Comparative Morphology of the Lungs and Skin of two Anura, Pelophylax nigromaculatus and Bufo gargarizans.

The lungs and skin are important respiratory organs in Anura, but the pulmonary structure of amphibians remains unclear due to the lack of a suitable procedure. This study improved the procedure used for fixing lungs tissues and used light microscopy, transmission electron microscopy and scanning electron microscopy to reveal the differences in the lung and skin morphologies between Pelophylax nigromaculatus (P. nigromaculatus) and Bufo gargarizans (B. gargarizans). In P. nigromaculatus and B. gargarizans, the cystic lungs comprise a continuous outer pulmonary wall on which primary, secondary, and tertiary septa attach, and a number of regular lattices form from raised capillaries and the pulmonary epithelium on the surfaces of the pulmonary wall and septa. Each lattice in P. nigromaculatus consists of several elliptical sheets and flat bottom, and the septa are distributed with denser sheets and have a larger stretching range than the pulmonary wall. The lattice in B. gargarizans consists of thick folds and an uneven bottom with several thin folds, and the septa have more developed thick and thin folds than the pulmonary wall. However, the density of the pulmonary microvilli, the area of a single capillary, the thicknesses of the blood-air barrier, pulmonary wall and septum, and the lung/body weight percentage obtained for B. gargarizans were higher than those found for P. nigromaculatus. In P. nigromaculatus, the dorsal skin has dense capillaries and a ring surface structure with mucus layer on the stratum corneum, and the ventral skin is slightly keratinized. In B. gargarizans, the stratum corneum in both the dorsal and ventral skins is completely keratinized. A fine ultrastructure analysis of P. nigromaculatus and B. gargarizans revealed that the pulmonary septa are more developed than the pulmonary walls, which means that the septa have a stronger respiratory function. The more developed lungs are helpful for the adaptation of B. gargarizans to drought environments, whereas P. nigromaculatus has to rely on more vigorous skin respiration to adapt to a humid environment.

Validation of noninvasive focal depth measurements to determine epithelial thickness of the vaginal wall.

OBJECTIVE: This study investigates whether noninvasive focal depth (FD) measurements correlate with vaginal wall epithelial thickness (ET). If FD accurately reflects ET of the vaginal wall, this would allow noninvasive longitudinal assessment of (newly developed) treatment modalities aiming to increase ET, without the need for invasive biopsies. METHODS: Fourteen women, median age 62 years (inter quartile ranges: 57-65), undergoing vaginal prolapse surgery because of anterior and/or posterior compartment pelvic organ prolapse were included. We used the CytoCam, a handheld video microscope based on incident dark field imaging, and performed FD measurements of the vaginal wall before surgery. Histology was performed on tissue that was removed during the surgical procedure, and ET was measured in stained sections. We compared ET with FD interindividually, and determined the expected linear correlation and agreement between the two measurements. RESULTS: Seventeen ET measurements (mean 125 µm ±â€Š38.7, range 48-181 µm) were compared with 17 FD measurements (mean 128 µm ±â€Š34.3, range 68-182 µm). The lineair correlation between the two measurements was strong (r = 0.902, P < 0.01). Bland-Altman analysis demonstrated a mean difference of 13.5 µm when comparing ET to FD. CONCLUSIONS: The results demonstrate good agreement between ET and FD measurements. We consider the mean difference demonstrated with Bland-Altman analysis acceptable for these measurements. This suggests that FD accurately reflects ET, which further supports the use of FD to measure ET of the vaginal wall. For a complete assessment of the vaginal wall, FD measurements are preferably combined with the assessment of vaginal angioarchitecture.

The Spectrum of Morphologic Alterations Associated With Infarction in Endometrial Polyps: A Report of 41 Cases.

