The capacity for physical work of White miners in South Africa. 3. The maximum oxygen intakes of normal miners and miners with cardiorespiratory diseases.
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Adult↗
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[Aspects of the nitrogen cycle in calcic mull and anmorr-type humus. Mineralization of organic nitrogen and immobilization of mineral nitrogen; influence on these steps of added organic carbon, organic or mineral nitrogen, of Ca++ or K+ ions].
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In Vitro Techniques↗
Osteopontin at mineralized tissue interfaces in bone, teeth, and osseointegrated implants: ultrastructural distribution and implications for mineralized tissue formation, turnover, and repair.
Currently available data describing the gene expression and regulation, secretion, distribution, and protein chemistry of osteopontin (OPN) all are consistent with the notions of this protein functioning as an inhibitor of mineralization and/or as a mediator of cell-matrix and matrix-matrix/mineral adhesion (cohesion) during the formation, turnover, and repair of normal and pathological mineralized tissues. The properties and overall integrity of mineralized tissues are in part dictated by the nature of their interfaces--sites where organic and inorganic components of the extracellular matrix interact to provide biomechanical strength, regulate mineral ion homeostasis, and influence cellular events involved in mineralized tissue modeling, remodeling, and repair. High-resolution, colloidal-gold immunocytochemistry has been used to characterize the proteinaceous composition of these interfaces and to establish that the phosphorylated sialoprotein, OPN, is a major component found at these sites where it accumulates as a dense, planar "coating" of organic material termed either a cement line or a lamina limitans. Structural/functional features of OPN predict an ability of this protein to regulate calcification in the matrix proper of mineralized tissues and to participate, more specifically, in cell-matrix and matrix-matrix/mineral adhesion in laminae limitantes and cement lines, respectively. From the ultrastructural immunocytochemical data presented herein for OPN illustrating the cellular expression and extracellular matrix distribution of this protein, it is demonstrated that the production of OPN is one of the earliest, and latest, secretory activities of the osteoblast lineage and that this activity manifests itself morphologically as a cement line or a lamina limitans, respectively, at bone matrix interfaces. In laminae limitantes at bone surfaces, OPN appears to be involved in osteoclast adhesion and possibly haptotaxis. An OPN-containing cement line is also present at hard tissue interfaces in rat tooth, against osseointegrated titanium and hydroxyapatite implants and at the margins of surgically created bone defects--and there may influence biological adhesion in a manner similar to that proposed for normal bone. It is suggested, therefore, that in addition to its potential for influencing cell adhesion/dynamics in bones and teeth, OPN in cement lines may act as an interfacial adhesion promoter between apposing substrates, therein maintaining the overall integrity of bone during the bone remodeling sequence and "bonding" dissimilar tissues (or biocompatible materials) together in biological composites such as teeth and osseointegrated implants.
Animals↗
Prevalence of pneumoconiosis and its relationship to dust exposure in a cohort of U.S. bituminous coal miners and ex-miners.
Information on radiographic evidence of coal workers' pneumoconiosis (CWP) is presented for a group of 3,194 underground bituminous coal miners and ex-miners examined between 1985 and 1988. Prevalence of CWP was related to estimated cumulative dust exposure, age, and rank of coal. On the basis of these data, miners of medium to low rank coal, who work for 40 years at the current federal dust limit of 2 mg/m3, are predicted to have a 1.4% risk of having progressive massive fibrosis on retirement. Higher prevalences are predicted for less severe categories of CWP. Miners in high rank coal areas appear to be at greater risk than those mining medium and low rank coals. Ex-miners who said that they left mining for health-related reasons had higher levels of abnormality compared to current miners.
Adult↗
Respirable coal dust exposure and respiratory symptoms in South-African coal miners: a comparison of current and ex-miners.
OBJECTIVES: Dose-response associations between respirable dust exposure and respiratory symptoms and between symptoms and spirometry outcomes among currently employed and formerly employed South-African coal miners were investigated. METHODS: Work histories, interviews, and spirometry and cumulative exposure were assessed among 684 current and 212 ex-miners. RESULTS: Lower prevalences of symptoms were found among employed compared with ex-miners. Associations with increasing exposure for symptoms of phlegm and past history of tuberculosis were observed, whereas other symptom prevalences were higher in the higher exposure categories. Symptomatic ex-miners exhibited lower lung function compared to the nonsymptomatic. CONCLUSIONS: Compared with published data, symptoms rates were low in current miners but high in ex-miners. Although explanations could include the low prevalence of smoking and/or reporting/selection bias, a "survivor" and/or a "hire" effect is more likely, resulting in an underestimation of the dust-related effect.
