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1.
Geochem Geophys Geosyst ; 20(8): 4059-4072, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31762710

ABSTRACT

Anhydrous phase B and stishovite formed directly from olivine in experiments at 14 GPa and 1400 °CThe structure of anhydrous phase B is determined ab initio from precession electron diffraction tomography in transmission electron microscopyElastic and seismic properties of anhydrous phase B are calculated.


We have performed an extensive characterization by transmission electron microscopy (including precession electron diffraction tomography and ab initio electron diffraction refinement as well as electron energy loss spectroscopy) of anhydrous phase B (Anh­B) formed directly from olivine at 14 GPa, 1400 °C. We show that Anh­B, which can be considered as a superstructure of olivine, exhibits strong topotactic relationships with it. This lowers the interfacial energy between the two phases and the energy barrier for nucleation of Anh­B, which can form as a metastable phase. We have calculated the elastic and seismic properties of Anh­B. From the elastic point of view, Anh­B appears to be more isotropic than olivine. Anh­B displays only a moderate seismic anisotropy quite similar to the one of wadsleyite.


Anhydrous phase B (Anh­B) is a dense magnesium silicate with composition (Mg, Fe)14Si5O24, which is expected to form in Mg­rich or Si­depleted regions of the mantle. We show that due to strong crystallographic similarities with the crystal structure of olivine, it can form directly from it as a metastable phase. We show that Anh­B exhibits a moderate seismic anisotropy, which makes its detection difficult in the mantle.

4.
Philos Trans A Math Phys Eng Sci ; 375(2086)2017 Feb 13.
Article in English | MEDLINE | ID: mdl-28025294

ABSTRACT

Nucleation mechanisms occurring during dynamic recrystallization play a crucial role in the evolution of microstructures and textures during high temperature deformation. In polycrystalline ice, the strong viscoplastic anisotropy induces high strain heterogeneities between grains which control the recrystallization mechanisms. Here, we study the nucleation mechanisms occurring during creep tests performed on polycrystalline columnar ice at high temperature and stress (T=-5°C;σ=0.5 MPa) by post-mortem analyses of deformation microstructures using cryogenic electron backscatter diffraction. The columnar geometry of the samples enables discrimination of the nuclei from the initial grains. Various nucleation mechanisms are deduced from the analysis of the nuclei relations with the dislocation sub-structures within grains and at grain boundaries. Tilt sub-grain boundaries and kink bands are the main structures responsible for development of polygonization and mosaic sub-structures. Nucleation by bulging at serrated grain boundaries is also an efficient nucleation mechanism near the grain boundaries where strain incompatibilities are high. Observation of nuclei with orientations not related to the 'parent' ones suggests the possibility of 'spontaneous' nucleation driven by the relaxation of the dislocation-related internal stress field. The complexity of the nucleation mechanisms observed here emphasizes the impact of stress and strain heterogeneities on dynamic recrystallization mechanisms.This article is part of the themed issue 'Microdynamics of ice'.

5.
High Blood Press Cardiovasc Prev ; 23(4): 373-380, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27623974

ABSTRACT

INTRODUCTION: LV dysfunction develops early in hypertension, even previously to left ventricular remodeling. AIMS: To determine the frequency of morphologic and functional heart abnormalities associated to abnormal modified Tei Index in untreated hypertensive (HBP) patients (p) with preserved ejection fraction (pEF). METHODS: Case-control study. Three groups: (1) HBP without left ventricular hypertrophy (LVH); (2) HBP with LVH; (3) non-HBP controls. Ejection fraction >54 % identified pEF. LVH measured by Devereux method. Systolic and diastolic functions assessed by standard echocardiography and tissue Doppler. 2013 ESH/ESC Hypertension Guidelines normal values were considered. Tei index measured at the lateral and septal LV walls in apical 4-chamber view by tissue Doppler, value >0.40 considered abnormal. STATISTICAL ANALYSIS: multifactorial ANOVA test adjusted by sex and age, p < 0.05 statistically significant. RESULTS: The study included 14 controls, 88 HBP p without LVH, and 19 HBP p with LVH. The HBP p sample mean age was 58.7 ± 13.5 years and 52 (44.1 %) were males. Mean Tei Index was 0.35 ± 0.03 in controls; 0.42 ± 0.05 in HBP without LVH; and 0.42 ± 0.06 in HBP with LVH (p < 0.025). Abnormal Tei Index was present in 2p (14.3 %) controls; 64 p (72.7 %) HBP without LVH; and 15 p (78.9 %) HBP with LVH (p < 0.0009). Tissue Doppler's wave was 8.4 ± 0.9 cm/s in controls; 8 ± 1.6 cm/s in HBP without LVH and 7.8 ± 1.1 cm/s in HBP with LVH. CONCLUSIONS: (1) Left ventricular dysfunction is frequent in HBP p, even without LVH; (2) modified tissue Doppler Tei index is a useful tool for the diagnosis of left ventricular dysfunction.