The authors describe the clinicopathologic features of a group of endometrial polyps that exhibited large areas of infarction, to highlight the spectrum of morphologic alterations that may occur in this setting, including moderate cytologic atypia in a subset. Forty-one infarcted endometrial polyps, classified as such based on the presence therein of confluent zones of stromal necrosis and/or sharply demarcated zones of paucicellular to acellular stromal hyalinization, were assembled from multiple institutions. All were diagnosed in biopsies, polypectomies, or curettages. The morphologic profile of the epithelium associated with the infarcted zones was compared with those of a control group of 40 consecutive noninfarcted polyps. The patients with infarcted polyps ranged in age from 23 to 94 yr and were significantly older than the control group patients (mean ages, 60.8 vs. 49 yr respectively; P=0.02). The most common architectural alteration in infarcted polyps was a distinctive cellular tufting or pseudopapillary change, possibly representing an exuberant iteration of papillary syncytial change, which was seen in 39% of cases. Among the features that were significantly more prevalent in infarcted polyps than the control group were grade 2 pleomorphism (i.e., a 2-3-fold variation in nuclear size and/or shape) (37% vs. 2.5%, respectively; P=0.00029), cellular syncytia (44% vs. 15%; P=0.069), vesicular chromatin greater than background glands (56% vs. 7.5%; P <0.0001), hobnail cells (27% vs. 0%; P=0.0004), clear cells (12% vs. 0%; P=0.055), and eosinophilic cells (56% vs. 15%; P=0.000115). The 2 groups were not significantly different regarding mitotic index and a variety of other morphologic variables. Irrespective of morphology, epithelia within the infarcted zones at least focally showed a core immunophenotype (p53-wild type, p16-diffusely positive; low proliferative index) that was essentially identical to the phenotype displayed by foci of papillary syncytial metaplasia unassociated with polyps in a 10-case comparison group. None of the 34 patients with follow-up information has subsequently been diagnosed with a uterine neoplasm. In summary, infarcted endometrial polyps frequently display a spectrum of cytoarchitecturally atypical epithelial changes. These pseudoneoplastic alterations are most likely degenerative and/or metaplastic in nature.

Thymidine phosphorylase and angiogenesis in early stage esophageal squamous cell carcinoma.

BACKGROUND: The relationship between thymidine phosphorylase (TP) and angiogenesis at the early stage of esophageal squamous cell carcinoma has been unclear. METHODS: Using 14 samples of normal squamous epithelium, 11 samples of low-grade intraepithelial neoplasia, and 64 samples of superficial esophageal cancer, microvessel density (MVD) was estimated using immunostaining for CD34 and CD105. TP expression was also evaluated in both cancer cells and stromal monocytic cells (SMCs). We then investigated the correlation between MVD and TP expression in both cancer cells and SMCs. RESULTS: On the basis of the above parameters, MVD was significantly higher in cancerous lesions than in normal squamous epithelium. In terms of CD34 and CD105 expression, MVD showed a gradual increase from normal squamous epithelium, to low-grade intraepithelial neoplasia, and then to M1 and M2 cancer, and M3 or deeper cancer. M1 and M2 cancer showed overexpression of TP in both cancer cells and SMCs. There was no significant correlation between TP expression in cancer cells and MVD estimated from CD34 (rS = 0.16, P = 0.21) or CD105 (rS = 0.05, P = 0.68) expression. Significant correlations were found between TP expression in SMCs and CD34-related (rS = 0.46, P < 0.001) and CD105-related (rS = 0.34, P < 0.01) MVD. In M3 or deeper cancers, there were no significant correlations between TP expression in cancer cells or SMCs and venous invasion, lymphatic invasion, and lymph node metastasis. CONCLUSION: TP expression is activated in both cancer cells and stromal monocytic cells at the very early stage of ESCC progression. TP expression in SMCs, rather than in cancer cells, is significantly correlated with angiogenesis.

Sex differences and effects of oestrogen in rat gastric mucosal defence.

