and lactating ex vivo bovine udder as a model for normal breast tissue. MATERIALS AND METHODS: RF ablation in three lactating and three nonlactating ex vivo bovine udders (ie, six udders) was performed. The opening of the electrodes was 3 cm. The temperature was applied in 10 degrees C increasing steps between 60 degrees C and 100 degrees C and each temperature was maintained for 15 minutes. The experiment was repeated three times for each temperature step in the lactating and nonlactating udder. Resected specimens were assessed histologically. The maximum diameter of the ablation zone and maximum width of the transition zone with respect to the temperature applied were measured. RESULTS: In the nonlactating tissue, there was a correlation of the temperature and diameter of tissue damage. There was a narrow transition zone of 0.10 cm in all cases except at 100 degrees C, when it was 0.17 cm. In the lactating udder, no correlation was seen. The transition zone was not well visualized at temperatures less than 80 degrees C, ranging in overall size between 0.15 cm and 0.20 cm. CONCLUSIONS: The results of the study, with clear demarcation of the ablation zones and transition zones in the normal breast tissue, support the potential of breast thermal ablation as a viable treatment for further study. Lactating tissue does not seem ideal for thermal ablation. The discrepancy of the extent of ablation and the length of the electrodes is an important finding in this study. Further in vivo studies in normal glandular tissue and tumor are necessary.