Subject(s)
Blood Pressure , Hypertension/complications , Hypertrophy, Left Ventricular/etiology , Ventricular Dysfunction, Left/etiology , Ventricular Function, Left , Ventricular Remodeling , Adult , Aged , Case-Control Studies , Cross-Sectional Studies , Echocardiography, Doppler, Color , Female , Humans , Hypertension/diagnosis , Hypertension/physiopathology , Hypertrophy, Left Ventricular/diagnosis , Hypertrophy, Left Ventricular/physiopathology , Male , Middle Aged , Multivariate Analysis , Prospective Studies , Risk Factors , Ventricular Dysfunction, Left/diagnosis , Ventricular Dysfunction, Left/physiopathology
6.
Nanotechnology ; 27(38): 385503, 2016 Sep 23.
Article in English | MEDLINE | ID: mdl-27532770

ABSTRACT

A new method, which is easily scalable to large scale production, has been developed to obtain gas sensor devices based on zinc oxide (ZnO) nanostructures with a 'tetrapod' shape. The method can be easily extended to other kinds of nanostructures and is based on the deposition of ZnO nanostructures through polymeric masks by centrifugation, directly onto properly designed MEMS micro-hotplates. The micromachined devices, after the mask is peeled off, are ready for electrical bonding and sensing test. Sensor response has been successfully measured for some gases and volatile organic compounds with different chemical properties (ethanol, methane, nitrogen dioxide, hydrogen sulfide).

7.
Hipertens. riesgo vasc ; 33(1): 14-20, ene.-mar. 2016. tab, graf
Article in English | IBECS | ID: ibc-149329

ABSTRACT

Background: Prediction charts allow treatment to be targeted according to simple markers of cardiovascular risk; many algorithms do not recommend screening asymptomatic target organ damage which could change dramatically the assessment. Objective: To demonstrate that target organ damage is present in low cardiovascular risk hypertensive patients and it is more frequent and severe as global cardiovascular risk increases. Methods: Consecutive hypertensive patients treated at a single Latin American center. Cardiovascular risk stratified according to 2013 WHO/ISH risk prediction chart America B. Left ventricular mass assessed by Devereux method, left ventricular hypertrophy considered >95 g/m2 in women and >115 g/m2 in men. Transmitral diastolic peak early flow velocity to average septal/lateral peak early diastolic relaxation velocity (E/e’ ratio) measured cut off value >13. Systolic function assessed by tissue Doppler average interventricular septum/lateral wall mitral annulus rate systolic excursion (s wave). Results: A total of 292 patients were included of whom 159 patients (54.5%) had cardiovascular risk of < 10%, 90 (30.8%) had cardiovascular risk of 10-20% and 43 (14.7%) had cardiovascular risk of >20%. Left ventricular hypertrophy was detected in 17.6% low risk patients, 27.8% in medium risk and 23.3% in high risk (p < 0.05), abnormal E/e′ ratio was found in 13.8%, 31.1% and 27.9%, respectively (p < 0.05). Mean s wave was 8.03 + 8, 8.1 + 9 and 8.7 + 1 cm/s for low, intermediate and high risk patients, respectively (p < 0.025). Conclusions: Target organ damage is more frequent and severe in high risk; one over four subjects was misclassified due to the presence of asymptomatic target organ damage