AIM: To evaluate sex differences and the effects of oestrogen administration in rat gastric mucosal defence. METHODS: Sex differences in gastric mucus thickness and accumulation rate, absolute gastric mucosal blood flow using microspheres, the integrity of the gastric mucosal epithelium in response to a chemical irritant and the effects of oestrogen administration on relative gastric mucosal blood flow in an acute setting was assessed in an in vivo rat experimental model. Subsequently, sex differences in the distribution of oestrogen receptors and calcitonin gene related peptide in the gastric mucosa of animals exposed to oestrogen in the above experiments was evaluated using immunohistochemistry. RESULTS: The absolute blood flow in the GI-tract was generally higher in males, but only significantly different in the corpus part of the stomach (1.12 ± 0.12 mL/min•g in males and 0.51 ± 0.03 mL/min•g in females) (P = 0.002). After removal of the loosely adherent mucus layer the thickness of the firmly adherent mucus layer in males and females was 79 ± 1 µm and 80 ± 3 µm respectively. After 60 min the mucus thickness increased to 113 ± 3 µm in males and 121 ± 3 µm in females with no statistically significant difference seen between the sexes. Following oestrogen administration (0.1 followed by 1 µg/kg•min), mean blood flow in the gastric mucosa decreased by 31% [68 ± 13 perfusion units (PFU)] in males which was significantly different compared to baseline (P = 0.02). In females however, mean blood flow remained largely unchanged with a 4% (5 ± 33 PFU) reduction. The permeability of the gastric mucosa increased to a higher level in females than in males (P = 0.01) after taurocholate challenge. However, the calculated mean clearance increase did not significantly differ between the sexes [0.1 ± 0.04 to 1.1 ± 0.1 mL/min•100 g in males and 0.4 ± 0.3 to 2.1 ± 0.3 mL/min•100 g in females (P = 0.065)]. There were no significant differences between 17ß-Estradiol treated males (mean ratio of positive staining ± SEM) (0.06 ± 0.07) and females (0.11 ± 0.11) in the staining of ERα (P = 0.24). Also, there were no significant differences between 17ß-Estradiol treated males (0.18 ± 0.21) and females (0.06 ± 0.12) in the staining of ERß (P = 0.11). Finally, there were no significant differences between 17ß-Estradiol treated males (0.04 ± 0.05) and females (0.11 ± 0.10) in the staining of CGRP (P = 0.14). CONCLUSION: Gastric mucosal blood flow is higher in male than in female rats and is reduced in male rats by oestrogen administration.

The biomechanical properties of an epithelial tissue determine the location of its vasculature.

An important question is how growing tissues establish a blood vessel network. Here we study vascular network formation in pancreatic islets, endocrine tissues derived from pancreatic epithelium. We find that depletion of integrin-linked kinase (ILK) in the pancreatic epithelial cells of mice results in glucose intolerance due to a loss of the intra-islet vasculature. In turn, blood vessels accumulate at the islet periphery. Neither alterations in endothelial cell proliferation, apoptosis, morphology, Vegfa expression and VEGF-A secretion nor 'empty sleeves' of vascular basement membrane are found. Instead, biophysical experiments reveal that the biomechanical properties of pancreatic islet cells, such as their actomyosin-mediated cortex tension and adhesive forces to endothelial cells, are significantly changed. These results suggest that a sorting event is driving the segregation of endothelial and epithelial cells and indicate that the epithelial biomechanical properties determine whether the blood vasculature invades or envelops a growing epithelial tissue.

Vascular development in the vertebrate pancreas.

The vertebrate pancreas is comprised of a highly branched tubular epithelium, which is intimately associated with an extensive and specialized vasculature. While we know a great deal about basic vascular anatomy of the adult pancreas, as well as islet capillaries, surprisingly little is known about the ontogeny of its blood vessels. Here, we analyze development of the pancreatic vasculature in the mouse embryo. We show that pancreatic epithelial branches intercalate with the fine capillary plexus of the surrounding pancreatic mesenchyme. Endothelial cells (ECs) within this mesenchyme are heterogeneous from the onset of organogenesis. Pancreatic arteries take shape before veins, in a manner analogous to early embryonic vessels. The main central artery forms during mid-gestation, as a result of vessel coalescence and remodeling of a vascular plexus. In addition, we show that vessels in the forming pancreas display a predictable architecture that is dependent on VEGF signaling. Over-expression of VEGF disrupts vascular patterning and arteriovenous differentiation within the developing pancreas. This study constitutes a first-time in-depth cellular and molecular characterization of pancreatic blood vessels, as they coordinately grow along with the pancreatic epithelium.

Quantitative Histomorphometry of the Healthy Peritoneum.

The peritoneum plays an essential role in preventing abdominal frictions and adhesions and can be utilized as a dialysis membrane. Its physiological ultrastructure, however, has not yet been studied systematically. 106 standardized peritoneal and 69 omental specimens were obtained from 107 patients (0.1-60 years) undergoing surgery for disease not affecting the peritoneum for automated quantitative histomorphometry and immunohistochemistry. The mesothelial cell layer morphology and protein expression pattern is similar across all age groups. Infants below one year have a thinner submesothelium; inflammation, profibrotic activity and mesothelial cell translocation is largely absent in all age groups. Peritoneal blood capillaries, lymphatics and nerve fibers locate in three distinct submesothelial layers. Blood vessel density and endothelial surface area follow a U-shaped curve with highest values in infants below one year and lowest values in children aged 7-12 years. Lymphatic vessel density is much lower, and again highest in infants. Omental blood capillary density correlates with parietal peritoneal findings, whereas only few lymphatic vessels are present. The healthy peritoneum exhibits major thus far unknown particularities, pertaining to functionally relevant structures, and subject to substantial changes with age. The reference ranges established here provide a framework for future histomorphometric analyses and peritoneal transport modeling approaches.

