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1.
Int J Phytoremediation ; 18(6): 626-33, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26344169

RESUMO

The objective of this study was to monitor and assess environmental impacts of reclaimed wastewater (RW), used for irrigation of vegetable crops, on soil, crop quality and irrigation equipment. During 2013, effluents of a horizontal sub-surface flow constructed treatment wetland (TW) system, used for tertiary treatment of sanitary wastewater from a small rural municipality located in Eastern Sicily (Italy), were reused by micro-irrigation techniques to irrigate vegetable crops. Monitoring programs, based on in situ and laboratory analyses were performed for assessing possible adverse effects on water-soil-plant systems caused by reclaimed wastewater reuse. In particular, experimental results evidenced that Escherichia coli content found in RW would not present a risk for rotavirus infection following WHO (2006) standards. Irrigated soil was characterized by a certain persistence of microbial contamination and among the studied vegetable crops, lettuce responds better, than zucchini and eggplants, to the irrigation with low quality water, evidencing a bettering of nutraceutical properties and production parameters.


Assuntos
Irrigação Agrícola/métodos , Verduras/química , Águas Residuárias/análise , Irrigação Agrícola/instrumentação , Biodegradação Ambiental , Itália , Verduras/crescimento & desenvolvimento , Verduras/metabolismo , Verduras/microbiologia , Águas Residuárias/microbiologia , Microbiologia da Água , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo , Áreas Alagadas
2.
Nat Prod Res ; 34(1): 187-191, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31135191

RESUMO

Long-chain length (DP) inulin-type fructans show pronounced beneficial effects to colon microbiota. In the past, cardoon roots for inulin production to fortify spaghetti gave very good results, but their harvest requires high costs. The aim of the work was to evaluate different types of inulin, extracted from cardoon roots and buds, topinambur tubers and chicory roots local populations in order to identify crops more suitable for high DP inulin production in Mediterranean environment. The inulin amount resulted in 115 (chicory), 390 (cardoon) and 550 g kg-1 of d.m. (topinambur). Both in cardoon roots and in topinambur tubers the DP was very high. With the aim to produce a functional food, substituting inulin in staple food tubers of topinambur could be a good alternative to cardoon roots, due to the biological cycle of the plant (annual vs poliennal), the lowest costs of harvest and the good amounts of high DP inulin.


Assuntos
Inulina/isolamento & purificação , Cichorium intybus/química , Colo/microbiologia , Cynara/química , Inulina/química , Inulina/economia , Região do Mediterrâneo , Raízes de Plantas/química , Tubérculos/química , Polimerização , Sementes
3.
Proc Nutr Soc ; 78(4): 484-495, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30816080

RESUMO

Knowing who eats what, understanding the various eating habits of different population groups, according to the geographical area, is critical to develop evidence-based policies for nutrition and food safety. The FAO/WHO Global Individual Food consumption data Tool (FAO/WHO GIFT) is a novel open-access online platform, hosted by FAO and supported by WHO, providing access to harmonised individual quantitative food consumption (IQFC) data, especially in low- and middle-income countries (LMIC). FAO/WHO GIFT is a growing repository, which will serve as the global FAO/WHO hub to disseminate IQFC microdata. Currently five datasets from LMIC are available for dissemination, and an additional fifty datasets will be made available by 2022. To facilitate the use of these data by policy makers, ready-to-use food-based indicators are provided for an overview of key data according to population segments and food groups. FAO/WHO GIFT also provides an inventory of existing IQFC data worldwide, which currently contains detailed information on 188 surveys conducted in seventy-two countries. In order for end-users to be able to aggregate the available data, all datasets are harmonised with the European Food Safety Authority's food classification and description system FoodEx2 (modified for global use). This harmonisation is aimed at enhancing the consistency and reliability of nutrient intake and dietary exposure assessments. FAO/WHO GIFT is developed in synergy with other global initiatives aimed at increasing the quality, availability and use of IQFC data in LMIC to enable evidence-based decision-making and policy development for better nutrition and food safety.


