More Bone with Less Minerals? The Effects of Dietary Phosphorus on the Post-Cranial Skeleton in Zebrafish.

Dietary phosphorus (P) is essential for bone mineralisation in vertebrates. P deficiency can cause growth retardation, osteomalacia and bone deformities, both in teleosts and in mammals. Conversely, excess P supply can trigger soft tissue calcification and bone hypermineralisation. This study uses a wide range of complementary techniques (X-rays, histology, TEM, synchrotron X-ray tomographic microscopy, nanoindentation) to describe in detail the effects of dietary P on the zebrafish skeleton, after two months of administering three different diets: 0.5% (low P, LP), 1.0% (regular P, RP), and 1.5% (high P, HP) total P content. LP zebrafish display growth retardation and hypomineralised bones, albeit without deformities. LP zebrafish increase production of non-mineralised bone matrix, and osteoblasts have enlarged endoplasmic reticulum cisternae, indicative for increased collagen synthesis. The HP diet promotes growth, high mineralisation, and stiffness but causes vertebral centra fusions. Structure and arrangement of bone matrix collagen fibres are not influenced by dietary P in all three groups. In conclusion, low dietary P content stimulates the formation of non-mineralised bone without inducing malformations. This indicates that bone formation and mineralisation are uncoupled. In contrast, high dietary P content promotes mineralisation and vertebral body fusions. This new zebrafish model is a useful tool to understand the mechanisms underlying osteomalacia and abnormal mineralisation, due to underlying variations in dietary P levels.

Intakes of Calcium and Phosphorus and Calculated Calcium-to-Phosphorus Ratios of Older Adults: NHANES 2005-2006 Data.

BACKGROUND: High intakes of dietary phosphorus (P), relative to calcium (Ca) intake, are associated with a lower calcium:phosphorus ratio (Ca:P) ratio which potentially has adverse health effects, including arterial calcification, bone loss, and death. A substantial percentage of older adults (50 to 70 and 71 plus years) who have a higher risk of fracture rate than younger adults typically have low intakes of dietary Ca that are dominated by higher intakes of dietary P from natural and fortified foods, and lower Ca:P ratios than desirable. OBJECTIVE: This investigation was undertaken to examine Ca and P intakes and the resulting Ca:P ratios (by mass) across gender and older adult age groups, using data from the National Health and Nutrition Examination Survey (NHANES) 2005-2006. DESIGN: NHANES data are based on a cross-sectional sample of the non-institutionalized United States (US) population within various regions. This sample is selected to be representative of the entire US population at all ages. National Cancer Institute (NCI) methods and SAS survey procedures were used for analyses. Ca:P ratios were calculated using total Ca from both foods and supplements, whereas P intakes were calculated from food composition values and supplements. The amounts of P additives in processed foods are not available. RESULTS: Mean Ca and P intakes demonstrated lower intakes of Ca and higher intakes of P compared to current Recommended Dietary Allowances (RDAs). The Ca:P ratios in older male and female adults were influenced by both low-Ca and high-P dietary consumption patterns. CONCLUSIONS: Both low total Ca intakes and high P amounts contribute to lower Ca:P ratios, i.e., ~0.7:1.0, in the consumption patterns of older adults than is recommended by the RDAs, i.e., ~1.5:1.0. Whether Ca:P ratios lower than recommended contribute to increased risk of bone loss, arterial calcification, and all-cause mortality cannot be inferred from these data. Additional amounts of chemical P additives in the food supply may actually reduce even further the Ca:P ratios of older adults of both genders, but, without P additive data from the food industry, calculation of more precise ratios from NHANES 2005-2006 data is not possible.

