265 research outputs found

    Anatomical variants of sphenoid sinuses pneumatisation: a CT scan study on a Northern Italian population

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    Sphenoid bone may be affected by different variants of pneumatisation, which have a relevant importance from a clinical and surgical point of view. The description of such variants in different populations may give useful information. However, few articles describe the variability of sphenoid pneumatised structures and none of them focuses on Northern Italian population. Variants of pneumatisation of sphenoid bone were described in a sample of 300 Northern Italian patients who underwent a CT scan. More than fifty-seven percent of patients showed a form of anatomical variant: the most common form was the pneumatised pterygoid processes (39.6%), followed by dorsum sellae (32.9%) and clinoid processes (20.3%), without statistically significant differences between males and females (p\ua0>\ua00.01). In 26.3% of patients, a combined pneumatisation of these three structures was observed, being the combination pterygoid processes-dorsum sellae the most frequent (11.3%). In 9.3%, all the three sphenoid structures were affected. This article is the first description of the prevalence of different variants of pneumatisation in a Northern Italian population: the occurrence of such forms has to be acknowledged for their possible clinical and surgical consequences

    Anatomical Characteristics Of Intrapetrous Carotid Artery : A 3d Segmentation Study On Head Ct-Scan

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    The intrapetrous portion of internal carotid artery (IPCA) is one of the most unexplored anatomical regions, and its three-dimensional reconstruction in living subjects is still missing. The present study aims at describing IPCA on 3D models extracted from head CT-scans. The intrapetrous carotid artery was manually segmented on head CT-scans of 100 healthy patients free from vascular and neurological pathologies (50 males and 50 females aged between 18 and 91 years). Angles of the posterior and anterior genu, diameter and length of the horizontal portion, and volume of the entire canal were calculated through VAM\uae software. Statistically significant differences according to sex and side were assessed through two-way ANOVA test (p<0.05). Correlation of each measurement with age was calculated as well. On average the angles of the posterior and anterior genu were 120.1\ub110.4\ub0 and 118.0\ub110.0\ub0 in males, 119.5\ub19.2\ub0 and 117.6\ub110.3\ub0 in females, respectively, without statistically significant differences according to sex or side (p>0.05). Average length and diameter of the horizontal part were respectively 25.5\ub12.9 mm and 5.8\ub10.8 mm in males, 24.0\ub12.3 mm and 5.3\ub10.8 mm in females. The volume of IPCA was 0.941\ub10.215 cm3 in males, and 0.752\ub10.159 cm3 in females. Length and diameter of horizontal portion, and volume of IPCA showed statistically significant differences according to sex (p<0.05). No correlation with age was found. This study first provided data concerning not only linear and angular measurements, but also volumes of IPCA, useful in planning surgical interventions of the cranial base

    Bleaching melanin in formalin-fixed and paraffin-embedded melanoma specimens using visible light : a pilot study

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    In fluorescence microscopy, light radiation can be used to bleach fluorescent molecules in formalin-fixed and paraffin-embedded (FFPE) samples, in order to increase the ratio between signal of interest and background autofluorescence. We tested if the same principle can be exploited in bright field microscopy to bleach pigmented melanoma FFPE sections together with cell morphology maintenance. After dewaxing and rehydration, serial FFPE sections of a feline diffuse iris melanoma, a canine dermal melanoma, a gray horse dermal melanoma and a swine cutaneous melanoma were irradiated with visible light for 1, 2, 3, 4 and 5 days, prior to Hematoxylin and Eosin staining. Complete bleaching was obtained after 1-day treatment in feline and swine melanomas, while 2 and 3 days were required in canine and equine neoplasms, respectively. In all treated samples, cell morphology was maintained. Photo-induced bleaching combined with immunohistochemistry was tested after a 3-day photo-treatment using five different markers. According to the literature, in all samples neoplastic cells stained positive for vimentin, S100 and PNL2, while negative for FVIII and pancytokeratin. In conclusion, visible light can be effectively exploited to bleach pigmented melanoma FFPE sections prior to perform routine histochemical and immunohistochemical stains

    Efeitos de corticosteróides em recém-nascidos de muito baixo peso, dependentes de ventilação mecânica