[Vascular Lesions of Vocal Folds - Part 2: Perpendicular Vascular Lesions]. / Gefäßveränderungen der Stimmlippen - Teil 2: Perpendikuläre Gefäßveränderungen.

The present work aims at a systematic pathogenetic description of perpendicular vascular changes in the vocal folds. Unlike longitudinal vascular changes, like ectasia and meander, perpendicular vascular changes can be observed in bening lesions. They predominantly occur as typical vascular loops in exophytic lesions, especially in recurrent respiratory papillomatosis (RRP), pre-cancerous and cancerous diseases of the larynx and vocal folds. Neoangiogenesis is caused by an epithelial growth stimulus in the early phase of cancerous genesis. In RRP the VVC impress by a single, long vessel loop with a narrow angle turning point in the each single papilla of the papilloma. In pre- and cancerous lesions the vascular loop is located directly underneath the epithelium. During progressive tumor growth, vascular loops develop an increasingly irregular, convoluted, spirally shape. The arrangement of the vascular loops is primarily still symmetrical. In the preliminary stage of tumor development occurs by neoangiogenesis to a microvascular compression. In advanced vocal fold carcinoma the regular vascular vocal fold structure is destroyed. The various stages of tumor growth are also characterized by typical primary epithelial and secondary connective tissue changes. The characteristic triad of vascular, epithelial and connective tissue changes therefore plays an important role in differential diagnosis.

Scar-free cutaneous wound healing in the leopard gecko, Eublepharis macularius.

Cutaneous wounds heal with two possible outcomes: scarification or near-perfect integumentary restoration. Whereas scar formation has been intensively investigated, less is known about the tissue-level events characterising wounds that spontaneously heal scar-free, particularly in non-foetal amniotes. Here, a spatiotemporal investigation of scar-free cutaneous wound healing following full-thickness excisional biopsies to the tail and body of leopard geckos (Eublepharis macularius) is provided. All injuries healed without scarring. Cutaneous repair involves the development of a cell-rich aggregate within the wound bed, similar to scarring wounds. Unlike scar formation, scar-free healing involves a more rapid closure of the wound epithelium, and a delay in blood vessel development and collagen deposition within the wound bed. It was found that, while granulation tissue of scarring wounds is hypervascular, scar-free wound healing conspicuously does not involve a period of exuberant blood vessel formation. In addition, during scar-free wound healing the newly formed blood vessels are typically perivascular cell-supported. Immunohistochemistry revealed widespread expression of both the pro-angiogenic factor vascular endothelial growth factor A and the anti-angiogenic factor thrombospondin-1 within the healing wound. It was found that scar-free wound healing is an intrinsic property of leopard gecko integument, and involves a modulation of the cutaneous scar repair program. This proportional revascularisation is an important factor in scar-free wound healing.

Impairment of vascularization of the surface covering epithelium induces ischemia and promotes malignization: a new hypothesis of a possible mechanism of cancer pathogenesis.

PURPOSE: To study the peculiarities of vascularization at the stromal-epithelial interface in different types of epithelia and their alterations in precancerous lesions. MATERIALS AND METHODS: Peritumoral tissues of 310 patients, tissues of 180 healthy persons and of 50 human embryos and fetuses were used. Traditional histological as well as immunohistochemical methods have been used. RESULTS: The study reveals that the occurrence of blood capillaries in surface squamous epithelium is an ordinary event, both in healthy persons and in peritumoral regions of the patients with squamous cell carcinoma. Glandular epithelial coverings, as well as transitional epithelium, do not contain blood vessels. In squamous epithelium, only basal cells are in contact with the membrane and underlying stroma, the cells of the upper layer receiving nutrients through diffusion. Thus, the cells of squamous epithelium are more vulnerable to blood deficiency, since for instance in the pseudo-multilayered respiratory epithelium each cell is attached directly to the basal membrane and has more ample access to the blood supply. Metaplastic squamous epithelium has a markedly reduced vascularization and seems to be more sensitive to carcinogenic stimuli. High-grade dysplastic squamous epithelium and carcinoma in situ do not contain blood vessels. CONCLUSION: The process of redistribution of vascular network occurring at the interface of epithelial-stromal frontier plays an important role in maintaining the adequate metabolism of cells including those of epithelial covering. Impairment of this mechanism most probably promotes precancerous alterations.