Assuntos
Bases de Dados Factuais , Inquéritos sobre Dietas , Ingestão de Energia/fisiologia , Ciências da Nutrição/organização & administração , Exposição Dietética , Ingestão de Alimentos/fisiologia , Inocuidade dos Alimentos , Humanos , Nações Unidas , Organização Mundial da Saúde
4.
Micron ; 124: 102714, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31336336

RESUMO

In Bromeliaceae, various traits have evolved for the uptake and storage of water; however, their roles in bromeliad inflorescences remain unresolved. This study investigates the role of water in the flowers and inflorescences of Nidularium innocentii, and describes water as a protection mechanism. Individuals were divided into groups with and without water provision in inflorescences. Both groups were maintained with water in soil and leaves under the same environmental conditions. During anthesis, individuals were collected, and inflorescences were measured. Another specimen was prepared and scanned using X-ray microtomography (µCT), generating a high-resolution 3D model that was converted into a discretized geometry. Heat transfer finite element analysis (FEA) of the µCT-based geometry was then performed to simulate external temperature dissipation with the presence and absence of water in 3D. Flower size in the control group was significantly larger, and many injuries were observed in the drought group. FEA data indicated that the water environment led to lower temperature variation when compared to the air environment by significantly alleviating thermal amplitude. Water acted as a temperature stabilizer for the inflorescence, while its absence initiated physiological stress responses.


Assuntos
Bromeliaceae/fisiologia , Temperatura Alta , Inflorescência/fisiologia , Estresse Fisiológico , Microtomografia por Raio-X , Secas , Folhas de Planta , Água
6.
J Clin Endocrinol Metab ; 81(10): 3589-93, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8855806

RESUMO

GH is able to promote longitudinal growth in children with GH-deficiency (GHD) and in some children with idiopathic short stature (ISS). The objectives of this study were to evaluate the predictive value of bone and collagen markers on the growth response to GH therapy in children with ISS and with GHD, and to characterize the effects of GH treatment on bone and collagen turnover in children with ISS and with GHD. Twenty prepubertal short, slowly growing, children treated with GH, 15 IU/m2 per week, were studied; of them 13 (10 males) had ISS and 7 (5 males) had GHD. An overnight 12-h urinary collection and a fasting morning blood sample were obtained at baseline, 1, 3, 6, and 12 months of treatment. Urinary levels of collagen cross-links, pyridinoline (Pyd) and deoxypyridinoline (Dpd), and circulating levels of osteocalcin, intact PTH, calcitonin, procollagen type III aminoterminal propeptide (PIIINP), insulin-like growth factor-I, and alkaline phosphatase were determined. Urinary collection was also obtained from 127 healthy children (51 males) aged 6-13 yr. In children with ISS, the changes in Dpd over 1 month of GH therapy were related to the changes in height velocity (HV) over 1 yr of therapy (r = 0.67; P < 0.05); the changes in Pyd after 1 month of GH treatment were related to the changes in HV at 6 months of GH treatment (r = 0.57; P < 0.05). All the other markers evaluated were not related to the HV changes in children with ISS. In children with GHD, the changes in Pyd and in Dpd after 1 month of GH treatment were positively related to the changes in HV after 12 months of therapy (r = 0.82; P < 0.05, and r = 0.82; P < 0.05, respectively). The changes in Pyd after 1 month were also related to the HV changes after 6 months of GH (r = 0.77; P < 0.05). Positive relationships between the HV after 6 months of GH and the increases of PIIINP (r = 0.80; P < 0.05) and osteocalcin (r = 0.77; P < 0.05) after 3 months of GH therapy were observed. All patients showed urinary Dpd and Pyd excretions in the normal range. In patients with ISS, Pyd (P < 0.05), Dpd (P < 0.05), osteocalcin (P < 0.01), PIIINP (P < 0.01), and alkaline phosphatase (P < 0.01) increased longitudinally during the GH treatment and the increments reached a maximum after 3-6 months of therapy. Patients with GHD showed an increase of the same markers but the increases occurred earlier, after 1 month of GH therapy. The collagen cross-links, Pyd and Dpd, could be helpful early markers in predicting the responsiveness to GH therapy in children with ISS and with GHD. GH treatment stimulates bone and collagen metabolism.


