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Fourier transform infrared characterization of mineral phases formed during induction of mineralization by collagenase-released matrix vesicles in vitro.

Fourier transform infrared spectroscopy (FTIR) was used to characterize the organic and mineral phases present during the induction of mineral formation by collagenase-released matrix vesicles (CRMV) during incubation in a synthetic cartilage lymph in vitro. CRMV mineralization, which occurs in the absence of alkaline phosphatase organic phosphate substrates, is characterized by an initial short lag period of limited Ca2+ accumulation, followed by a period of rapid Ca2+ uptake, and finally, by a plateau period during which Ca2+ accumulation continued at a slower rate. FTIR spectra taken at timed intervals during the induction of mineralization revealed the presence of absorptions characteristic of protein, phospholipid, and mineral components in the CRMV. These became progressively more intense with time. To reveal underlying changes occurring during the successive stages of Ca2+ accumulation, FTIR spectra of nascent (or demineralized) CRMV were computer-subtracted from subsequent spectra, nulling on the C-H stretch modes characteristic of the lipid acyl chains. These difference spectra showed little change during early Ca2+ loading, revealing that mineral ions initially accumulated in a form similar to that present in nascent matrix vesicles (MV). During the period of rapid Ca2+ uptake prior to appearance of crystalline mineral, difference spectra revealed subtle changes in the carbonyl and amide nitrogen stretch modes indicative of protein conformational changes. The first definable mineral phase appeared late in the rapid Ca2+ uptake period and was a distinct, crystalline octacalcium phosphate (OCP)-like phase. With time, the OCP-like precursor became more apatitic in character. There was no evidence that any amorphous calcium phosphate phase formed during the MV mineralization sequence. The mature MV mineral phase closely resembled hydroxyapatite formed via an OCP precursor and was similar to other biological apatites that show a substantial incorporation of carbonate.

Animals↗

Image analysis of mineralized and non-mineralized type I collagen fibrils.

Turkey leg tendons at an early stage of mineralization have been thin sectioned and imaged by electron microscopy. At this stage collagen-associated mineral apatite was found to be present within both the gap and overlap zones. The earliest apatite occurs in a microcrystalline form which gives a rather generalized and characteristic density to both the gap and overlap zones; with subsequent development larger defined apatite crystals arise which span gap/overlap zones. Fourier transformation of such images revealed the major 67 nm axial repeat of the gap/overlap zone plus four other maxima corresponding to repeat spacings of 22, 16, 13, and 11 nm respectively. Computer imaging techniques were used to reconstruct images by using selected spatial frequencies from such transforms. In this manner the subperiodic distributions of mineral were visually enhanced. These subperiodicities are positioned in an asymmetric fashion over the entire D unit repeat aligning with the molecular orientation of the fibril. Analyses of both negatively stained collagen and computer-generated maps of collagen hydrophobicity were compared to the mineral distribution of collagen. Densitometric comparisons showed a positional correlation between the axial banding patterns of mineralized fibrils and those of negatively stained non-mineralized fibrils. Comparable spatial frequencies were also present in transforms between hydrophobic maps and mineral distribution of collagen. These results suggest that the lateral clusterings of hydrophobic residues which span the fibril at specific sites in both the gap and overlap zones serve to prohibit early mineral deposition. This observed hydrophobic influence in combination with the gap space appear as contributing factors in the observed axial distribution of mineral within collagen.

Amino Acids↗

Mineral concentrations in hair as indicators of mineral status: a review.

Mineral content of hair is affected by season, breed, hair color within and between breeds, sire, age and body location. Seasonal effects may be due to stage of growth of hair and to changes caused by perspiration, surface contamination and diet. Breed and sire effects on mineral content of hair complicate prediction of nutritional status based on hair analyses because, in many commercial cattle, neither breed nor sire is known. Hair from young animals may be lower in Zn, Mn and Fe, but is higher in Na, Ca, Cu and K than that from older animals. Pigmented hair apparently is higher in Ca, Mg, K and NA than white hair, but trace mineral concentrations are similar in hair of different colors. The effect of body location on mineral content of hair may be due to differences in surface contamination, differences in hair growth cycles and differences in texture of the hair. Concentrations of Ca, P and Cu in hair are not affected by dietary intake of these minerals. Zn and Se contents of hair may reflect dietary intake. Information on other required minerals in lacking. Pb, As and, possibly, Cd levels in hair may be related to dietary or environmental exposure. Because of the many factors that cause variation in mineral content of hair, hair analyses are not likely to be precise indicators of the mineral status of animals. Hair analyses may help to detect severe deficiencies of some required minerals or exposure to some heavy metals. However, if hair analyses are to be conducted, care must be taken to compare values from test animals with those from animals of similar breed, sex, season, sire and color. In addition, new hair growth should be analyzed, environmental contamination should be minimized and the hair samples should be cleaned before analyses.

Age Factors↗

Urolithiasis in dogs. I: Mineral prevalence and interrelations of mineral composition, age, and sex.