Microvasculature and healing potential of the inner versus outer preputial skin: preliminary immunohistochemical observations.

PURPOSE: To assess healing potential of the inner and the outer layers of the prepuce and to determine which layer is better for hypospadias neourethral reconstruction. MATERIALS AND METHODS: The study has been carried out to assess the microvessels density and epidermal growth factor receptor (EGFR) concentration in the inner and the outer preputial layers. Specimens from the outer and the inner prepuce were harvested during hypospadias repair in 26 children. Control specimens were collected during elective circumcision of 10 normal and age-matched children. Sections were prepared, and immunohistochemical staining was done using monoclonal antibodies of CD34 (vascular marker) and of the EGFR. CD34-positive microvessels were assessed under the outer and the inner layers of the prepuce and were counted in five high-power fields under each layer. Expression of EGFR in both layers was assessed using H-score system. RESULTS: The density of microvessels and EGFR expression are significantly higher in control group either for inner or for outer preputial layers (p < 0.05). Microvessels density in the inner prepuce in hypospadias group is slightly higher than that of the outer prepuce (p < 0.05). However, the wider lumen and well-developed wall of the microvessels in the outer layer may compensate for decreased number in comparison with the inner layer. Expression of EGFR was reduced in both inner and outer layers of the hypospadias prepuce with no significant difference (p > 0.05). CONCLUSION: In hypospadias patients, the healing potential of both inner and outer prepuce is nearly similar. However, it is markedly reduced than that of normal prepuce. It seems that both layers can be used for hypospadias repair without obvious preference to either of them. The usual tradition to use inner prepuce in hypospadias repair has no scientific evidence.

Comparative evaluation of the marginal gingival epithelium in smokers and nonsmokers: a histomorphometric and immunohistochemical study.

Smoking is one of the strongest predictors of attachment and bone loss. Smokers demonstrate reduced inflammatory clinical signs, which could be due to local vasoconstriction and increased gingival epithelial thickness. The byproducts originating from tobacco oxidation modify the clinical characteristics and progression of periodontal disease. The aim of this study was to investigate the relationship between the thickness of marginal gingival oral epithelium, sulcular bleeding, and vascular caliber and density of the microvessels in smokers and nonsmokers with and without periodontitis and to better understand the role of smoking in relation to periodontal disease. One hundred twenty individuals were enrolled in this study and divided into four groups comprising 30 participants each. The clinical measurements carried out included probing depth, clinical attachment loss, and bleeding index, along with gingival biopsy specimens, which were subjected to immunohistochemical and histomorphometric analysis. Correlation of the clinical and histologic features revealed that smokers presented with fewer inflammatory signs, had fewer vascular elements in the subepithelial connective tissue layer, and showed a resultant increase in epithelial thickness irrespective of the presence of periodontitis. There was a mean increase of epithelial thickness of 181.3 µm (suprapapillary epithelial thickness [SET]) to 380.2 µm (maximal epithelial thickness [MET]) in smokers with periodontitis as compared to 157.4 µm (SET) to 325.3 µm (MET) in nonsmokers with periodontitis. The mean microvascular density in smokers with periodontitis was 325.4 per mm, which was found to be statistically significantly less than that of nonsmokers with periodontitis, who had a mean value of 412.13 per mm. The vessel caliber also was reduced in smokers, with a mean value ranging from 4.7 to 6.1 µm compared with a mean of 6.2 to 9.2 µm in nonsmokers, irrespective of the presence of periodontitis. Statistically significant differences were found in vascular density and thickness of gingival epithelium between smokers and nonsmokers with and without periodontitis. These differences may impact the progression of periodontal disease.

Cellular specificity of the blood-CSF barrier for albumin transfer across the choroid plexus epithelium.

