49 research outputs found

    Micro‐ornamentation patterns in different areas of the epidermis in the gecko Tarentola mauritanica reflect variations in the accumulation of corneous material in Oberhautchen cells

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    Micro-ornamentations characterize the surface of scales in lepidosaurians and are summarized in four main patterns, i.e., spi- nulated, lamellated, lamellate-dentate, and honeycomb, although variations of these patterns are present in different species. Although geckos are known to possess a spinulated pattern derived from the Oberhautchen layer, also other pattern variations of the spinulated micro-ornamentation are present such as those indicated as dendritic ramification, corneous belts, and small bare patches. The present study mainly describes the variation of micro-ornamentations present in scales of different skin regions in the Mediterranean gecko Tarentula mauritanica using scannig and transmission electron microscopy. The study reports that the accumulation of corneous material in Oberhautchen cells is not homogenous in different areas of body scales and, when mature, this process gives rise to different sculpturing on the epidermal surface generating not only spinulae but also transitional zones leading to the other main patterns. It is hypothesized that spinulae formation derives from the verti- cal and lateral symmetric growth of tubercolate, non-overlapped scales of geckos. Sparse areas also result smooth or with serpentine-ridges likely revealing the beta-layer located underneath and merged with the Oberhautchen. The eco-functional role of this variable micro-ornamentation in the skin of lizards however remains largely speculative

    Cervical lymph node metastasis in high-grade transformation of head and neck adenoid cystic carcinoma: a collective international review

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    Adenoid cystic carcinoma (AdCC) is among the most common malignant tumors of the salivary glands. It is characterized by a prolonged clinical course, with frequent local recurrences, late onset of metastases and fatal outcome. High-grade transformation (HGT) is an uncommon phenomenon among salivary carcinomas and is associated with increased tumor aggressiveness. In AdCC with high-grade transformation (AdCC-HGT), the clinical course deviates from the natural history of AdCC. It tends to be accelerated, with a high propensity for lymph node metastasis. In order to shed light on this rare event and, in particular, on treatment implications, we undertook this review: searching for all published cases of AdCC-HGT. We conclude that it is mandatory to perform elective neck dissection in patients with AdCC-HGT, due to the high risk of lymph node metastases associated with transformation

    Bristles formation in adhesive pads and sensilli of the gecko Tarentola mauritanica derive from a massive accumulation of corneous material in Oberhautchen cells of the epidermis

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    Among lizards, geckos possess special digital scales modified as hairy-like lamellae that allow attachment to vertical substrates for the movement using adhesive nanoscale filaments called setae. The present study shows new ultrastructural details on setae formation in the gecko Tarentula mauritanica. Setae derive from the special differentiation of an epidermal layer termed Oberhauchen and can reach 30–60 μm in length. Oberhautchen cells in the adhesive pad lamellae becomes hypertrophic and rest upon 2 layers of non-corneous and pale cells instead of beta-cells like in the other scales. Only 1–2 beta-layers are formed underneath the pale layer. Setae derive from the accumulation of numerous roundish and heterogenous beta-packets with variable electron-density in Oberhautchen cells, possibly indicating a mixed protein composition. Immunofluorescence and immunogold labeling for CBPs show that beta-packets merge at the base of the growing setae forming long corneous bundles. Pale cells formed underneath the Oberhautchen layer contain small vesicles or tubules with a likely lipid content, sparse keratin filaments and ribosomes. In mature lamellae these cells merge with Oberhautchen and beta-cells forming a thin electron-paler layer located between the Oberhautchen and the thin beta-layer, a variation of the typical sequence of epidermal layers present in other scales. The formation of a softer pale layer and of a thin beta-layer likely determines a flexible corneous support for the adhesive setae. The specific molecular mechanism that stimulates the cellular changes observed during Oberhautch

    Prevalence of obstructive sleep apnea in a sample of bese women: effect of menopause

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    BACKGROUND: Obesity is a well known risk factor for obstructive sleep apnoea (OSA). Previous studies have investigated the prevalence of OSA among obese people, but a sample of women was rarely studied. OBJECTIVE: To describe the anthropometric and polysomnographic characteristics of a sample of obese women and investigate the effect of menopause on the prevalence of OSA. MATERIALS AND METHODS: Using a full-night polysomnography we studied a sample of 133 obese women with a body mass index (BMI) > or = 30 kg/m2. RESULTS: About 44% of our sample had a respiratory disturbance index (RDI) > or = 10. Neck circumference, BMI and age resulted the strongest predictors of RDI value. We also found that the prevalence of OSA was higher among post-menopausal women (67%) in comparison with pre-menopausal women (31%). Moreover, post-menopausal women had larger neck circumference and higher waist-to-hip circumference ratio (WHR). CONCLUSIONS: Among post-menopausal obese women the prevalence of OSA increases. We suggest that menopause could cause a different body fat distribution with an increase of fat in upper parts of the body and, consequently, with an increase of neck circumference

    Prevalence of obstructive sleep apnoea in a sample of obese women: effect of menopause

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    Obesity is a well known risk factor for obstructive sleep apnoea (OSA). Previous studies have investigated the prevalence of OSA among obese people, but a sample of women was rarely studied.Background: Obesity is a well known risk factor for obstructive sleep apnoea (OSA). Previous studies have investigated the prevalence of OSA among obese people, but a sample of women was rarely studied. Objective: To describe the anthropometric and polysomnographic characteristics of a sample of obese women and investigate the effect of menopause on the prevalence of OSA. Materials and methods: Using a full-night polysomnography we studied a sample of 133 obese women with a body mass index (BMI) ≥30 kg/m2. Results: About 44% of our sample had a respiratory disturbance index (RDI) ≥10. Neck circumference, BMI and age resulted the strongest predictors of RDI value. We also found that the prevalence of OSA was higher among post-menopausal women (67%) in comparison with pre-menopausal women (31%). Moreover, post-menopausal women had larger neck circumference and higher waist-to-hip circumference ratio (WHR). Conclusions: Among post-menopausal obese women the prevalence of OSA increases. We suggest that menopause could cause a different body fat distribution with an increase of fat in upper parts of the body and, consequently, with an increase of neck circumference. © 2004, Editrice Kurtis
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