Confocal microscopy patterns in nonmelanoma skin cancer and clinical applications

Reflectance confocal microscopy is currently the most promising noninvasive diagnostic tool for studying cutaneous structures between the stratum corneum and the superficial reticular dermis. This tool gives real-time images parallel to the skin surface; the microscopic resolution is similar to that of conventional histology. Numerous studies have identified the main confocal features of various inflammatory skin diseases and tumors, demonstrating the good correlation of these features with certain dermatoscopic patterns and histologic findings. Confocal patterns and diagnostic algorithms have been shown to have high sensitivity and specificity in melanoma and nonmelanoma skin cancer. Possible present and future applications of this noninvasive technology are wide ranging and reach beyond its use in noninvasive diagnosis. This tool can also be used, for example, to evaluate dynamic skin processes that occur after UV exposure or to assess tumor response to noninvasive treatments such as photodynamic therapy. We explain the characteristic confocal features found in the main nonmelanoma skin tumors and discuss possible applications for this novel diagnostic technique in routine dermatology practice.

Involvement of oxytocin in the nucleus tractus solitarii on central cardiovascular control: interactions with glutamate

Oxytocin (OT) is a peptide involved in several physiological functions in the central nervous system including central cardiovascular regulation. To clarify the role of endogenous OT in cardiovascular control, one group of anesthetized rats received unilateral microinjections of the OT receptor antagonist [d(CH(2))(5),Tyr(Me)(2),Orn(8)]-vasotocin (OTA) in the nucleus tractus solitarii (NTS) and a second group was injected with specific OT antiserum (Anti-OT). Moreover, the modulation of the cardiovascular effect of L-glutamate (GLU) by OT was also evaluated by cardiovascular analysis using effective and threshold doses of GLU. Mean arterial pressure (MAP) and heart rate (HR) were measured from a femoral catheter. OTA significantly (p<0.01) decreased the vasopressor and tachycardiac long-lasting response elicited by an effective dose of OT. Microinjections of Anti-OT antibody did not modify the values of MAP and HR compared with the control group. With regard to the OT/GLU coinjections, a subthreshold dose of OT significantly (p<0.001) counteracted the vasodepressor and bradycardiac responses induced by GLU. The coinjection of subthreshold doses of OT and GLU did not produce a change in MAP or in HR. These findings seem to exclude an endogenous tonic action of OT on central regulation of MAP and HR, although they confirm the significant role of OT on central cardiovascular control within the NTS. In fact, the modulation of GLU responses by OT supports the importance of OT on the central cardiovascular adjustments likely acting on the baroreceptor reflex sensitivity.

Dietary Lutein/Zeaxanthin Partially Reduces Photoaging and Photocarcinogenesis in Chronically UVB-Irradiated Skh-1 Hairless Mice

Lutein and zeaxanthin are xanthophyll carotenoids with potent antioxidant properties protecting the skin from acute photodamage. This study extended the investigation to chronic photodamage and photocarcinogenesis. Mice received either a lutein/zeaxanthin-supplemented diet or a standard nonsupplemented diet. Dorsal skin of female Skh-1 hairless mice was exposed to UVB radiation with a cumulative dose of 16,000 mJ/cm(2) for photoaging and 30,200 mJ/cm(2) for photocarcinogenesis. Clinical evaluations were performed weekly, and the animals were sacrificed 24 h after the last UVB exposure. For photoaging experiments, skin fold thickness, suprapapillary plate thickness, mast cell counts and dermal desmosine content were evaluated. For photocarcinogenesis, samples of tumors larger than 2 mm were analyzed for histological characterization, hyperproliferation index, tumor multiplicity, total tumor volume and tumor-free survival time. Results of the photoaging experiment revealed that skin fold thickness and number of infiltrating mast cells following UVB irradiation were significantly less in lutein/zeaxanthin-treated mice when compared to irradiated animals fed the standard diet. The results of the photocarcinogenesis experiment were increased tumor-free survival time, reduced tumor multiplicity and total tumor volume in lutein/zeaxanthin-treated mice in comparison with control irradiated animals fed the standard diet. These data demonstrate that dietary lutein/zeaxanthin supplementation protects the skin against UVB-induced photoaging and photocarcinogenesis.