Assuntos
Osso e Ossos/metabolismo , Colágeno/urina , Transtornos do Crescimento/tratamento farmacológico , Hormônio do Crescimento Humano/deficiência , Hormônio do Crescimento Humano/uso terapêutico , Compostos de Piridínio/urina , Adolescente , Fosfatase Alcalina/sangue , Aminoácidos/urina , Estatura , Desenvolvimento Ósseo , Remodelação Óssea , Criança , Reagentes de Ligações Cruzadas , Feminino , Transtornos do Crescimento/metabolismo , Transtornos do Crescimento/urina , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Osteocalcina/sangue
7.
Am J Clin Nutr ; 61(6 Suppl): 1338S-1345S, 1995 06.
Artigo em Inglês | MEDLINE | ID: mdl-7754985

RESUMO

Since Keys' first observations in the 1960s, the Mediterranean diet has been under scrutiny by researchers and public health specialists for its health-promoting qualities. Detailed analyses of food surveys carried out in Italy at that time permitted a definition of an Italian-style Mediterranean diet, characterized by low total fat (< 30% of energy), low saturated fat (< 10% of energy), high complex carbohydrates, and high dietary fiber. The importance of the plant components of this dietary pattern became increasingly recognized as a result of advances in the understanding of the pathophysiology of chronic and degenerative diseases. Thus, the Mediterranean diet was found not only to produce favorable effects on blood lipid profiles, but also to protect against oxidative stress and carcinogenesis. However, possible unwanted effects, such as those on micronutrient bioavailability, also must be taken into account. In recent years, despite an increase in consumption of animal foods, the dietary profile of southern Italy has maintained its basic features, and vital statistics still demonstrate a comparative advantage of eating behaviors in Mediterranean countries.


Assuntos
Dieta/tendências , Antioxidantes , Inquéritos sobre Dietas , Europa (Continente)/epidemiologia , Comportamento Alimentar , Nível de Saúde , Humanos , Itália/epidemiologia , Lipídeos/sangue
8.
Eur J Endocrinol ; 138(5): 524-9, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9625363

RESUMO

OBJECTIVE: To assess cortisol concentrations in cord blood and investigate their relationships with the IGF system. STUDY DESIGN: Fifteen newborns with birth weight appropriate for gestational age (AGA) and 30 children with intrauterine growth retardation (IUGR) were studied. Serum samples were collected from umbilical cord blood and cortisol, IGF-I and IGF-binding proteins (IGFBPs)-1 and -3 were measured. IUGR infants were followed up for 3 months with repeated measurements of weight, supine length and knee-heel length (by knemometry). RESULTS: IUGR newborns showed significantly greater concentrations of IGFBP-1 (P<0.0001) and lower concentrations of IGF-I (P< 0.0001) and IGFBP-3 (P< 0.0001) than did controls. In AGA children, cortisol correlated inversely with IGF-I (r=-0.75, P< 0.002) and directly with IGFBP-1 (r=0.52, P <0.05), whereas no correlation between cortisol and IGF system-related variables was observed in IUGR. Finally, in IUGR children an inverse correlation was found between length gain in the first trimester of life and cortisol concentrations at birth (r=-0.54, P < 0.005). CONCLUSIONS: Cortisol might be a physiological regulator of fetal growth, at least in the last part of pregnancy, by modulating IGF-I and IGFBP-1 release under conditions of fetal stress. In IUGR children, a rearrangement of this growth control mechanism seems to occur. The close inverse relationship of cortisol with linear growth, if confirmed by large-scale studies, suggests cord blood cortisol to be potentially predictive of early postnatal catch-up growth in IUGR infants.


Assuntos
Sangue Fetal/metabolismo , Hidrocortisona/sangue , Recém-Nascido de Baixo Peso/sangue , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Humanos , Modelos Lineares
9.
Metabolism ; 49(11): 1467-72, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11092513