Uma análise da prevenção do câncer de mama no Brasil / An analysis of breast cancer prevention in Brazil

ResumoA presente pesquisa se propõe a estudar as inter-relações entre a prevenção do câncer de mama e os fatores socioeconômicos, demográficos, comportamentais, regionais e de saúde na determinação da frequência temporal à busca por prevenção via realização de mamografias e exames de mama no Brasil. A partir das informações do suplemento de saúde da Pesquisa Nacional por Amostra de Domicílios, de 2008, foi construída uma amostra que contempla apenas mulheres com mais de 40 anos de idade. Para o atendimento do objetivo proposto, faz-se uso da estimação do modelo logit, ordenado de chances proporcionais parciais, que indicaram como principais resultados: i) melhores condições socioeconômicas, residir nas regiões mais desenvolvidas do país, uma composição familiar que inclua filhos, apresentar uma boa autoavaliação da própria saúde e já ter sido diagnosticada com algum tipo de câncer, desenham o perfil da mulher que mais se previne contra o câncer de mama, tanto em relação à procura por mamografia, como a uma maior demanda por exame de mama realizado por médico ou enfermeiro e; ii) os resultados apontam ainda para o fato de que grande parte das entrevistadas realizaram os exames em questão há pelo menos um ano, ou nunca passaram por tais procedimentos.

AbstractThis research sets out to study the interrelationship between breast cancer prevention and the socioeconomic, demographic, behavioral, regional and health factors in determining the temporal frequency of tests for prevention by performing mammograms and breast exams in Brazil. Based on the information of the health supplement of the National Sampling Survey of Domiciles of 2008, a sample that includes only women over age 40 was created. To achieve the desired goal, the estimate of the ordered logit model is used to establish partial proportional odds, which revealed the main results as follows. Women with a good socioeconomic status, living in the more developed regions of the country, family structure including children, making a good self-assessment of health and having been diagnosed with some type of cancer in the past. This is the profile of women who are best at preventing breast cancer, both in relation to the demand for mammograms and to a greater demand for breast exam performed by a doctor or a nurse. The results also point to the fact that the majority of those interviewed had either had the tests in question within the previous year, or had never been exposed to such procedures.

Deficiências minerais em vacas em lactação da bacia leiteira do município de Rondon do Pará, estado do Pará / Mineral deficiencies in lactating cows from the dairy basin of Rondon do Pará, Brazil

Realizou-se um estudo das deficiências minerais em vacas em lactação de rebanhos leiteiros pertencentes a 13 propriedades da bacia leiteira do município de Rondon do Pará, estado do Pará. Foram determinados os níveis de fósforo (P) no osso, e os níveis de cobre (Cu), cobalto (Co), selênio (Se) e zinco (Zn) no fígado de 47 vacas leiteiras no 2º terço da lactação. Estas amostras foram coletadas por meio de biópsias realizadas no terço superior da 12a costela do lado direito e no bordo caudal do lobo caudado do fígado, respectivamente. Os rebanhos eram formados por animais mestiços (Holandes x Zebu), mantidos em sistema de produção extensivo em pastos de Brachiaria brizantha cv Marandu e recebiam suplementação mineral. A mistura mineral em 12 propriedades era do tipo comercial, dita "completa", acrescida de quantidades de NaCl acima do recomendado pelos fabricantes em dez propriedades. Em sete propriedades as misturas minerais eram fornecidas em cochos sem cobertura e em oito, o fornecimento da mistura mineral não era realizado diariamente. Em 11 propriedades, havia históricos clínicos condizentes com deficiências minerais nos rebanhos. Nessas fazendas a retenção de placenta e a osteofagia foram as alterações mais relatadas. Após as análises minerais observou-se deficiência de P em cinco propriedades, de Co em três propriedades, de Se em nove propriedades e de Zn em dez propriedades. Conclui-se que ocorre a deficiência de P, Co, Se e Zn; a suplementação mineral realizada na maioria das propriedades não atendeu as exigências diárias de P, Se e Co, baseadas no consumo estimado de 30 g de NaCl/animal/dia; os cochos pouco adequados ou inadequados para a suplementação, assim como o fornecimento inconstante das misturas minerais possivelmente contribuíram para a deficiência de um ou mais minerais.