Antecedentes: Las tablas de riesgo cardiovascular dirigen el tratamiento según marcadores clínicos sencillos. Muchos algoritmos no recomiendan el cribado rutinario del daño de órgano blanco asintomático que podría cambiar drásticamente la estratificación. Objetivos: Demostrar que el daño en órgano blanco es altamente prevalente en el bajo riesgo cardiovascular y más frecuente y severo en la medida en que este aumenta. Material y métodos: Un total de 292 pacientes hipertensos consecutivos no tratados en un único centro latinoamericano. Riesgo cardiovascular estratificado según Guía 2013 OMS/ISH América B. Masa ventricular izquierda evaluada por método de Devereux, hipertrofia ventricular izquierda >95 g/m2 mujeres y >115 g/m2hombres. Se midió relación velocidad pico diastólico transmitral con doppler y velocidad diastólica precoz septal y lateral del anillo mitral con doppler tisular (relación E/e′), valor de corte >13. Función sistólica evaluada por doppler tisular como tasa de excursión tabique interventricular y pared lateral (onda s). Resultados: Un total de 159 pacientes (54,5%) presentaron riesgo cardiovascular <10%; 90 (30,8%) riesgo cardiovascular entre el 10% y el <20% y 43 (14,7%) presentaron un riesgo cardiovascular >20%. La hipertrofia ventricular izquierda en 17,6% pacientes fue de bajo riesgo, en el 27,8% de riesgo intermedio y en el 23,3% de alto riesgo (p < 0,05), con relación E/e′ anormal 13,8; 31,1 y 27,9%, respectivamente (p < 0,05). La onda s promedio fue de 8,03 + 8; 8,1 + 9 ; y 8,7 + 1 cm/seg para riesgo bajo, intermedio y alto, respectivamente (p < 0,025). Conclusiones: El daño en órgano blanco fue más frecuente y severo en alto riesgo; uno de cada 4 sujetos fue clasificado erróneamente debido a presencia de daño en órgano blanco subclínico


Subject(s)
Humans , Cardiovascular Diseases/prevention & control , Hypertrophy, Left Ventricular/prevention & control , Ventricular Dysfunction, Left/prevention & control , Hypertension/prevention & control , Risk Factors , Risk Adjustment/classification
8.
Hipertens Riesgo Vasc ; 33(1): 14-20, 2016.
Article in English | MEDLINE | ID: mdl-26521088

ABSTRACT

BACKGROUND: Prediction charts allow treatment to be targeted according to simple markers of cardiovascular risk; many algorithms do not recommend screening asymptomatic target organ damage which could change dramatically the assessment. OBJECTIVE: To demonstrate that target organ damage is present in low cardiovascular risk hypertensive patients and it is more frequent and severe as global cardiovascular risk increases. METHODS: Consecutive hypertensive patients treated at a single Latin American center. Cardiovascular risk stratified according to 2013 WHO/ISH risk prediction chart America B. Left ventricular mass assessed by Devereux method, left ventricular hypertrophy considered >95g/m(2) in women and >115g/m(2) in men. Transmitral diastolic peak early flow velocity to average septal/lateral peak early diastolic relaxation velocity (E/e' ratio) measured cut off value >13. Systolic function assessed by tissue Doppler average interventricular septum/lateral wall mitral annulus rate systolic excursion (s wave). RESULTS: A total of 292 patients were included of whom 159 patients (54.5%) had cardiovascular risk of <10%, 90 (30.8%) had cardiovascular risk of 10-20% and 43 (14.7%) had cardiovascular risk of >20%. Left ventricular hypertrophy was detected in 17.6% low risk patients, 27.8% in medium risk and 23.3% in high risk (p<0.05), abnormal E/e' ratio was found in 13.8%, 31.1% and 27.9%, respectively (p<0.05). Mean s wave was 8.03+8, 8.1+9 and 8.7+1cm/s for low, intermediate and high risk patients, respectively (p<0.025). CONCLUSIONS: Target organ damage is more frequent and severe in high risk; one over four subjects was misclassified due to the presence of asymptomatic target organ damage.