Bronchitis↗
Relation between dust exposure and lung function in miners and ex-miners.
A sample of men working in the British coal industry in the 1950s has been followed up and examined 22 years later. The relations between lung function and individual cumulative exposure to respirable dust have been studied in 1867 men who were still working in the industry at the time of follow up and 2192 men who had left. Levels of forced expired volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio at follow up were found to be inversely related to exposure to respirable dust after allowing for other factors, even in men without pneumoconiosis. The magnitude of this estimated effect was equivalent to a loss of 228 ml FEV1 in response to an exposure of 300 gh/m3, a moderately high exposure for this group. Ex-miners aged under 65 had worse lung function than miners on average, suggesting that ill health had encouraged some of these men to leave the industry. Whereas a more severe response to dust exposure among ex-miners under 65 was suggested, this difference could easily have arisen by chance. The presence of symptoms of chronic bronchitis was associated with reduced levels of lung function, however, and, additionally, ex-miners under 65 with chronic bronchitis showed a more severe response of the FVC to dust exposure than miners without these symptoms. Among these ex-miners with chronic bronchitis a small group of men who had taken other jobs showed a much more severe effect of dust exposure on their lung function than the average, likely in heavily exposed men to contribute importantly to disability. Men in this group who had given up smoking showed and even more severe effect of dust exposure, equivalent to a loss of 940 ml FEV1 in response to an exposure of 300 gh/m3. These results indicate that exposure to respirable dust can occasionally cause severe respiratory impairment in the absence of progressive massive fibrosis. Dust exposure was related to a parallel reduction of FEV1 and FVC, implying that the pathology of dust induced lung damage differs form that induced by smoking. This pattern of abnormality was shown by some non-smokers, whereas smokers and ex-smokers apparently severely affected by dust showed a classic obstructive pattern of abnormality with pronounced reduction of the FEV1/FVC ratio.
Aged↗
The South Wales Miners Federation, Miners' Lung and the instrumental use of expertise, 1900-1950.
Oral history materials from the South Wales Miners' Library are used to examine the communal understandings of, collective responses to, the scourge of Miners' Lung (pneumoconiosis) in the 1920s and 1930s. Lay epidemiology in mining communities attributed an aetiological role to coaldust at a time when many experts believed miners' pulmonary disease to be bronchitic, or to be silica-induced. In their efforts to secure compensation claims for their members, union officials instrumentally used scientific expertise in a variety of forms: they contributed to epidemiological evidence; they lobbied for more government-funded research; they 'bought' experts; they duped expert witnesses; and they made sophisticated instrumental appeals to the supposed independence of favorable expert judgements. Eventually, miners' situated' 'local knowledge' became scientific orthodoxy, a success story which may be associated with the class-conscious miners' 'bump of irreverence' about expert knowledge, and with the divided character of the expert core-set, sections of which were receptive to miners' 'local knowledge' claims.
Attitude to Health↗
Heterotopic implantation of mouse bone-marrow cells: an in vivo model allowing analysis of mineral phases during mineralization processes.
Heterotopic calcification induced after implantation of bone-marrow cells under the murine kidney capsule was used to study the mineral phases occurring during the mineralization process. Ossicles were found to contain numerous osteoblastic cells that produced an organic matrix closely associated with active hematopoietic tissue. During implantation of bone marrow, needle-shaped microcrystals were progressively deposited on collagen fibers. The mineral formed in the heterotopic calcification consisted mainly of calcium phosphate. The distribution and density of the microcrystals were heterogeneous after 6 weeks of implantation but became homogeneous and well-crystallized after 10 weeks. The Fourier transform infrared microspectroscopy provided important spatial data on the nature of the mineral formed and the changes in the mineral environment. Similarities were noted between young bone (bone callus) and 6-week heterotopic ossicles, and between adult bone and 10- or 12-week heterotopic ossicles. The study demonstrated that murine heterotopic calcification under the renal capsule can be a very useful model for studying bone apatite formation during the mineralization process.