Region specific galanin receptor/neuropeptide Y Y1 receptor interactions in the tel- and diencephalon of the rat. Relevance for food consumption

The aim of this work was to determine the interactions between NPY and GAL receptor (GALR) subtypes in the hypothalamus and the amygdala using quantitative receptor autoradiography to analyze the binding characteristics of NPY-Y1 and Y2 receptor subtypes in the presence and absence of GAL. Food intake in satiated animals was evaluated after intraventricular co-injections of GAL and NPY-Y1 or Y2 agonists. The expression of c-Fos IR in both regions was also investigated. GAL decreases NPY-Y1 agonist binding in the arcuate nucleus by about 15% (p<0.01), but increases NPY-Y1 agonist binding in amygdala (18%) (p<0.01). These effects were blocked with the GAL antagonist M35. Y2-agonist binding was not modified by GAL. GAL blocked the food intake induced by the Y1 agonist (p<0.01). Co-injections of Y1 agonist and GAL also reduced the c-Fos expression induced by the Y1 agonist in the arcuate nucleus and the dorsomedial hypothalamic nucleus but increased c-Fos expression in amygdala. These results indicate the existence of antagonistic interactions between GALR and NPY-Y1 receptors in the hypothalamus and their functional relevance for food intake. In contrast, a facilitatory interaction between GALR and Y1 receptors exists in the amygdala which may be of relevance for fear related behaviour.

[Expression of galanin in melanocytic tumors]

INTRODUCTION

Galanin is a neuropeptide with wide-ranging effects, especially within the endocrine and nervous systems. Galanin and its receptors are present in human skin. Galanin is expressed in different neural, endocrine and neuroendocrine tumors and, on the other hand, several neuropeptides, particularly alpha-MSH, seem to play a role in the pathogenesis of melanoma.

OBJECTIVE

To investigate the expression of galanin in cutaneous melanomas and melanocytic nevi and correlate it with alpha-MSH expression and several prognostic factors for melanoma.

MATERIAL AND METHODS

We performed an observational and retrospective study of the immunohistochemical expression of galanin and alpha-MSH in samples of cutaneous melanomas diagnosed in the last 5 years in the San Jorge Hospital, Huesca (Spain). Different types of melanocytic nevi were also analyzed.

RESULTS

A total of 130 pigmented lesions were studied: 38 primary cutaneous melanomas, 6 cutaneous melanoma metastases and 86 melanocytic nevi. Immunostaining with galanin and alpha-MSH was significantly higher in melanomas than in melanocytic nevi (p < 0.001), although spindle cell and blue nevi showed significant expression of alpha-MSH. More than 50 % of nodular melanomas and 90 % of superficial spreading melanomas were positive for galanin and alpha-MSH, and the latter also showed the highest percentage of positive cells for galanin (mean 35.09 +/- 28.16) as well as for alpha-MSH (mean 67.64% +/- 35.38). A positive correlation of 71 % was found for immunostaining of both neuropeptides in melanomas. No significant correlation was observed between galanin expression and age, gender, location of the lesions, Breslow index, Clark level and mitotic index.

CONCLUSION

Our study shows the expression of galanin in cutaneous melanoma and its significant correlation with alpha-MSH immunostaining.

Receptor–receptor interactions in central cardiovascular regulation. Focus on neuropeptide/α2-adrenoreceptor interactions in the nucleus tractus solitarius

The nucleus tractus solitarii (NTS) is a key nucleus in central cardiovascular control. In this mechanism it is well known the role of the alpha(2)-adrenoreceptors for the modulation of the autonomic pathways. Moreover a number of neuropeptides described in the NTS, including Neuropeptide Y (NPY), Galanin (GAL) and Angiotensin II (Ang II), have different roles in regulating the cardiovascular function within this nucleus. We show in this review several data which help to understand how these neuropeptides (NPY, GAL and Ang II) could modulate the cardiovascular responses mediated through alpha(2)-adrenoreceptors in the NTS. Also we show for the first time the interactions between neuropeptides in the brain, specifically the interactions between NPY, GAL, and Ang II, and its functional relevance for central cardiovascular regulation. These data strength the role of neuropeptides on central autonomic control and provide some evidences to understand the neurochemical mechanisms involved in the cardiovascular responses from the NTS.