A study of mineral deficiencies was performed in lactating cows from dairy herds belonging to 13 farms of Rondon do Pará, state of Pará, Brazil. We determined the levels of phosphorus (P) in the bone and levels of copper (Cu), cobalt (Co), selenium (Se) and zinc (Zn) in the liver of 47 dairy cows in lactation 2. The samples were collected by means of biopsies taken on the top third of the 12th rib of the right side and the caudal edge of the caudate liver lobe, respectively. The herds were composed of crossbred (Holstein x Zebu) cattle, kept in extensive production system on Brachiaria brizantha cv. Marandu pasture and received mineral supplementation. The mineral mixture on 12 farms were commercial type, called "full" and the owners added a quantity of salt above the manufacturer's recommendations on ten farms. The mineral mixtures were provided in troughs without covering on seven farms and on other eight, providing of the mineral mix was not performed daily. On 11 farms there were clinical histories consistent with mineral deficiencies in livestock, and placenta retention and osteophagia were the most frequently reported ones. The results of chemical analysis showed deficiency of P on five farms, of Co on three farms, of Se on nine farms and of Zn on ten farms. It is concluded that the mineral supplementation performed on the farms do not supply the daily demands of P, Se and Co, based on the estimated daily consumption of 30g of NaCl per animal; the little adequate or inadequate troughs for proper supplementation, as well as inconstant supply of mineral mixtures contribute to the deficiency of one or more minerals.

Experimental infection with the Toxoplasma gondii ME-49 strain in the Brazilian BR-1 mini pig is a suitable animal model for human toxoplasmosis

Toxoplasma gondii causes toxoplasmosis, a worldwide disease. Experimentation with pigs is necessary for the development of new therapeutic approaches to human diseases. BR-1 mini pigs were intramuscularly infected with T. gondii with tachyzoites (RH strain) or orally infected with cysts (ME-49 strain). Haematology and serum biochemistry were analysed and buffy coat cells were inoculated in mice to determine tachyzoite circulation. No alterations were observed in erythrocyte and platelet values; however, band neutrophils increased seven days after infection with ME-49. Serology of the mice inoculated with pig blood leucocytes revealed circulating ME-49 or RH strain tachyzoites in the pigs' peripheral blood at two and seven or nine days post-infection. The tachyzoites were also directly observed in blood smears from the infected pigs outside and inside leucocytes for longer periods. Alanine-aminotransferase was high at days 21 and 32 in the RH infected pigs. After 90 days, the pigs were euthanised and their tissue samples were processed and inoculated into mice. The mice serology revealed the presence of parasites in the hearts, ileums and mesenteric lymph nodes of the pigs. Additionally, cysts in the mice were only observed after pig heart tissue inoculation. The infected pigs presented similar human outcomes with relatively low pathogenicity and the BR-1 mini pig model infected with ME-49 is suitable to monitor experimental toxoplasmosis.

Níveis de fósforo disponível em dietas para suínos dos 15 aos 30kg / Available phosphorus levels in diets for pigs from 15 to 30kg

Avaliou-se a suplementação de dietas com fósforo disponível (Pd) para suínos selecionados para deposição de carne, utilizando-se 100 leitões com média de peso inicial de 15,03±0,33kg, distribuídos em delineamento de blocos ao acaso, com cinco tratamentos, cinco repetições e quatro animais por unidade experimental. Os tratamentos foram dieta basal sem suplementação de fosfato bicálcico e outras quatro dietas obtidas pela suplementação da dieta basal com fosfato bicálcico, resultando em cinco concentrações de Pd, 0,106; 0,221; 0,310; 0,406; e 0,493%. As porcentagens de Pd influenciaram o consumo diário de ração, que aumentou de forma linear. O ganho de peso diário aumentou e a conversão alimentar melhorou de forma quadrática até a suplementação máxima de 0,450 e 0,390% de Pd, respectivamente. Não houve efeito da suplementação das dietas sobre a resistência óssea. As porcentagens de Pd influenciaram de forma quadrática os teores de cálcio e de fósforo nos ossos, que aumentaram até a adição máxima de 0,388 e 0,369% de Pd, respectivamente. Não houve efeito da porcentagem de Pd sobre o teor de cinza óssea. Suínos dos 15 aos 30kg exigem maior concentração de Pd para máximo ganho de peso (0,450% ou 5,33g/dia) e melhor conversão alimentar (0,390% ou 4,52g/dia) em relação às recomendações atuais.