Animals↗
Soft tissue composition, axial bone mineral density, and grip strength in postmenopausal Turkish women with early rheumatoid arthritis: Is lean body mass a predictor of bone mineral density in rheumatoid arthritis?
OBJECTIVE: To study bone mineral density and body composition in patients with early rheumatoid arthritis to determine the relationship of lean mass, fat mass and hand grip strength to bone mineral density. METHODS: Fifty-one female patients who fulfilled the American College of Rheumatology (ACR) for RA were recruited. Fifty-one (51) female RA patients, age matched female control subjects and 53 osteoporotic patients (WHO criteria) were included in the study. All subjects were at postmenopausal period. Early RA is defined as the disease duration <10 years. Whole body composition and BMD were estimated by DEXA (Norland XR-46). Hand grip strength was measured by JAMAR hand dynamometer. Body mass index (BMI) and anthropometric measures (skinfold thickness and waist-hip ratio) were also assessed. RESULTS: The mean age of patients and controls was 55.4 +/- 9.5, 56.9 +/- 7.4, and 55.2 +/- 7.6, respectively. There was no statistically significant difference in age, BMI, and years since menopause between RA patients, OP patients, and controls (p < 0.05). Bone mineral density of lumbar and femoral neck regions, total bone mineral density, and bone mineral content in RA patients were significantly lower than in controls but not in osteoporotic patients. Lean body mass was also significantly lower in RA patients than controls but not in osteoporotic patients. However, hand grip strength was significantly lower in RA patients than in osteoporotic patients and controls (p < 0.05). Total lean mass was correlated with body mass index, waist-hip ratio, femoral neck BMD, and total bone mineral content, total BMD in RA patients (p < 0.05). Grip strength was correlated with duration of disease (RA) and age negatively, and also correlated with total BMD in RA patients. CONCLUSION: These results indicate that lean mass was associated with BMD. To preserve BMD, maintaining or increasing lean mass would appear to be an appropriate strategy for avoiding hip fracture and its complications.
Absorptiometry, Photon↗
[The early changes in bone mineral metabolism due to radiation--measurement of bone mineral density in lumbar vertebra by quantitative computed tomography].
Osteosclerosis, osteonecrosis and compression fracture are commonly observed several years after radiation. Since lumbago usually occurs several months after radiation, the possibility that bone mineral metabolism is disturbed during and immediately after radiation cannot be ruled out. However, there have been no reports concerning early changes in bone mineral metabolism due to radiation. The bone mineral density was measured by QCT (Quantitative Computed Tomography) in 30 normal non-radiated cases and 14 radiated cases to investigate the changes in bone mineral metabolism due to radiation. The bone mineral density (QCT-Value: QCT-V) in the 3rd lumbar vertebra (L3) of normal non-radiated subjects decreased linearly with age (Y = 291.114447-3.01473X). The QCT-V of the 5th lumbar vertebra (L5) of normal cases also decreased linearly with age (Y = 309.641397-3.03986X), resembling that of L3. The ratio of the QCT-V of L5 to L3 (L5/L3, expressed as a percentage) definitely increased with age (Y = 86.5657441 + 0.58885064X). In radiated cases, the QCT-V of L3 in the non-radiated field did not change appreciably. The QCT-V of L5 in the radiated field was decreased from 20GY and reached 53.08 +/- 17.37% of the pre-radiation value after 50GY. The L5/L3 ratio was also decreased from 20GY and reached 55.47 +/- 15.32% of the pre-radiation value after 50GY. It becomes apparent that the QCT-V of the radiated lumbar vertebra is decreased during radiation. It is suggested that bone mineral metabolism may be disturbed in the early phase of radiation.
Bone Density↗
[The bone mineral density change with aging of women and usefulness of single energy X-ray absorptiometry for measurement of bone mineral content].
The calcaneus bone mineral density of 473 women was measured by single photon absorptiometry (SPA) and the vertebrae bone mineral density of 198 women was measured by dual energy X-ray absorptiometry (DEXA). The calcaneus bone mineral density of women starts decreasing at age 30, and the rate of decrease accelerates after the age of 50. The vertebrae bone mineral density starts decreasing at the age of 35, and a conspicuous decrease can be seen after the age of 50 as well. Because bone deterioration of Japanese women is thought to start earlier than in Europeans and Americans, the necessity of osteoporosis screening before menopause was suggested. A high positive correlation (r = 0.804) between calcaneus bone mineral density and vertebrae bone mineral density was found, and a high degree of precision of SXA was shown.