To maintain the precise internal milieu of the mammalian central nervous system, well-controlled transfer of molecules from periphery into brain is required. Recently the soluble and cell-surface albumin-binding glycoprotein SPARC (secreted protein acidic and rich in cysteine) has been implicated in albumin transport into developing brain, however the exact mechanism remains unknown. We postulate that SPARC is a docking site for albumin, mediating its uptake and transfer by choroid plexus epithelial cells from blood into cerebrospinal fluid (CSF). We used in vivo physiological measurements of transfer of endogenous (mouse) and exogenous (human) albumins, in situ Proximity Ligation Assay (in situ PLA), and qRT-PCR experiments to examine the cellular mechanism mediating protein transfer across the blood-CSF interface. We report that at all developmental stages mouse albumin and SPARC gave positive signals with in situ PLAs in plasma, CSF and within individual plexus cells suggesting a possible molecular interaction. In contrast, in situ PLA experiments in brain sections from mice injected with human albumin showed positive signals for human albumin in the vascular compartment that were only rarely identifiable within choroid plexus cells and only at older ages. Concentrations of both endogenous mouse albumin and exogenous (intraperitoneally injected) human albumin were estimated in plasma and CSF and expressed as CSF/plasma concentration ratios. Human albumin was not transferred through the mouse blood-CSF barrier to the same extent as endogenous mouse albumin, confirming results from in situ PLA. During postnatal development Sparc gene expression was higher in early postnatal ages than in the adult and changed in response to altered levels of albumin in blood plasma in a differential and developmentally regulated manner. Here we propose a possible cellular route and mechanism by which albumin is transferred from blood into CSF across a sub-population of specialised choroid plexus epithelial cells.

Narrow-band imaging system with magnifying endoscopy for early oral cancer.

It is often difficult to detect early oral cancer due to the specificity of the oral mucosa structure. The aim of this study was to investigate the potential of narrow band imaging (NBI) as an effective and non-invasive diagnostic tool in early oral cancer and other oral diseases. A magnifying endoscopy system manufactured by Olympus Corporation was used. A total of 121 subjects were included in the study. Subepithelial capillary loops were identified and categorized according to the classification of Inoue, with healthy mucosa graded as Type I or II, and that showing evidence of cancer-induced morphological change as Type III or IV. Sensitivity and specificity for the identification of oral cancer were estimated at 92.3% and 88.2%, respectively. Examination under a microscope with H&E staining and immunostaining for CD34 revealed dilation and extension of the capillaries in epithelial dysplasia, in addition to thickening of the epithelial layer. The present results indicate that use of NBI in conjunction with conventional magnifying endoscopy has great potential as an effective and non-invasive diagnostic tool in the early detection of oral cancer.

Vascular biology of the biliary epithelium.

Cholangiocytes are involved in a variety of processes essential for liver pathophysiology. To meet their demanding metabolic and functional needs, bile ducts are nourished by their own arterial supply, the peribiliary plexus. This capillary network originates from the hepatic artery and is strictly arranged around the intrahepatic bile ducts. Biliary and vascular structures are linked by a close anatomic and functional association necessary for liver development, normal organ physiology, and liver repair. This strong association is finely regulated by a range of angiogenic signals, enabling the cross talk between cholangiocytes and the different vascular cell types. This review will briefly illustrate the "vascular" properties of cholangiocytes, their underlying molecular mechanisms and the relevant pathophysiological settings.

DNA damage in human pterygium: one-shot multiple targets.

PURPOSE: Little is known about DNA damage in human pterygium, and no data about DNA damage involvement as a potential angiogenic factor are available. We studied, with immunohistochemistry, the presence and localization of thymine dimers in the epithelial and stromal components of the human primary pterygium and its recurrences with a special emphasis on the vascular network and its interactions with the p53 tumor suppressor gene protein. METHODS: Thirty-five primary human pterygium, three recurrences, and three normal bulbar conjunctiva were included in the present study. Formalin-fixed, paraffin-embedded tissues were submitted for immunohistochemical analysis with antithymine dimers and p53 antibodies. Thymine dimer and p53 nuclear staining was assessed in the epithelial and stromal components of pterygial tissues and normal counterparts. RESULTS: Thymine dimers were present in the epithelial and stromal components of human pterygium and its recurrences. The thymine dimers were detected in the epithelial component of the human pterygium with a higher density and intensity in the basal layer of the epithelium. Small blood vessels' endothelial cells showed positive reaction for antithymine dimer antibodies together with isolated positive expression found in the nuclei of perivascular cells. For the recurrent pterygium, dimer expression was found only in the subepithelial fibrovascular layer components and in scattered cells from the basal layer of the epithelium. P53 expression was positive in 38.5% of the cases in the epithelial compartment, and in two cases, scattered p53 positive endothelial, fibroblast-like, and perivascular cells were detected in the fibrovascular compartment. CONCLUSIONS: Thymine dimers in human pterygium and its recurrences suggest that DNA damage is involved not only in pterygium epithelial and fibrous proliferation but also in angiogenesis and lymphangiogenesis from this ocular lesion in a still incomplete elucidated pathogenic mechanism.