Subject(s)
Cardiovascular Diseases/epidemiology , Hypertrophy, Left Ventricular , Diastole , Echocardiography, Doppler , Female , Humans , Male , Risk Factors , Systole , Ventricular Dysfunction, Left/diagnosis , Ventricular Function, Left , World Health Organization
9.
Hipertens. riesgo vasc ; 31(4): 119-124, oct.-dic. 2014. graf, tab
Article in Spanish | IBECS | ID: ibc-129658

ABSTRACT

Introducción: El diagnóstico de hipertrofia ventricular izquierda (HVI) está basado en consensos. Objetivo: Determinar la relevancia de los cambios en los criterios de las guías ESH/ESC 2007 vs. 2013. Material y métodos: Ecocardiograma 2D y M; concordancia del índice de masa ventricular izquierda (IMVI) entre ESH/ESC 2007 y 2013. Análisis estadístico: Test de t de Student. Razón y coeficiente de correlación intraclase. Significación estadística p < 0,05. Resultados: Un total de 503 pacientes, con IMVI promedio ESH/ESC 2007 101 + 21,8 g/m2 vs ESH/ESC 2013 88 + 17,6 g/m2 (p < 0,001). Coeficiente de correlación r = 0,856 (p < 0,0005), razón 0,88 + 0,3. Frecuencia de HVI ESH/ESC 2007 23,9% vs ESH/ESC 2013 20,3% (p = NS). ESH/ESC 2007 y 2013 coincidieron en el diagnóstico en 94,4%. Conclusiones: 1) El IMVI es un 12% menor con la guía ESH/ESC 2013; 2) el diagnóstico es concordante en el 94,4% de los casos


Introduction: The diagnosis of left ventricular hypertrophy (LVH) is consensus based. Objective: To determine the relevance of the changes in criteria from the 2007 to 2013 ESH/ESC. Material and methods: A 2D and M echocardiography. The concordance index between the 2007 and 2013 ESH/ESC for left ventricular mass index (LVMI) was analyzed. Statistical análisis: Student t test. Intraclass correlation ratio and coefficient. Statistical significance P < .05. Results: A total of 503 patients, with mean LVMI ESH/ESC 2007 101 + 21.8 g/m2 and ESH/ESC 2013 88.8 + 17.6 g/m2 (P < .001). Correlation coefficient r = .856 (P < .0005) and ratio 0.88 + 0.3. 2007ESH/ESC LVH was 23.9% and 2013 ESH/ESC 20.3% (p = NS). The 2007 and 2013 ESH/ESC measurements coincided in 94.4% of the diagnoses. Conclusions: 1) On an average, LVMI was 12% less with the 2013 ESH/ESC Guidelines. 2) The diagnosis is in agreement between the guidelines in 94.4% of cases


Subject(s)
Humans , Hypertrophy, Left Ventricular/diagnosis , /physiopathology , Hypertension/physiopathology , Reference Values , Reproducibility of Results , Epidemiology, Descriptive
10.
J Clin Microbiol ; 52(6): 2231-4, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24622106

ABSTRACT

Anaplasma platys is an obligate intracellular rickettsial pathogen that infects platelets of dogs, forming basophilic intracellular morulae. In the present report, cellular inclusions were documented in bone marrow thrombocyte precursors of two young naturally infected dogs, indicating that A. platys can infect megakaryocytes and promegakaryocytes.


Subject(s)
Anaplasma/isolation & purification , Anaplasmosis/pathology , Bone Marrow/microbiology , Dog Diseases/pathology , Megakaryocytes/microbiology , Anaplasmosis/microbiology , Animals , Dog Diseases/microbiology , Dogs , Female , Male
11.
J Gerontol A Biol Sci Med Sci ; 66(6): 620-6, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21382886

ABSTRACT

Sarcopenia is the loss of muscle size and function during ageing. The aim of this study was to test whether serum concentrations of myostatin and interacting proteins (GASP-1, FLRG, and follistatin) differed between young and elderly sarcopenic men. Isometric knee extensor maximal voluntary contraction and quadriceps cross-sectional area (magnetic resonance imaging measurement) were significantly higher in young (22 ± 2 years; 266 ± 54 N/m; 8,686 ± 1,154 mm(2)) than in mildly sarcopenic (69 ± 3 years; 183 ± 17 N/m; 6,621±718 mm(2)) and severely sarcopenic men (76 ± 6 years; 127 ± 23 N/m; 5,846 ± 591 mm(2)), respectively (p ≤ .01 for all comparisons). There was a trend (p = .06) toward higher FLRG in young (20 ± 8 ng/mL) than in mildly (15 ± 6 ng/mL) and severely sarcopenic men (17 ± 8 ng/mL). Myostatin, follistatin, GASP-1, tumor necrosis factor α, and interleukin-6 did not differ significantly. Insulin-like growth factor-1 and free testosterone were both significantly lower in sarcopenic men (p < .001). This suggests that altered serum concentrations of myostatin and myostatin-interacting proteins are not contributing to sarcopenia with the possible exception of FLRG.