The supplementation of diets with available phosphorus (aP) for pigs selected for meat deposition was evaluated, using 100 commercial hybrid piglets, 50 castrated males and 50 females, with average initial weight of 15.03±0.33kg allotted in a randomized block design with five treatments, five replicates, and four pigs, 2 males and 2 females per experimental unit. The treatments were a basal diet and other four diets obtained through basal diet supplementation with dicalcium phosphate to obtain five aP concentrations, 0.106, 0.221, 0.310, 0,406, and 0.493%. The percentages of aP influenced daily feed intake, which increased linearly. Daily weight gain increased and feed conversion improved quadratically up to 0.450 and 0.390% maximum responses. There was no effect of diet supplementation on bone strength. The percentages of aP influenced the calcium and phosphorus contents in the bones, which increased quadratically up to 0.388 and 0.369% maximum responses, respectively. There was no effect of aP percentage in the bone ashe content. Pigs from 15 to 30kg require greater amount of aP in the diet for maximal weight gain (0.450% or 5.33g/d) and greatest feed conversion (0.390% or 4.52g/d) compared to current requirements.

Evaluación de diez especies de pescado para su inclusión como parte de la dieta renal, por su contenido de proteína, fósforo y ácidos grasos

Debido a la complejidad de la enfermedad renal, su tratamiento nutrimental es complicado y muchos alimentos se encuentran restringidos, entre ellos el pescado, por su contenido de fósforo. El objetivo del presente estudio fue cuantificar en el filete de diez especies de pescado, de consumo cotidiano en México: (Cyprinus carpio carpio, Ophichthus rex, Symphurus elongatus, Eucinostomus entomelas, Chirostoma patzcuaro, Bairdiella chrysoura, Salmo salar, Oreochromis urolepis hornorum, Sphyraena guachancho, Istiophorus albicans), el contenido de fósforo (P), proteína (Pr), colesterol, sodio, potasio, vitaminas D3 y E y ácidos grasos n-3 (EPA+DHA); para identificar, aquellos pescados que podrían ser incluidos en la dieta renal. Los análisis se realizaron de acuerdo a las técnicas del AOAC. Con los resultados se calcularon las relaciones entre los nutrimentos benéficos (EPA+DHA, vitaminas) y limitantes (Pr, P, colesterol). Los valores de proteína variaron entre 16.5 y 33.5g/100g de filete; el pescado con mayor contenido de fósforo fue Salmo salar y con menor Symphurus elongatus. La cantidad de EPA+DHA varió desde 79.64mg/100g hasta 1,381.53mg/100g. Tomando en cuenta la relación P/g de Pr recomendada para pacientes renales, todas las especies analizadas exceptuando Salmo salar, Ophichthus rex y Istiophorus albicans pueden ser incluidas en la dieta dependiendo de la etapa de la enfermedad. Considerando la relación entre P/EPA+DHA, las especies recomendadas para el paciente renal son Symphurus elongatus, Bairdiella chrysoura, y Sphyraena guachancho.

Evaluation of ten fish species to be included as part of renal diet, due to their protein, phosphorus and fatty acids content. Because renal disease is highly complex, its nutritional treatment is complicated and many foods are restricted, including fish because its phosphorus content. The aim of the present study was to analyze ten fillet fish species, commonly consumed in Mexico (Cyprinus carpio carpio, Ophichthus rex, Symphurus elongatus, Eucinostomus entomelas, Chirostoma patzcuaro, Bairdiella chrysoura, Salmo salar, Oreochromis urolepis hornorum, Sphyraena guachancho, Istiophorus albicans), to determine their phosphorus (P), protein (Pr), cholesterol, sodium, potassium, vitamins D3 and E, and n-3 PUFA (EPA+DHA) according to the AOAC techniques, in order to identify which species could be included in renal diet; particularly because of their risk:benefit relations (calculated with those results). Protein values ranged from 16.5 to 33.5g/100g of fillet; the specie with the highest phosphorus contest was Salmo salar, and with the lowest, Symphurus elongatus. EPA+DHA quantity ranged from 79.64mg/100g to 1,381.53mg/100g. Considering de P/Pr relation recommended to renal patients, all analyzed species (except Salmo salar, Ophichthus rex and Istiophorus albicans) could be included in their diet. As for the P/EPA+DHA relation, the species most recommended to renal patients are Symphurus elongatus, Bairdiella chrysoura and Sphyraena guachancho.