RESUMO

This study assessed growth and skeletal metabolism in full-term newborns with intrauterine growth retardation (IUGR) and determined the value of the urinary excretion of collagen cross-links in predicting postnatal catch-up growth. We studied 38 newborns (16 females) born at term with a birth weight less than the 10th centile of the reference and a ponderal index ([PI] 100 x weight in g/length in cm3) of 2.27 +/- 0.19. The sample was divided into 23 children with proportionate ([P] PI > or = 10th centile of the reference) and 15 with nonproportionate ([NP] PI < 10th centile of the reference) IUGR. The weight, head circumference, length, and knee-heel length of the newborns at days 7, 14, 30, 60, and 90 were measured. The height of 23 of the 38 children was also assessed at 27 +/- 6 months of life. Urinary collagen cross-links were analyzed by high-performance liquid chromatography at day 14 and day 60. Most of the infants (68%) underwent catch-up growth, and the growth performance at 3 months was independent of the proportions at birth. Children who did not show catch-up growth in the first trimester of life failed to normalize in height in the following 2 years. The urinary excretion of pyridinoline (Pyd) was not related to the anthropometric measurements. In P children, urinary excretion of deoxypiridinoline (Dpd) at day 14 significantly correlated with the gain in length during the first 3 months, accounting for 25% of the variance. In NP children, these correlations between urinary Dpd and the gain in length were not significant. The evaluation of urinary Dpd excretion at 2 weeks of age might help to determine the therapeutic regimen in IUGR children.


Assuntos
Desenvolvimento Infantil , Colágeno/metabolismo , Retardo do Crescimento Fetal , Antropometria , Colágeno/química , Colágeno/urina , Humanos , Recém-Nascido
10.
Eur J Clin Nutr ; 56 Suppl 4: S16-20, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12556942

RESUMO

Probiotic bacteria are used for production of fermented dairy products. The use of probiotic bacteria has the potential to replenish the natural intestinal flora of the body. These bacteria competitively inhibit the growth and colonization of pathogenic bacteria. Breastmilk is the best food for babies, also from a probiotic point of view. Human milk, in fact, contains many substances that stimulate the growth of bifidobacteria in vitro and in the small intestine of infants. Improvement of lactose digestion and avoidance of symptoms of intolerance in lactose malabsorbers are the most profoundly studied health-relevant effects of fermented milk. In fact fermented milks are nutritionally similar to unfermented milk, except that some of lactose is broken down to glucose and galactose. The role of fermented milk in complementary feeding and in particular for the prevention of anaemia is an innovative theme, recently focused. Iron deficiency in infants and young children is widespread and has serious consequences for child health. Prevention of iron deficiency should therefore be given high priority. The too-early introduction of unmodified cow's milk and milk products is an important nutritional risk factors for the development of iron-deficiency anaemia. Fermented milks represent an excellent source of nutrients such as calcium, protein, phosphorus and riboflavin. During the fermentation of milk, lactic acid and other organic acids are produced and these increase the absorption of iron. If fermented milk is consumed at mealtimes, these acids are likely to have a positive effect on the absorption of iron from other foods.


Assuntos
Anemia Ferropriva/prevenção & controle , Alimentos Infantis/microbiologia , Fenômenos Fisiológicos da Nutrição do Lactente/fisiologia , Leite/microbiologia , Animais , Ásia Central , Europa Oriental , Comportamento Alimentar/fisiologia , Fermentação/fisiologia , Humanos , Lactente
11.
Eur J Clin Nutr ; 48 Suppl 3: S165-78, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7843154

RESUMO

A method has been devised to quantify the effect of seasonal environmental stress on nutritional well-being and to estimate the proportion of Third World populations at risk of functional deterioration. An Index of Agro-Climatic Seasonality, IACS--a measure of potential agricultural biomass availability--has been developed from agro-climatic data. IACS was found to be highly correlated with the seasonal weight loss of adults in rural Third World communities. This relationship was then used to predict the existence and severity of seasonal energy stress incurred by the adult population of Third World countries at any given body mass index (BMI). The average weight loss recorded in all seasonality studies was calculated; this value was used to specify, in combination with BMI, a condition of moderate seasonal energy stress. This grade of energy stress involved a loss of about 2% fat-free mass. The risk of greater energy stress, with larger losses of lean tissue, was specified as severe when predicted weight changes exceeded the maximum losses of weight recorded--at any given BMI--in Third World rural communities. The global dimensions of seasonality were then calculated by enumerating the individuals who--by the combined criteria of the BMI and the IACS of the habitat--fell into the categories of moderate and severe seasonality risk. On this basis, 65% of the rural adult population in the Third World run the risk of at least moderate seasonal energy stress, while 45% fall into the severe stress category. Of these 25% qualify as true seasonal 'casualties' because their body weight loss shifts their BMI from the normal range of nutritional status into the category of chronic energy deficiency.