Subject(s)
Myostatin/blood , Sarcopenia/blood , Adult , Aged , Follistatin/blood , Follistatin-Related Proteins/blood , Humans , Insulin-Like Growth Factor I/analysis , Intercellular Signaling Peptides and Proteins , Interleukin-6/blood , Male , Muscle Contraction , Proteins/analysis , Testosterone/blood
12.
Minerva Endocrinol ; 32(3): 231-6, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17912159

ABSTRACT

Pituitary carcinomas are very rare tumors, nearly always presenting as widely invasive masses, although the hallmark of these lesions is the finding of distant metastases. One third of reported cases are prolactin (PRL)-secreting tumors. We report the case of a fatal pituitary carcinoma evolving within 4 years from a PRL-secreting microadenoma. A 22-year-old woman presented because of galactorrhea. Evaluation of the patient disclosed slight hyperprolactinemia and magnetic resonance imaging (MRI) showed a 7-mm intrapituitary lesion, which responded to treatment with cabergoline. About 4 years after the first evaluation she developed sudden headache, ptosis, and diplopia in the right eye. MRI disclosed the growth of a large pituitary mass, invading the right cavernous sinus. Despite two trans-sphenoidal surgical procedures followed by gamma-knife radiosurgery, the patient showed rapid local progression of the tumor and the occurrence of new lung lesions, probably of metastatic nature. The patient died 7 months after the development of her first neurological symptoms because of tumor apoplexy and subsequent subarachnoid hemorrhage. This case represents the first documented rapid evolution from a microprolactinoma initially responding to dopamine agonists to a fatal pituitary carcinoma.


Subject(s)
Carcinoma/pathology , Pituitary Neoplasms/pathology , Prolactinoma/pathology , Adult , Cabergoline , Combined Modality Therapy , Disease Progression , Dopamine Agonists/therapeutic use , Drug Resistance , Ergolines/therapeutic use , Fatal Outcome , Female , Humans , Octreotide/therapeutic use , Pituitary Apoplexy/etiology , Pituitary Neoplasms/complications , Pituitary Neoplasms/drug therapy , Pituitary Neoplasms/radiotherapy , Pituitary Neoplasms/surgery , Prolactinoma/complications , Prolactinoma/drug therapy , Prolactinoma/radiotherapy , Prolactinoma/surgery , Radiosurgery , Subarachnoid Hemorrhage/etiology
14.
Aliment Pharmacol Ther ; 23(11): 1649-53, 2006 Jun 01.
Article in English | MEDLINE | ID: mdl-16696816

ABSTRACT

BACKGROUND: The aetiology of intrahepatic cholestasis of pregnancy is unknown, but more than 10 different MDR3 gene mutations have recently been identified. AIM: To evaluate the genetic contribution of the MDR3 gene in the pathogenesis of intrahepatic cholestasis of pregnancy in Italian subjects. METHODS: We performed a multicentre prospective case-control study, enrolling 80 women with intrahepatic cholestasis of pregnancy at the third trimester of pregnancy and 80 pregnant women without intrahepatic cholestasis of pregnancy. Genomic DNA was extracted from peripheral venous blood leucocytes using standard procedures. The polymerase chain reaction was used to amplify exon 14 of the MDR3 gene and the polymerase chain reaction products were sequenced using a Big Dye Terminator Cycle Sequencing kit. RESULTS: Three novel non-synonymous heterozygous mutations in exon 14 were found (4%; E528D, R549H, G536R) among the 80 intrahepatic cholestasis of pregnancy patients, whereas the pregnant controls were all negative for exon 14 polymorphisms. The three patients involved had normal GGT and bilirubin, but high levels of both ALT and serum bile acids. One had cholesterol bile stones. The outcome of pregnancy was normal for two (with vaginal delivery), while foetal distress was recorded in the third. CONCLUSIONS: These three novel mutations add further information on the involvement of the MDR3 gene in intrahepatic cholestasis of pregnancy. As in other studies, we found only heterozygous mutations that could cause an impaired transport protein function, not its absence (which is responsible for more severe liver disease). Different genetic backgrounds might justify the presence of novel MDR3 gene mutations.