Impact of a high-phosphorus diet on the sonographic and CT appearance of kidneys in degus, and possible concurrence with dental problems.

The main aim of this study was to investigate the impact of pelleted diet of different mineral composition on the sonographic and CT appearance of kidneys in degus (Octodon degus). A total of 35 animals were randomly divided into five groups, fed diets containing different calcium and phosphorus contents (13.5 g/kg calcium and 6.3 g/kg phosphorus, or 9.1 g/kg calcium and 9.5 g/kg phosphorus) and given different amounts of exposure to UV light. Endoscopic examination of the oral cavity as well as renal ultrasonography and CT was performed four times at four-month intervals throughout the study. After 14 months of feeding an experimental diet, all degus were euthanased and subsequently all kidneys were collected for histopathological examination. Animals fed a diet with high dietary phosphate and improper calcium to phosphorus ratio showed severe nephrocalcinosis. Ultrasonographic and CT kidney abnormalities presented as hyperechogenicity and hyperdensity (interpreted as nephrocalcinosis), respectively. The most striking changes were seen at the corticomedullary zone. Ultrasonography and CT correlated in all cases with histopathological findings. Dental disease developed quickly in groups fed diets with an improper calcium and phosphorus content, with obvious apical and coronal elongation of all the teeth. A possible influence of UV light access could not be proved in this study.

[Evaluation of ten fish species to be included as part of renal diet, due to their protein, phosphorus and fatty acids content]. / Evaluación de diez especies de pescado para su inclusión como parte de la dieta renal, por su contenido de proteína, fósforo y ácidos grasos.

Because renal disease is highly complex, its nutritional treatment is complicated and many foods are restricted, including fish because its phosphorus content. The aim of the present study was to analyze ten fillet fish species, commonly consumed in Mexico (Cyprinus carpio carpio, Ophichthus rex, Symphurus elongatus, Eucinostomus entomelas, Chirostoma patzcuaro, Bairdiella chrysoura, Salmo salar Oreochromis urolepis hornorum, Sphyraena guachancho, Istiophorus albicans), to determine their phosphorus (P), protein (Pr), cholesterol, sodium, potassium, vitamins D3 and E, and n-3 PUFA (EPA+DHA) according to the AOAC techniques, in order to identify which species could be included in renal diet; particularly because of their risk:benefit relations (calculated with those results). Protein values ranged from 16.5 to 33.5g/100 g of fillet; the specie with the highest phosphorus contest was Salmo salar, and with the lowest, Symphurus elongatus. EPA+DHA quantity ranged from 79.64 mg/100 g to 1,381.53 mg/100 g. Considering de P/Pr relation recommended to renal patients, all analyzed species (except Salmo salar, Ophichthus rex and Istiophorus albicans) could be included in their diet. As for the P/EPA+DHA relation, the species most recommended to renal patients are Symphurus elongatus, Bairdiella chrysoura and Sphyraena guachancho.

Modelos matemáticos no estudo do fluxo biológico de fósforo em ovinos que receberam na dieta níveis crescentes do mineral / Mathematical models to study the biological phosphorus flow in sheep fed increasing levels of mineral

Dois modelos compartimentais foram aplicados e comparados para avaliar o fluxo biológico de fósforo em ovinos que receberam dietas com níveis crescentes do mineral - 0, 2, 4 e 6g por dia. Foram utilizados 24 machos, da raça Santa Inês, com média de peso de 33,6kg. Foi utilizado fosfato bicálcico como fonte de fósforo e 32P como traçador. Avaliou-se o fluxo de fósforo entre os compartimentos: trato gastrintestinal, sangue, ossos e tecidos moles, além da ingestão, excreção e balanço do mineral. O incremento na ingestão de P aumentou a perda fecal do mineral. O fluxo de fósforo entre o trato gastrintestinal e o sangue e o fluxo contrário foram influenciados de forma quadrática pelo incremento na ingestão, diminuindo após a ingestão de 5,5g/dia, sem diferença entre os modelos avaliados. Os modelos estudados mostraram diferenças em relação ao fluxo entre sangue, ossos e tecidos moles, sem efeito dos tratamentos sobre o balanço geral do mineral, porém os níveis de ingestão praticados interferiram no fluxo biológico do fósforo. A disponibilidade biológica do fósforo ingerido diminuiu quando a ingestão superou a necessidade do animal, o que aumentou as excreções no ambiente. A quantificação do fluxo biológico de fósforo diferiu quando aplicados os modelos estudados em decorrência da sua estrutura.