Assuntos
Índice de Massa Corporal , Desnutrição Proteico-Calórica/epidemiologia , Estações do Ano , Agricultura/estatística & dados numéricos , Países em Desenvolvimento , Feminino , Humanos , Modelos Lineares , Masculino , Estado Nutricional , Desnutrição Proteico-Calórica/diagnóstico , Medição de Risco , Fatores de Risco , Saúde da População Rural , Índice de Gravidade de Doença
12.
Eur J Clin Nutr ; 47(12): 840-50, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8156981

RESUMO

A survey of the nutritional status of subsistence farmers was conducted over 13 months in a rural area of Ethiopia characterized by moderate climatic seasonality and intensive land exploitation. Bi-monthly questionnaires on food consumption, time allocation, agricultural production and cash flow were administered to 203 households and anthropometry performed on 1407 individuals. Comparison of post-harvest and pre-harvest anthropometry was made on 672 individuals (48% of the sample). In children, seasonal changes in the Z-score of weight-for-height were small and not significant. Height growth velocity showed instead a marked seasonal pattern, with values close to normal (-0.2 SD units) in July to December, a period characterized by better food availability, and lower values (-3.0 SD units) in January to June, a period characterized by intensive farm labour and heavy rains. Among the adults, body weight was highest in the post-harvest season (December) and decreased by 1.5 +/- 2.3 kg in men and 1.3 +/- 2.6 kg in women to the yearly minimum in the pre-harvest season (June). The paper shows that in this area children and adults both suffer from exposure to seasonal energy stress. The change in weight-for-height Z-score observed in children and the body weight loss observed in adults was greater in individuals of low socio-economic status and, within the same socio-economic level, in individuals with better nutritional status.


Assuntos
Transtornos da Nutrição Infantil/epidemiologia , Comportamento Alimentar , Estado Nutricional , Desnutrição Proteico-Calórica/epidemiologia , Saúde da População Rural , Estações do Ano , Adolescente , Adulto , Agricultura , Criança , Transtornos da Nutrição Infantil/diagnóstico , Transtornos da Nutrição Infantil/etiologia , Transtornos da Nutrição Infantil/metabolismo , Pré-Escolar , Metabolismo Energético , Etiópia/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Avaliação Nutricional , Inquéritos Nutricionais , Desnutrição Proteico-Calórica/diagnóstico , Desnutrição Proteico-Calórica/etiologia , Desnutrição Proteico-Calórica/metabolismo , Fatores Socioeconômicos
13.
Eur J Clin Nutr ; 47(12): 851-62, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8156982

RESUMO

The household integrated response to seasonal fluctuations in food availability and work load was assessed in a longitudinal study in two villages of southern Ethiopia. The household response to energy stress was estimated by pooling weight changes of all members of the family, accounting for the diverse biological and functional meaning of weight losses of different age and sex groups, and levels of nutritional status. On average, seasonal energy stress experienced by the households was modest (3.3%, P < 0.05 by Tukey test). The cumulative weight change of poor households was twice as large as that of rich ones, and evidence was obtained of their further deterioration over the following agricultural year. Household food availability fluctuated seasonally, with evident socio-economic gradient: in the early pre-harvest season food stocks of poor households were 6.5 times smaller than those of better-off families (P < 0.001 by ANOVA). Unlike rich households, poor families markedly decreased the time devoted to agriculture in the pre-harvest season. Crop selection, quality of land management and time employed in agricultural work might have synergistically concurred to cause the stress situation.