Implications of morphologic patterns of intraepithelial microvasculature observed by narrow-band imaging system in cases of oral squamous cell carcinoma.

PURPOSE: To investigate the intraepithelial microvascular morphology of oral squamous cell carcinoma (OSCC) by using narrow-band imaging (NBI) and analyze whether the intraepithelial papillary capillary loop (IPCL) patterns correlate with infiltration depth and disease severity in OSCC. METHODS: The clinicopathologic data, morphology of vascular architecture as observed by NBI, and histopathology of patients with OSCC were retrospectively reviewed and analyzed. RESULTS: A total of 80 patients, including 73 males and 7 females with an average age of 54.18±12.23 years, were enrolled. Three patterns of intraepithelial microvasculature were revealed by NBI and differences in these three patterns were significant with regard to pathologic T-classification (p<0.0001), N-classification (p=0.00022), TNM stage (p<0.0001), lymphovascular invasion (p<0.0001), perineural invasion (p=0.000299), depth of tumor infiltration (p<0.0001), and tumor differentiation (p<0.0001). A cut-off point of tumor infiltration of 10.012 mm was best predicted for the destructive pattern of IPCL (sensitivity=100%, specificity=90.0%). CONCLUSIONS: Three different patterns of IPCL, showing step-wise increased severity according to pathologic parameters, were observed by NBI in cases of OSCC. The pattern indicating IPCL destruction with angiogenesis was associated with more advanced disease stage.

[The value of esophageal intrapapillary capillary loop visualized by magnifying narrow-band imaging endoscopy in diagnosing esophageal mucosal pathology].

OBJECTIVE: To investigate the diagnostic potential of magnifying narrow-band imaging endoscopy (NBI-ME) for different intrapapillary capillary loop (IPCL) for the diagnosis of esophageal lesion. METHODS: Patients with abnormal esophageal mucosa found by white light gastroscopy in digestive endoscopy center, Chinese PLA General Hospital during the period of November 2009 to November 2010 were enrolled in this study. IPCL was observed and divided into different types by NBI-ME. Histopathology of biopsy or endoscopic submucosal dissection (ESD) specimens was evaluated and used as the gold standard to evaluate the diagnostic value of NBI-ME for IPCL. RESULTS: A total of 146 lesions from 145 subjects with esophageal mucosa abnormal were collected. Among them, 88 were pathology-proven inflammation, 5 were pathology-proven esophageal cancers, 20 were pathology-proven low intraepithelial neoplasia (LIN) and 33 were pathology-proven high intraepithelial neoplasia (HIN) detected with NBI-ME. By a per-lesion analysis, the accuracy of inflammation and cancer were 100% (88/88) and 7/7. For the sensitivity, specificity, accuracy, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio of LIN and HIN were 7/10, 69.8% (30/43), 69.8% (37/53), 35.0% (7/20), 90.9% (30/33), 12.5% (70/559), 2.3% (30/1290) and 87.1% (27/31), 72.7% (16/22), 81.1% (43/53), 81.8% (27/33), 80.0% (16/20), 634.1% (837/132) and 35.2% (124/352), respectively. CONCLUSIONS: NBI-ME can classify the different esophageal IPCL. Higher diagnostic accuracy of IPCL indicates the feasibility of NBI-ME for the efficacious diagnosis of esophageal inflammation and cancer. There is the higher diagnostic accuracy of HIN than LIN.

Vascular instruction of pancreas development.

Blood vessels course through organs, providing them with essential nutrient and gaseous exchange. However, the vasculature has also been shown to provide non-nutritional signals that play key roles in the control of organ growth, morphogenesis and homeostasis. Here, we examine a decade of work on the contribution of vascular paracrine signals to developing tissues, with a focus on pancreatic ß-cells. During the early stages of embryonic development, blood vessels are required for pancreas specification. Later, the vasculature constrains pancreas branching, differentiation and growth. During adult life, capillaries provide a vascular niche for the maintenance of ß-cell function and survival. We explore the possibility that the vasculature constitutes a dynamic and regionalized signaling system that carries out multiple and changing functions as it coordinately grows with the pancreatic epithelial tree.