Effects of a non-selective beta-blocker on adult rat anterograde axonal transport and retinal ganglion layer after increased intraocular pressure

The aim of this study was to examine the effects of timolol in an experimental model of elevated intraocular pressure (IOP). Three episcleral veins of rats with normal IOP were cauterized. Three months later we examined the effects on anterograde axonal transport from the retinal ganglion cells (RGCs) to the superior colliculus (SC) as well as on the number of neurons in the retinal ganglion layer (RGL). These parameters were also studied in a group of rats submitted to treatment with timolol after confirming that their IOP was still raised after two weeks. After the surgical procedure, the mean IOP of the experimental eyes increased to 33.5+/-1.06 mmHg (1.25 fold compared to the control group) and three months later the IOP remained significantly elevated; however, after a long period of treatment with timolol the IOP was 14.05+/-0.81 mmHg, similar to that of the control group. In the group with normal IOP, labelling with horseradish rabbit peroxidase (HRP) at 120 minutes and 24 hours postinjection showed continuous staining from the retina to the SC. In the experimental group the optic nerve head (ONH) was completely negative, although in the group treated with timolol there was partial block of axonal transport in the ONH, in which the staining was slightly more intense. The number of neurons in the RGL, counted by immunohistochemical labelling with Neu-N, showed that in eyes with normal and elevated IOP there were 423+/-11 neurons/mm(2) and 283+/-10 neurons/mm(2), respectively. After treatment with timolol the number of neurons (331+/-10 cells/mm(2) increased compared with elevated IOP eyes, although the number did not reach that of the control group. These results indicate that treatment with timolol, started two weeks after the surgical procedure, was partially neuroprotective because the loss of neurons in the RGL was lower than in untreated animals, though not sufficient to re-establish normal axonal transport.

Role of galanin and galanin(1-15) on central cardiovascular control

Galanin and the N-terminal fragment Galanin(1-15) are involved in central cardiovascular regulation. The present paper reviews the recent cardiovascular results obtained by intracisternal injections of Galanin and Galanin(1-15) showing that: (A) the Galanin antagonist M40 blocks the central cardiovascular responses induced by Galanin(1-15) but not those elicited by Galanin; (B) both Galanin and Galanin(1-15) induce the expression of c-Fos in cardiovascular nuclei of the medulla oblongata with different temporal and spatial profiles; (C) the cardiovascular action of Galanin(1-15), but not Galanin, is mediated by peripheral beta-receptor stimulation; (D) and it is demonstrated an antagonistic Galanin/alpha2-adrenoceptors interaction as well as a differential modulation of central cardiovascular responses of Angiotensin II by Galanin or Galanin(1-15). All these data strengthen the involvement of both Galanin molecules as neuromodulators on central cardiovascular regulation.

MOC-31/Ep-CAM immunoreactivity in Merkel cells and Merkel cell carcinomas

AIMS

To evaluate the monoclonal antibody MOC-31 in Merkel cell carcinomas and normal Merkel cells. Merkel cell carcinoma is a rare and aggressive tumour that occurs mainly in elderly individuals. The histological diagnosis of Merkel cell carcinoma can be difficult because it looks similar to other small blue cell tumours, particularly skin metastases of small-cell lung carcinomas. This antibody recognizes the epithelial cell adhesion molecule (Ep-CAM), that has been assigned to the small cell lung cancer cluster 2 of antibodies. To the best of our knowledge, immunostaining for MOC-31/Ep-CAM has not been previously described in Merkel cells or Merkel cell carcinomas.

METHODS AND RESULTS

Thirty-one cases of Merkel cell carcinoma and three samples of normal human fingertip were selected to analyse the expression of MOC-31/Ep-CAM by immunohistochemistry. A high number of Merkel cell carcinomas (21/31, 67.7%) showed intense and readily interpretable positivity. Immunostaining was diffuse or focal and always localized to the plasma membrane. Normal Merkel cells of human fingertip also showed plasma membrane immunoreactivity for MOC-31/Ep-CAM.