Absorptiometry, Photon↗
[Legal requirements, quality criteria, therapeutic interest and dietetics of mineral waters: study of the case of the natural mineral water of Evian].
The considerable increase in mineral water sales as a daily drink reflects more or less the continued confidence in spa treatments, and this has caused the Public Authorities to set up very strict regulations in this field. We explain the main provisions of these regulations, compare mineral water with ordinary drinking water and complete this report with a study on the representative case of Evian Mineral water since it is the most exported water in the world. We emphasize the key points regarding the origin of the water which must be very well protected, its mineralization leading to its part played in dietetics and daily consumption, its use in spas and the research on its therapeutic effects, its bottling and the controls enabling its original high quality to be maintained. The conclusion reviews the motivations for the mineral water consumer: taste, quality, favorable effects on health. These motivations linked together have a varying importance according to the persons or situations involved. They result in precise requirements to be met by the producing companies in three fields: quality, advertising, credibility and scientific research.
Balneology↗
Mineralized collagen fibrils: a mechanical model with a staggered arrangement of mineral particles.
Both elastic modulus and fracture stress are known to increase with the amount of mineral deposited within collagen fibrils. Current mechanical models of mineralized fibrils, where mineral platelets are arranged in parallel arrays, reproduce the first effect but fail to predict an increase in fracture stress. Here, we propose a model with a staggered array of platelets that is in better agreement with results on molecular packing in collagen fibrils and that accounts for an increase of both elastic modulus and fracture stress with the amount of mineral in the fibril. Finally, we explore the dependence of the mechanical properties within the model, when the degree of mineralization and the thickness of the platelets as well as their distance varies.
Animals↗
[Effect of the manganese content in laying hen feed with different Ca and mineral levels on the egg shell quality and bone mineralization of hens].
Four experiments with 270, 44, 432 and 66800 Leghorn hens were carried out to investigate the influence of various Mn additions to diets differed in mineral or Ca contents on egg shell quality. The addition of 300 mg Mn/kg diet improved significantly egg shell breaking strength by 4 N over one year. The supply of 50-500 mg Mn/kg diet for 10-24 weeks of the second half of laying year did not influence the egg shell quality. Addition of mineral mixture or Ca grit to layer rations with adequate or higher Mn levels did not influence egg shell strength. High mineral content in a low manganese diet increased number of cracks by 3%. Strength, weight and ash content of tibia were significantly reduced by feeding a low mineral level. Addition of 50-150 mg Mn per kg low mineral diet normalized partially tibia stability in young hens. It was concluded that supplied dietary Manganese influences calcification positively only in young hens. High levels of Ca did not influence the effects of Mn. 50 mg Mn per kg layers mixture have been considered as an essential supply.
Animal Feed↗
The effect of microbial phytase in a pearl millet-soybean meal diet on apparent digestibility and retention of nutrients, serum mineral concentration, and bone mineral density of nursery pigs.
Eighteen gilts (initial BW of 10.9 kg; age 4 wk) were used in a 35-d experiment to study the effects of adding microbial phytase to a pearl millet-soybean meal-based diet on growth, apparent digestibility and retention of nutrients, and bone mineral status. The dietary treatments were arranged in a 2 x 3 factorial with two levels of P (.58%, low-P or .95%, adequate-P) and three levels of microbial phytase (0, 700, or 1,000 units/kg of diet). Phosphorus, Ca, and N balance were determined from d 32 to 35. Blood samples were collected on d 0 and 35 for serum mineral analysis. Global bone mineral content (GBMC) and global bone mineral density (GBMD) were determined on d 0 and 35 using dual-energy x-ray absorptiometry (DXA). A microbial phytase level x P level interaction was observed for final BW, ADG, gain:feed (P < .001), and serum P concentration (P < .003). Phytase supplementation of the low-P diets increased final BW, ADG, gain: feed, and serum inorganic P concentration but did not improve growth or serum inorganic P concentration in pigs fed the adequate-P diets. The addition of microbial phytase to the low-P and adequate-P diets reduced fecal P (P < .01), fecal N (P < .05), increased P absorption and retention (P < .01), and increased N absorption (P < .05). Pigs fed the adequate-P diets absorbed more P (P < .01) but excreted more P (P < .01) in the feces. Phytase tended to increase Ca (P < .07) and N (P < .10) retention, apparent threonine digestibility (P < .06), and serum Zn concentration (P < .09). Phytase increased GBMC and GBMD (P < .04). Phosphorus also increased GBMC and GBMD (P < .007 and P < .002, respectively). These results show that supplemental microbial phytase in pearl millet-soybean meal diets increased P availability, decreased the amount of P excreted in feces, and increased bone mineralization in nursery pigs.