Subject(s)
Cholestasis, Intrahepatic/genetics , Genes, MDR/genetics , Pregnancy Complications/genetics , ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , Adult , Case-Control Studies , DNA Mutational Analysis , Female , Humans , Middle Aged , Mutation/genetics , Polymerase Chain Reaction , Pregnancy , Pregnancy Outcome , Prospective Studies
15.
Eur J Neurol ; 13(3): 240-3, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16618339

ABSTRACT

Spinal primitive neuroectodermal tumors (PNET) are very rare tumors, and intramedullary localization is even less common. Indeed, amongst the 23 cases of the spinal PNET described in the literature, only eight cases had an intramedullary localization. Following the WHO 2000 classification, PNETs have been considered embryonal tumors composed of undifferentiated neuroepithelial cells with a capacity of differentiation into different cellular lines, such as astrocytic, ependymal, melanotic and muscular. They have been considered to arise from a neoplastic transformation of primitive neuroepithelial cells, thereby making their presence possible in any part of the central nervous system. The optimal treatment for these malignant tumors is not yet clear, although, over the years, radiotherapy has been considered the best treatment for spinal PNETs. The described case is that of a 38-year-old man with a primary intra-extramedullary PNET, treated by laminectomy, open biopsy and chemotherapy. The patient, 18 months after the onset of his symptomatology, died without cerebral tumor involvement.


Subject(s)
Brain Neoplasms , Laminectomy/methods , Neuroectodermal Tumors, Primitive , Adolescent , Adult , Aged , Brain Neoplasms/pathology , Brain Neoplasms/surgery , Child , Child, Preschool , Female , Follow-Up Studies , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neuroectodermal Tumors, Primitive/pathology , Neuroectodermal Tumors, Primitive/surgery
17.
Minerva Stomatol ; 53(10): 603-9, 2004 Oct.
Article in English, Italian | MEDLINE | ID: mdl-15531875

ABSTRACT

In Summer 2002, a patient with frequent epistaxis was admitted to the San Gerardo Hospital. Local examination showed a big mass in the nasal fossa. TC and RMN revealed a diffuse erosion of the palatal bone and infiltration of the maxilla. The tumor was removed and histological examination showed a gland carcinoma. The young age of the patient and the need of an adequate bone reconstruction led to use osteoperiosteal calf bone graft. Subsequently, using local anesthesia, 6 implants were positioned. After normal healing and the period of osteointegration, a Toronto bridge was made on implants that the patient wears with no problem.


Subject(s)
Adenocarcinoma, Clear Cell/surgery , Palatal Neoplasms/surgery , Prostheses and Implants , Salivary Gland Neoplasms/surgery , Adenocarcinoma, Clear Cell/rehabilitation , Adult , Dental Prosthesis , Female , Humans , Palatal Neoplasms/rehabilitation , Salivary Gland Neoplasms/rehabilitation
18.
Nature ; 411(6839): 783-6, 2001 Jun 14.
Article in English | MEDLINE | ID: mdl-11459053

ABSTRACT

Heat transfer in the mantle is a key process controlling the Earth's dynamics. Upper-mantle mineral phases, especially olivine, have been shown to display highly anisotropic thermal diffusivity at ambient conditions, and seismic anisotropy data show that preferred orientations of olivine induced by deformation are coherent at large scales (>50 km) in the upper mantle. Thus heat transport in the upper mantle should be anisotropic. But the thermal anisotropy of mantle minerals at high temperature and its relationship with deformation have not been well constrained. Here we present petrophysical modelling and laboratory measurements of thermal diffusivity in deformed mantle rocks between temperatures of 290 and 1,250 K that demonstrate that deformation may induce a significant anisotropy of thermal diffusivity in the uppermost mantle. We found that heat transport parallel to the flow direction is up to 30 per cent faster than that normal to the flow plane. Such a strain-induced thermal anisotropy implies that the upper-mantle temperature distribution, rheology and, consequently, its dynamics, will depend on deformation history. In oceans, resistive drag flow would result in lower vertical diffusivities in both the lithosphere and asthenosphere and hence in less effective heat transfer from the convective mantle. In continents, olivine orientations frozen in the lithosphere may induce anisotropic heating above mantle plumes, favouring the reactivation of pre-existing structures.