CONCLUSION

The demonstration of positivity for MOC-31/Ep-CAM in Merkel cell carcinomas precludes the use of this immunohistochemical marker to distinguish between tumours and skin metastases of small-cell lung carcinoma.

Pattern of distribution and prognostic value of angiogenesis in pancreatic duct carcinoma: a semiquantitative immunohistochemical study of 45 patients

In specimens obtained from resected pancreata, the intratumoral microvessel density (IMD), the proliferation rate of the neoplastic parenchymal cells, and their p53 protein expression were assessed. The sources of errors were great in the measurements of the IMD. This statement can be illustrated by the finding that when the IMD was calculated by manual counting in five areas of intense neovascularization (hot spot regions), using x200 and x400 magnifications, the numbers of microvessels per square millimeter were 65+/-23 and 106+/-8, respectively, which reflects a significant difference. Two patterns of microvessel distribution could be identified: one with hot spots only in the stroma (n = 19) and one in which the hot spots were located in areas of neoplastic parenchyma (including its stroma) (n = 26). The IMD was significantly greater in the latter group. There was no general correlation of neoplastic disease with the IMD. However, when a scoring system was used to assess the angiogenesis, hot spots in areas of neoplastic parenchyma were associated with a greater proliferation rate of the tumor cells, and with a short length of survival of the patients from their neoplastic disease.

A quantitative investigation of microvascular changes in the thyroid gland after infrared (IR) laser radiation

We present an ultrastructural study of thyroid capillaries in which 50-day-old rats Wistar rats, were irradiated with an infrared (IR) laser, (total dose, 46.80 J/cm2), the tissue quantified 1 day after ending treatment and a quantitative capillary analysis carried out by light and electron microscopy. Light microscopy was used to calculate capillary volume density revealing a significant increase in the irradiated rats. The quantitative measurement of parameters by electron microscopy required a two stage analysis: Level I, Electron Microscopy (Magnification x5,000); and Level II, Electron Microscopy (Magnification x26,000). At Level I, the following parameters were measured in each capillary: capillary area, capillary diameter, luminal area, luminal diameter, endothelial area, nuclear area and mean endothelial thickness. At Level II, pinocytotic vesicle diameter and their numerical density in endothelial cells were evaluated. Electron microscopic analysis revealed an increased luminal area in the capillaries of the irradiated rats. They also presented a decrease in endothelial cell thickness and vesicular diameter and an increase in vesicle numerical density. This latter increase is indicative of presumptive changes in capillary permeability, but the possible functional significance of these morphological changes in the endothelial cells requires further investigation.

Graphite-Teflon composite bienzyme electrodes for the determination of L-lactate: application to food samples

A bienzyme amperometric graphite-Teflon composite biosensor, in which lactate oxidase (LOD) and peroxidase, together with the mediator ferrocene, are incorporated into the electrode matrix, was developed for the determination of L-lactate in food samples such as wine and yogurt by using both batch- and flow-injection modes. This bienzyme electrode was fabricated by simple physical inclusion of the enzymes and the mediator in the bulk of the graphite-Teflon matrix. A Teflon content of 70%, an applied potential of 0.00 V, and a pH of 7.4 were employed as working conditions. The composite bioelectrode exhibited long-term operation because of the renewability of its surface by polishing. Reproducible amperometric responses were achieved with different electrodes fabricated from different composite matrices, and no significant loss of the enzyme activity occurred after 6 months of storage at 4 degrees C. Detection limits for L-lactate of 1.4 and 0.9 microM were obtained by batch amperometry in stirred solutions and flow-injection with amperometric detection, respectively. An interferences study with different substances which may be present in wine and yogurt together with L-lactic acid demonstrated very good selectivity for the determination of this analyte. The bienzyme composite electrode was applied to the determination of L-lactic acid in red wine and shaken yogurt, and the methods were validated by comparing these results with those obtained by applying a recommended reference method.