Assuntos
Transtornos da Nutrição Infantil/epidemiologia , Abastecimento de Alimentos , Desnutrição Proteico-Calórica/epidemiologia , Saúde da População Rural , Estações do Ano , Carga de Trabalho , Adolescente , Adulto , Idoso , Agricultura , Análise de Variância , Peso Corporal , Criança , Transtornos da Nutrição Infantil/diagnóstico , Transtornos da Nutrição Infantil/etiologia , Transtornos da Nutrição Infantil/metabolismo , Pré-Escolar , Metabolismo Energético , Etiópia/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Desnutrição Proteico-Calórica/diagnóstico , Desnutrição Proteico-Calórica/etiologia , Desnutrição Proteico-Calórica/metabolismo , Fatores Socioeconômicos
14.
Eur J Clin Nutr ; 57(2): 260-5, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12571657

RESUMO

OBJECTIVE: To assess the impact of anorexia nervosa and that of nutritional rehabilitation on bone resorption. DESIGN: Cross-sectional, observational study. SETTING: Rome, Italy SUBJECTS: Twenty-eight female patients affected by anorexia nervosa (AN, BMIor=18.5 kg/m(2)) and 34 age- and sex-matched healthy controls (CO, BMI >or=18.5 kg/m(2)). Among AN patients, 16 were affected by the 'restrictive' (ANr) and 12 by the 'purging' type (ANp) of anorexia nervosa. METHOD: Body weight, height and skeletal diameters were measured on each individual. The skeletal mass (SKM) was predicted from the skeletal diameters of the elbow, wrist, knee and ankle, using the equation of Martin. Twenty-four-hour urinary excretion of pyridinium crosslinks of collagen (pyridinoline (Pyd) and deoxypyridinoline (Dpd)) and creatinine was assessed by reversed-phase HPLC with fluorimetric detection after solid-phase extraction and by the Jaffé-method with deproteinization, respectively. RESULTS: Twenty-four-hour urinary output of Pyd and Dpd was not significantly different between AN and CO when expressed in absolute values, but AN showed higher bone resorption than CO when Pyd and Dpd excretion was adjusted by either creatinine (P<0.0000) or the SKM (P<0.05). Within the AN group, urinary excretion of both cross-links was significantly and consistently higher in ANp compared with ANr (P<0.05). However, these differences disappeared when crosslink output was adjusted either by urinary creatinine or SKM. RE subjects showed no differences in bone resorption with the AN group despite weight gain, being crosslink excretion consistently elevated compared to controls (Pyd: P<0.01 by creatinine and P<0.05 by SKM; Dpd: P<0.01 by creatinine and P<0.05 by SKM). CONCLUSION: Bone resorption is elevated in anorexia nervosa and different strategies for low-weight maintenance do not seem to have a differential impact. Increased bone resorption persists in subjects with past diagnosis of anorexia nervosa despite rehabilitation lasting more than 6 months. This finding indicates that bone mass and turnover should be monitored in anorexia nervosa patients and ex-patients well beyond recovery of normal body mass. Further investigation is warranted to examine the long-term effect of such prolonged increase in bone turnover at a young age.


Assuntos
Anorexia Nervosa/fisiopatologia , Anorexia Nervosa/reabilitação , Reabsorção Óssea/etiologia , Adolescente , Adulto , Análise de Variância , Anorexia Nervosa/urina , Antropometria , Colágeno/urina , Estudos Transversais , Feminino , Humanos , Itália , Projetos Piloto , Compostos de Piridínio/urina
15.
J Biomech ; 30(2): 155-62, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9001936

RESUMO

Undecalcified samples extracted from human femoral shafts are fractured by bending and the fracture surfaces are examined with a scanning electron microscope (SEM). The investigation is performed on both dry and wet (hydrated with a saline solution) specimens. SEM micrographs show patterns in many respects similar to those observed in fractography studies of laminated fiber-reinforced synthetic composites. In particular, dry and wet samples behave like brittle and ductile matrix laminates, respectively. An analysis carried out on the basis of the mechanisms that dominate the fracture process of laminates shows that a reasonable cortical bone model is that of a laminated composite material whose matrix is composed of extracellular noncollagenous calcified proteins, and the reinforcement is constituted by the calcified collagen fiber system.