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    Corticosteroids have been used in bronchopulmonary dysplasia prevention because of their antiinflammatory effects. Among their effects is a decrease in the incidence of bronchopulmonary dysplasia. However, short- and long-term side effects have been detected in preterm newborns. PURPOSE: To analyze the effects of corticosteroids on bronchopulmonary dysplasia, length of stay, mortality, growth, as well as the adverse effects in very low birth weight newborns between 10 and 14 days of life and dependent on mechanical ventilation. METHODS: Cohort study. All newborns with a birth weight under 1500 g, mechanical ventilation-dependent between 10 and 14 days of life, during the period January 2000 and June 2001 were included (n = 38). They were divided into 2 groups: Group I with corticosteroids (n = 16) and Group II without corticosteroids (n = 22). Dexamethasone administration: from the 10th day of life, d1 - d3, 0.3 mg/kg/d; d4 - d6, 0.2 mg/kg/d; d7 - d9, 0.1 mg/kg/d. Respiratory evolution, bronchopulmonary dysplasia (oxygen dependence at 28 days of life), growth pattern and the presence of adverse effects were analyzed. RESULTS: The incidence of bronchopulmonary dysplasia was 6.5% (Group I) and 30% (Group II), P = .07. A decrease in growth was detected in Group I compared with Group II (change in weight: Group I - 47 g/week, Group II - 85.5 g/week, P = .06; change in head circumference: Group I - 0.75 cm/week, Group II - 1 cm/week, P = .05). CONCLUSION: Use of corticosteroids in very low birth weight infants dependent on mechanical ventilation during the first 10 to 14 days of life did not affect the respiratory evolution and occurrence of bronchopulmonary dysplasia, but the velocity of growth was reduced.Devido às suas ações anti-inflamatórias, os corticosteróides têm sido utilizados para prevenção de displasia broncopulmonar, sendo descrita, uma redução da incidência desta patologia. No entanto, efeitos adversos a curto e a longo prazo têm sido detectados, em recém-nascidos pré-termo. OBJETIVO: Analisar os efeitos sobre a incidência de displasia broncopulmonar, duração de ventilação mecânica e de internação, mortalidade, crescimento, além dos efeitos adversos dos corticosteróides, administrados entre 10-14 dias de vida, em recém-nascidos de muito baixo peso, dependentes de ventilação mecânica. MÉTODOS: Realizou-se estudo de coorte, incluindo-se todos os recém-nascidos com peso de nascimento < 1500 gramas dependentes de ventilação mecânica, entre 10-14 dias de vida. Foram divididos em: Grupo I - receberam dexametasona (16) e Grupo II - não receberam dexametasona (22). Administrou-se dexametasona, a partir do 10º dia de vida, dias 1 a 3 - 0,3 mg/kg/d, dias 4 a 6 - 0,2 mg/kg/d, dias 7 a 9 - 0,1 mg/kg/d. Analisou-se o desenvolvimento de displasia broncopulmonar (dependência de oxigênio aos 28 dias de vida), efeitos sobre a evolução respiratória e sobre o padrão de crescimento, além da ocorrência de efeitos adversos. RESULTADOS: A incidência de displasia broncopulmonar não diferiu entre os grupos (GI - 62,5%; GII - 22,7%;p = 0,07). Detectou-se desaceleração do crescimento no GI em relação ao GII(D P = 47g/semana, GI e 85,5g/semana, GII; p = 0,06; D PC - 0,75 cm/semana GI e 1cm/semana, no GII; p = 0,05). CONCLUSÃO: O uso de corticosteróides, em recém-nascidos pré-termo, entre 10 - 14 dias de vida não reduziu incidência de displasia broncopulmonar e causou uma desaceleração do crescimento

    Symmetry of zygomatic bone through 3D segmentation on CT-scan and &quot;mirroring&quot; procedure: a novel approach for reconstructive maxillofacial surgery

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    Zygomatic bones are among those most frequently fractured facial bones [1]: symmetry is the golden standard for a correct restoration of zygomatic shape, but literature is divided about the best method for its quantification. Also, no information about the actual 3D symmetry of this bone in healthy subjects is available. This study aims at exposing an innovative approach for the assessment of zygomatic symmetry through 3D surface analysis. One hundred patients (50 males and 50 females) were selected from the CT-scans database from a Northern Italy hospital. Zygomatic bones from each patient were segmented, the left bone was automatically mirrored according to the sagittal plane and registered on the right one according to the least point-to-point distance between the two surfaces. Mean and RMS (root mean square) distance between the two models was then calculated. Possible statistically significant differences according to sex and age groups were assessed respectively through two-way ANOVA test (p0.05). This study first provides an overall assessment of symmetry of zygomatic bone, based on surface analysis: results may provide a useful indication for the reconstruction of zygomatic bones in maxillofacial surgery

    What is life? A perspective of the mathematical kinetic theory of active particles

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    The modeling of living systems composed of many interacting entities is treated in this paper with the aim of describing their collective behaviors. The mathematical approach is developed within the general framework of the kinetic theory of active particles. The presentation is in three parts. First, we derive the mathematical tools, subsequently, we show how the method can be applied to a number of case studies related to well defined living systems, and finally, we look ahead to research perspectives

    The Vitamin A Derivative All-Trans Retinoic Acid Repairs Amyloid-β-Induced Double-Strand Breaks in Neural Cells and in the Murine Neocortex.

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    The amyloid-β peptide or Aβ is the key player in the amyloid-cascade hypothesis of Alzheimer's disease. Aβ appears to trigger cell death but also production of double-strand breaks (DSBs) in aging and Alzheimer's disease. All-trans retinoic acid (RA), a derivative of vitamin A, was already known for its neuroprotective effects against the amyloid cascade. It diminishes, for instance, the production of Aβ peptides and their oligomerisation. In the present work we investigated the possible implication of RA receptor (RAR) in repair of Aβ-induced DSBs. We demonstrated that RA, as well as RAR agonist Am80, but not AGN 193109 antagonist, repair Aβ-induced DSBs in SH-SY5Y cells and an astrocytic cell line as well as in the murine cortical tissue of young and aged mice. The nonhomologous end joining pathway and the Ataxia Telangiectasia Mutated kinase were shown to be involved in RA-mediated DSBs repair in the SH-SY5Y cells. Our data suggest that RA, besides increasing cell viability in the cortex of young and even of aged mice, might also result in targeted DNA repair of genes important for cell or synaptic maintenance. This phenomenon would remain functional up to a point when Aβ increase and RA decrease probably lead to a pathological state
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