Mechanism of contrast enhancement in breast lesions at MR imaging

PURPOSE

The aim of the study was to explain why breast lesions are enhanced by contrast medium at MR imaging and to elucidate the histopathological basis for the overlap in the enhancement patterns of benign and malignant breast lesions.

MATERIAL AND METHODS

Ten invasive breast carcinomas and 10 benign breast lesions were selected for the study. Of the 10 carcinomas, 5 showed a strong and early contrast enhancement, and 5 did not. Of the 10 benign lesions, 5 showed a strong and early contrast enhancement, and 5 showed no enhancement. The following morphometric variables were evaluated: proliferation cell index of neoplastic parenchymal cells, S-phase fraction, nuclear ploidy analysed by image DNA-cytometry, microvessel density, and the percentage proportion of the interstitial area.

RESULTS

Contrast enhancement was related to the proliferating activity of the hyperplastic or neoplastic parenchymal cells and was inversely correlated with the interstitial area in carcinomas as well as in benign tumours and non-neoplastic lesions of the breast.

CONCLUSION

Morphometric variables play an important role in the general mechanism of MR contrast enhancement in examinations of the breast and explain the histopathological basis for the overlap in the enhancement patterns of benign and malignant breast lesions.

Prognosticating tools in primary neuroendocrine (Merkel-cell) carcinomas of the skin: histopathological subdivision, DNA cytometry, cell proliferation analyses (Ki-67-immunoreactivity) and NCAM immunohistochemistry. A clinicopathological study in 25 patients

Histopathologically, 18 of our patients had classical Merkel-cell carcinomas (MCC); seven had neuroendocrine (NE) carcinomas with features different from MCC, here called "aberrant MCC". These patients showed a progressive neoplastic disease with a fatal outcome in four of them. The cytometric DNA distribution pattern of the tumor cell nuclei of all the aberrant MCCs was found to be of the aneuploid type. By contrast, the neoplastic disease of the majority of patients with classical MCC ran a milder course; a fatal outcome occurred in only one of them. Here, the DNA ploidy pattern was of the euploid (diploid or tetraploid) type in eight cases and of the aneuploid type in another eight. Our recently described "proliferation cell index" (PCI), based on nuclear immunoreactivity (IR) with the proliferation "marker" antigen Ki-67, was significantly lower in those five MCCs of the classical "DNA-diploid" type than in the seven "DNA-aneuploid" ones. These five patients presented a mild neoplastic disease; only one had a local recurrence and none had metastases. Otherwise, neither the PCI values nor the NCAM IR of the MCC cells were found to be of any prognostic significance.

Prognostic significance of Ki-67 antigen and p53 protein expression in pancreatic duct carcinoma: a study of the monoclonal antibodies MIB-1 and DO-7 in formalin-fixed paraffin-embedded tumour material

Formalin-fixed paraffin-embedded material from 57 patients in whom curative resection of pancreatic carcinoma had been attempted was analysed by an immunohistochemical procedure to estimate proliferation and p53 protein expression. Using the monoclonal antibody (MAb) MIB-1, which recognizes a Ki-67 epitope, the proliferating cell index (PCI, percentage of immunoreactive tumour nuclei) and proliferating cell area (PCA, percentage of immunoreactive tumour nuclear area) were calculated using an interactive image analysis system and were compared with semiquantitative scoring of stainability. MAb DO-7, which recognizes both wild- and mutant-type p53 protein, was used to assess p53 expression in the same material. MIB-1 stainings were of high quality in 53 tumours. The median PCI was 29.7% (range 0.5-82.1%) and the median PCA was 10.6% (range 0.0-36.5%). There was a close correlation between PCI and PCA (P < 0.0001). PCI and PCA values were in conformity with the semiquantitative scoring (P < 0.0001). The p53 immunohistochemical stainings were successful in 48 tumours and the protein was expressed in 22 (46%). High PCI values (> 45%, n = 14) correlated with shorter survival time (P < 0.01). PCA (P < 0.05) and the expression of p53 protein (P < 0.001) were independent prognostic variables.