Assuntos
Fraturas do Fêmur/patologia , Fêmur/ultraestrutura , Fraturas de Estresse/patologia , Adulto , Materiais Biocompatíveis/química , Matriz Óssea/fisiologia , Matriz Óssea/ultraestrutura , Calcificação Fisiológica , Colágeno/fisiologia , Colágeno/ultraestrutura , Proteínas da Matriz Extracelular/fisiologia , Proteínas da Matriz Extracelular/ultraestrutura , Fraturas do Fêmur/fisiopatologia , Fêmur/fisiopatologia , Fraturas de Estresse/fisiopatologia , Humanos , Masculino , Microscopia Eletrônica de Varredura , Modelos Biológicos , Maleabilidade , Estresse Mecânico , Resistência à Tração
16.
J Biomech ; 28(4): 439-44, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7738052

RESUMO

A model is developed whereby the secondary osteon--the dominant microstructural component of the cortical bone tissue--is considered as an n-layered cylinder with internal stresses in linear isotropic elasticity. An exact solution is obtained for a loading condition represented by a tensile-compressive force. The lengthening, the side deformation, and the strain energy of the system are explicitly calculated. The behavior of the main elastic quantities is illustrated by graphs. In particular, the important role played by the parity of the number of lamellae is revealed.


Assuntos
Ósteon/fisiologia , Modelos Biológicos , Algoritmos , Elasticidade , Ósteon/ultraestrutura , Humanos , Distribuição de Poisson , Pressão , Estresse Mecânico , Resistência à Tração
17.
J Pediatr Endocrinol Metab ; 15(1): 27-34, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11826867

RESUMO

The aim of this study was to evaluate the effect of growth hormone (GH) treatment on bone resorption in children with GH deficiency and those with idiopathic short stature. The study population included seven children with subnormal spontaneous GH secretion and 13 children with idiopathic short stature, all of them pre-pubertal. Anthropometric measurements, free, protein-bound and total urinary pyridinoline (Pyd) and deoxypyridinoline (Dpd), serum GH, and serum immunoreactive PTH were measured at baseline and months 1, 3, 6 and 12 of GH treatment. The urinary excretion of total Pyd and Dpd, standardized by the cube of height (m3) in overnight, 24-hour urine collections was not different from age-matched healthy controls at baseline in either group of patients. During treatment with human recombinant GH, both pyridinium crosslinks increased above normal values, reaching a peak after one month in children with GH deficiency and later (after 3-6 months) in children with short stature. Free and total crosslink forms were correlated, and GH treatment did not affect the proportion of free to bound crosslinks. Serum concentrations of iPTH showed a moderate but not statistically significant increase. This study provides no evidence of reduced bone resorption in untreated GH deficiency or in idiopathic short stature. GH treatment induced a marked, but temporary, increase of bone resorption in both groups of patients.


Assuntos
Reabsorção Óssea/metabolismo , Transtornos do Crescimento/urina , Hormônio do Crescimento/efeitos adversos , Compostos de Piridínio/urina , Adolescente , Biomarcadores , Estatura/efeitos dos fármacos , Criança , Cromatografia Líquida de Alta Pressão , Colágeno/química , Colágeno/urina , Creatinina/urina , Feminino , Transtornos do Crescimento/tratamento farmacológico , Hormônio do Crescimento/uso terapêutico , Humanos , Masculino , Hormônio Paratireóideo/urina , Espectrometria de Fluorescência
18.
Arch Ital Urol Androl ; 67(1): 27-31, 1995 Feb.
Artigo em Italiano | MEDLINE | ID: mdl-7538384

RESUMO

Pressure/flow study is nowadays essential in the routine diagnostic workup of prostatic obstruction. It is the single most useful investigation showing evidence of bladder outlet obstruction. Therefore it should always be performed before any surgical treatment aimed to relieve the obstruction and it should always be referred to whenever the results of a medical treatment are judged. Lack of indication to pressure/flow study is limited to few clinical conditions such as complete urinary retention, large bladder diverticulum, high grade vesicoureteral reflux, bladder stone and/or urinary tract infection. The investigation needs much experience while is carrying out in order to avoid artifacts and then to read the pressure/flow data obtained. Results evaluation is still debatable. Nevertheless recent computerized programs allow to reduce artifacts and to obtain more reproducible and comparable data in order to make more reliable the indication to treatment or to judge its results.


Assuntos
Hiperplasia Prostática/diagnóstico , Urodinâmica , Humanos , Masculino , Modelos Biológicos , Hiperplasia Prostática/fisiopatologia , Uretra/fisiopatologia , Bexiga Urinária/fisiopatologia
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