Two compartimental models were applied and compared to evaluate the biological flow of P in lambs fed diets containing increasing levels of P (0, 2, 4 and 6g per day). Twenty four Santa Inês lambs with liveweight of 33.6kg were used. Dicalcium phosphate was used as P source and 32P as a tracer. P flow between compartments (gastrointestinal tract, blood, bones and soft tissues), ingestion, excretion and the mineral balance were evaluated. The increase in P intake increased fecal P loss. P flow from gastrointestinal tract to blood stream and opposite flow were affected quadratically by increased P intake, decreasing after the ingestion of 5.5g/day, without a difference among models. The models studied showed differences regarding the P flow between blood, bone and soft tissues, however, the P balance was not affected by the treatments. The increased P levels interfered with the biological P flow in sheep. The bioavailability of P diet decreases when intake exceeds the animal requirement, increasing losses to the environment. The quantification of biological P flow was different between models due to the structure of each one.

[Relationship of deoxypyridinole excretion with bone density, serum estradiol and years of postmenopause in Mexican postmenopausic women]. / Excreción urinaria de deoxipiridinolina y su relación con la densidad mineral ósea, el estradiol sérico y los años de postmenopausia en mujeres Mexicanas.

Deoxypyridinoline is one of the metabolites produced during bone resorption. Deoxypyridinoline excretion, unlike other markers, is not affected by diet, or the activity level of other tissues. In postmenopausic women, increased excretion of deoxypyridinoline has been associated with increased bone mass loss. The objective of this study was to determine the association of deoxypyridinoline excretion in postmenopausic Mexican women with anthropometric factors, bone mass density, calcium and phosphorous intakes, post menopause years and serum levels of estradiol. The concentration of deoxypyridinoline in 24 h urine was determined utilizing an ELISA technique. An average of 7,27 +/- 5,31 nM Dpd/mM creatinine was found. A negative correlation between deoxypyridinoline and serum estradiol levels (r = -0.37, p = 0.01) was found. Post menopausic years correlated positively (r = .35, p = 0.02) with Dpd. No significant correlation between deoxypyridinoline and anthropometric data, bone mass density, calcium and phosphorous intakes was found. In conclusion, 30% of the subjects of this study had elevated levels of deoxypyridinoline excretion and taking into consideration the negative correlation observed with serum estradiol, this segment of the population could be at risk for accelerated bone loss. Hormone replacement is important for post menopausic women to prevent increased bone loss.

The absorption of iron, calcium, phosphorus, magnesium, copper and zinc in the jejunum-ileum of control and iron-deficient rats.

The effects of iron deficiency on the absorption of different dietary sources of iron were studied, together with the interactions between iron, calcium, phosphorus, magnesium, copper and zinc in the jejunum-ileum of control and iron-deficient rats. In this study, three perfusion solutions containing different iron sources: ferric citrate, haemoglobin, and equal parts of ferric citrate and haemoglobin were used. In addition, the same perfusion solutions were used with and without 2,4-dinitrophenol, an inhibitor of oxidative phosphorylation. Iron absorption in anaemic rats was greater than in the controls, except after perfusion with solutions containing haemoglobin. The absorption of calcium, copper and zinc in iron-deficient animals was not significantly affected, while the absorption of phosphorus and magnesium increased, with respect to animals in the control group. After perfusion with solutions containing haemoglobin, the absorption values of calcium, copper and zinc were lower than after ferric citrate in both groups (control and iron-deficient rats).