A technique for automatic/interactive assessment of the proliferating fraction of neoplastic cells in solid tumors. A methodological study on the Ki-67 immunoreactive cells in human mammary carcinomas, including a comparison with the results of conventional S-phase fraction assessments by means of DNA cytometry

Based on a computerized microscopy technique, a method has been devised which allows the practising pathologist to easily and rapidly assess quantitatively the relative number of actively proliferating neoplastic parenchymal cells in a tumor nodule. Our method has been tested on a series of 20 conventionally formalin-fixed and paraffin-embedded female mammary adenocarcinomas, using immunoreactivity with the MIB-1 monoclonal antibody against the cell proliferation antigen Ki-67. The values of the proportion of the MIB-1 immunoreactive cell nuclei were compared with those obtained DNA-cytometrically for the fraction of cells in the S-phase; a good correlation was found, although the MIB-1 values were consistently somewhat higher. A prerequisite for a success of the method was, of course, to achieve standardization of the MIB-1 immunostaining technique. By making simple adjustments of it, it could actually be improved to such an extent that almost the same color calibration and thresholding setup could be used. The measuring technique could be either interactive or automatic. The total number of immunoreactive and non-immunoreactive nuclei, as well as the total nuclear area of both cell types were registered in a computerized device. The data were accumulated sequentially for each measure field. To investigate the reproducibility of the immunostaining, two slides of each case were stained on different occasions. Each slide was measured three times; systemically randomly in the x- and y-axis-directions as well as in the subjectively defined histopathologically "most proliferative" area of the tumor. The values obtained were in good agreement with each other and obviously gave some valuable and objective supplementary pieces of information to that of the conventional clinical and histopathologic assessment of the degree of aggressiveness of a malignant neoplasm.

Study of the DNA content of basal and suprabasal keratinocytes in psoriatic patients

We carried out a cytophotometric study of the DNA content of basal and suprabasal keratinocytes using involved and uninvolved histological sections of epidermis from psoriatic patients using the Feulgen technique. The reference 2C value of the DNA content was obtained from lymphocyte nuclei in a sub-epidermal infiltrate from normal skin. According to the DNA content profiles obtained for the keratinocytes of psoriatic patients, individuals were classified into three groups: Group 1, composed of individuals with a monomodal diploid profile and preferential keratinocytes with a 2C DNA content and, hence, a low proliferation activity; Group 2, consisting of patients with significantly increased 2C-4C and 4C populations; and Group 3, made up of individuals with high proportions of 4C and hyperdiploid (6C, 8C, and > 8C) keratinocytes. The results obtained in this work and the observed changes in the proliferative activity of the keratinocytes in the three groups of patients led us to suggest that the cytophotometric determination of the DNA content of basal and suprabasal keratinocytes may be useful as a prognostic criterion for the classification of psoriatic patients in terms of the extent of alteration of their proliferative epidermal activity.

Application of morphometric methods to the cytologic study of intradermal nevi

Twenty-one intradermal nevi were studied by morphometric methods in an attempt to morphologically characterize the two types of nevus cell--epithelioids, type A, and fusiforms, type C--and to quantify the differences between them. Morphometric parameters of the intradermal nevi were compared with similar parameters of melanocytes and melanoma cells so that the maturation rates of the nevi cells could be established and to see if the parameters might indicate the degree of malignancy. Superficial nevus cells were differentiated from deep cells by their larger size and larger nuclear area. Nuclear area appeared to have potential for differentiating benign from malignant tumors. Decrease in cellular area appeared to indicate maturation rather than atrophy. Melanoma cells were differentiated by their larger size. Cell nuclear perimeter appeared to have confirmatory value, while cell perimeter was inconclusive.

Continuous thin-layer chromatography of sugars of clinical interest in samples of urine impregnated on paper

A procedure for the analysis of sugars of clinical interest in samples of urine impregnated on Whatman 3MM paper is described. The sugars are eluted from the sample and spotted directly on to the application zone of concentration-zone silica gel plates. followed by continuous development. The optimal composition of the eluent and developing solvent and the optimal development distance were established, together with the development time and its influence of the RF values. The locating reaction is based on the reduction of vanadium (V) to vanadium (IV) in acidic medium.