6-Phytase↗
Mineral content of milk, colostrum, and serum as affected by physiological state and mineral supplementation.
A 22-mo experiment was conducted to determine effects of mineral supplementation of cows on mineral elements in milk, colostrum, and blood serum. Purebred Brahman beef cows grazing pastures grown on sandy and well-drained soils were allotted to three treatments of 12 cows each as follows: control, a complete commercial mineral mixture, control plus dietary and injected Se, and control plus fortified mineral mixture. Milk and serum were analyzed for minerals 2 consecutive yr at parturition and 3 mo postpartum. Mean cow serum, Ca, Mg, P, and packed cell volume values were higher at parturition than 3 mo later, whereas serum Cu was highest at 3 mo. Mean serum concentrations were affected by year with higher Ca and hemoglobin and lower Cu concentrations in 1982 than in 1981. Increasing dietary Se resulted in higher serum Se. Colostrum was higher in Mg, P, Cu, Fe, Se, and Zn than milk, whereas milk was higher than colostrum in Mn. Means for treatment X time showed cows fed dietary and dietary plus injected Se and vitamin E had more Se in milk than milk from cows fed no supplemental Se.
Animals↗
Mineral balance and urinary and fecal mineral excretion profile of broilers housed in thermoneutral and heat-distressed environments.
Two experiments were conducted utilizing 4- to 7-wk posthatching Vantress x Arbor Acres male broilers to evaluate heat distress effects on mineral balance partitioned into urinary and fecal loss. In the first study, 8 colostomized and 14 intact birds were allotted to two environmental chambers maintained at either a thermoneutral temperature (24 C) or a cycling temperature heat distress (24 to 35 C) in a switch-back design. Birds were precision-fed 2% of body weight thrice daily to equalize consumption prior to and over each 48-h experimental period. Feces and urine for colostomized birds and total excrement for intact birds were collected and analyzed for mineral content. Averaging across surgical classification, heat distress increased (P less than .05) excretion of K, P, S, Mg, Cu, Mo, and Zn. Despite little heat distress effect on urine production, minerals disproportionately excreted in urine included K, Mg, P, and S; Cu and Mg were lost primarily in feces. In the second study 42 colostomized birds were used to expand the urinary excretion data with the period of heat distress held at 35 C for 36 h. Heat distress increased (P less than .05) urine output from 52.3 +/- 5.3 to 109.9 +/- 4.5 mL/12 h and also increased total urinary K, P, S, Na, Mg, Ca, and Mn excretion. The present data provide evidence that heat distress adversely impacts bird mineral balance and that the excretion route for this effect varies with the specific mineral and possibly, heat distress severity.
Animals↗
[Effect of fluorine in drinking water of varying hardness on protein-mineral metabolism of mineralized tissues of rats maintained on a sugar diet].
Variations of mineral and protein metabolism in calcified tissues were studied using 32P, 45Ca and 35S methionine in the rats on sugar diet and water of different hardness with F and without it. Hard drinking water without F like soft water and water of medium hardness with F affect metabolism in mineralized tissues preventing the development of carious process. Incorporation of 32P and 45Ca to mineralized tissues, specific radioactivity of 32P and 35S methionine of tooth and bone proteins are lower in rats which drank soft water without F. These parameters increase in rats which received hard water without F almost to the level of animals which received water with F. Ways of the effect of Ca2+ Mg2+ and F on protein and mineral metabolism of calcified tissues of rats on sugar diet (including proteins (osteo-induced, etc., which initiate mineralization) and enzymes are considered.
Animals↗