19.
Eur J Obstet Gynecol Reprod Biol ; 89(1): 59-61, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10733025

ABSTRACT

Spinal cord compression by epidural metastasis is considered an exceptional complication in patients with cervical carcinoma. We report three patients treated for a cervical carcinoma who developed epidural metastasis with spinal cord compression at 9, 25 and 48 months after primary treatment of the uterine malignancy. All patients had poorly-differentiated adenocarcinomas with lymphovascular space invasion, and two had lymph node metastasis. All patients underwent emergency decompressive laminectomy followed by radiotherapy and a partial recovery of the neurological function was achieved. In two patients the spinal cord was the only site of recurrent disease, whereas the other had lung and brain metastasis at the time of epidural involvement diagnosis. All three patients, however, died of disseminated disease. Surgical decompression followed by radiation therapy may result in a complete preservation of the neurologic functions in patients with spinal cord compression secondary to metastatic carcinoma of the uterine cervix. Considering the propensity for disseminated disease, long term survival might be achieved only with the use of effective chemotherapy.


Subject(s)
Epidural Neoplasms/secondary , Spinal Cord Compression/etiology , Spinal Cord Compression/surgery , Uterine Cervical Neoplasms , Adenocarcinoma/complications , Adenocarcinoma/radiotherapy , Adenocarcinoma/secondary , Adult , Brain Neoplasms/secondary , Epidural Neoplasms/complications , Epidural Neoplasms/radiotherapy , Fatal Outcome , Female , Humans , Laminectomy , Lung Neoplasms/secondary , Lymphatic Metastasis , Middle Aged , Uterine Cervical Neoplasms/radiotherapy , Uterine Cervical Neoplasms/surgery
20.
Nephrol Dial Transplant ; 14(6): 1536-40, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10383021

ABSTRACT

BACKGROUND: The tenet that peritoneal dialysis is capable of either normalizing or improving blood pressure control in uraemic patients is based on outdated or monocentric experiences. Therefore, we assessed the prevalence of hypertension and the efficacy of antihypertensive therapy in a large, multicentric cohort of patients on peritoneal dialysis. METHODS: Twenty seven out of the 50 centres belonging to the Italian Co-operative Peritoneal Dialysis Study Group took part in the study. The main patient selection criteria were: peritoneal dialysis therapy for at least 3 months and no peritonitis or changes in dialysis technique for at least 1 month. Clinical blood pressure was measured according to WHO/ISH guidelines. Ambulatory blood pressure monitoring was carried out using a SpaceLabs 90207 recorder. Hypertension was defined according to WHO/ISH criteria and staged according to the criteria of the Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure (JNC), 5th Report. Ambulatory blood pressure monitoring recordings were used to evaluate white-coat hypertension, blood pressure load and the dipping phenomenon. RESULTS: Five hundred and four subjects were evaluated. Hypertension was prevalent in 88.1% of the population, and 362 out of 444 hypertensive patients were on antihypertensive therapy. JNC staging revealed that 188 patients had moderate to severe hypertension. Blood pressure load was pathological in 77.3% of the patients receiving antihypertensive treatment. White-coat hypertension was identified in 9.1% of the hypertensive patients not on antihypertensive therapy, and 53.1% of the patients were non-dippers. CONCLUSIONS: The study demonstrates that hypertension is a dramatic, unsolved problem in uraemic patients treated with peritoneal dialysis, and casts doubts on the effectiveness of our current peritoneal dialysis strategies and pharmacological management of hypertension.


Subject(s)
Hypertension/epidemiology , Peritoneal Dialysis/adverse effects , Adult , Aged , Blood Pressure Monitoring, Ambulatory , Female , Humans , Hypertension/drug therapy , Male , Middle Aged , Prevalence
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