OBJECTIVE: To compile and statistically analyze selected data from a large number of canine urinary calculi. SAMPLE POPULATION: 11,000 specimens: 5,781 from female dogs, 5,215 from male dogs, and 4 from dogs of unrecorded sex. PROCEDURE: Records were used to compile information from all canine calculi analyzed between July 1981 and January 1994. Interrelations of mineral composition, location of specimens within the urinary tract, age and sex of affected dogs, and number of previous episodes of urolithiasis were determined. RESULTS: Approximately 70% of the specimens were from a first episode of urolithiasis. Calculi were located in the urinary bladder of 93.1% of females and 79.0% of males, and in the upper urinary tract of 4% of females and 2% of males. Calculi were found in multiple sites in 23.1% of males and 5.2% of females. Significantly higher proportions of struvite, apatite, and urate were found in uroliths from females; oxalate, cystine, silica, and brushite were significantly more prevalent in males. Sixty-one percent of specimens from males and 29% from females were composed of a single mineral substance. The most common mineral combination of 2 or more minerals included struvite and apatite. An additional 67 specimens from male dogs and 49 from female dogs contained other mineral combinations. In 48% of specimens from males and nearly 62% of specimens from females, the minerals formed several distinct layers of differing composition. CONCLUSIONS: Male and female dogs from urinary calculi composed of 1 or more of several distinct minerals. Prevalence of canine uroliths differs between ages and between the sexes. Many specimens contain complex layering of minerals; most specimens were found in the urinary bladder. CLINICAL RELEVANCE: Sex and age of dogs, mineral types of likely calculi in males versus females, and their anatomic location are important considerations for clinicians when evaluating risk in dogs with urolithiasis.

Age Distribution↗

Mechanism by which MLO-A5 late osteoblasts/early osteocytes mineralize in culture: similarities with mineralization of lamellar bone.

The mechanisms whereby bone mineralizes are unclear. To study this process, we used a cell line, MLO-A5, which has highly elevated expression of markers of the late osteoblast such as alkaline phosphatase, bone sialoprotein, parathyroid hormone type 1 receptor, and osteocalcin and will mineralize in sheets, not nodules. In culture, markers of osteocytes and dendricity increase with time, features of differentiation from a late osteoblast to an early osteocyte. Mineral formation was examined using transmission electron microscopy, scanning electron microscopy with energy-dispersive X-ray analysis, and atomic force microscopy. At 3-4 days of culture, spheres of approximately 20-50 nm containing calcium and phosphorus were observed budding from and associated with developing cellular projections. By 5-6 days, these calcified spheres were associated with collagen fibrils, where over time they continued to enlarge and to engulf the collagen network. Coalescence of these mineralized spheres and collagen-mediated mineralization were responsible for the mineralization of the matrix. Similar calcified spheres were observed in cultured fetal rat calvarial cells and in murine lamellar bone. We propose that osteoid-osteocytes generate spherical structures that calcify during the budding process and are fully mineralized on their developing cellular processes. As the cellular process narrows in diameter, these mineralized structures become associated with and initiate collagen-mediated mineralization.

Animals↗

A theoretical analysis of the contributions of remodeling space, mineralization, and bone balance to changes in bone mineral density during alendronate treatment.

In patients with osteoporosis, alendronate treatment causes an increase in bone mineral density (BMD) and a decrease in fracture incidence. Alendronate acts by changing the bone remodeling process. Changes in bone remodeling resulting in decreased remodeling space, increased bone balance per remodeling cycle, and increased mineralization (ash mass/bone mass) have all been associated with alendronate treatment. Understanding the relative contributions of these parameters to BMD increases could help predict the utility of long-term (>10 years) or intermittent treatment strategies, as well as treatment strategies in which another pharmaceutical is administered concurrently. We have developed a computer simulation of bone remodeling to compare the contributions of focal bone balance and mineralization on BMD by simulating alendronate treatment using a bone balance method (decreased remodeling space, increased focal bone balance, uniform bone mineralization) and a mineralization method (decreased remodeling space, neutral focal bone balance, varying bone mineralization). Although both methods are able to predict BMD increases caused by alendronate over short periods, our findings suggest that the mineralization method may be more descriptive of long-term alendronate treatment. This implies that mineralization may be a larger contributor to BMD changes caused by alendronate than the focal bone balance. Based on this finding we offer a hypothesis to describe how remodeling space, focal bone balance, and mineralization each contribute to alendronate-induced BMD changes. Future analyses with this method could be used to identify improved dosing regimens and to predict which osteoporosis treatments would best complement each other.

Alendronate↗

Bone mineral density in patients with ossification of the posterior longitudinal ligament. Minimal decrease of bone mineral density with aging.

STUDY DESIGN: Bone mineral density of individuals with ossification of the posterior longitudinal ligament and that of normal people was determined by dual-energy x-ray absorptiometry. OBJECTIVES: To determine whether bone mineral density in the people with ossification of the posterior longitudinal ligament is higher than that in normal individuals even in body parts other than the spine, and to evaluate the relation between bone mineral density and age in patients with ossification of the posterior longitudinal ligament. SUMMARY OF BACKGROUND DATA: It is unknown whether the bone mineral density of patients with ossification of the posterior longitudinal ligament is greater in body parts other than the spine. If so, it provides a basis for the theory that certain systemic factors are involved in the pathogenesis of ossification of the posterior longitudinal ligament. Because bone mineral density decreases physiologically after middle age, the influence of age must be considered in evaluating bone mineral density. METHODS: In the rib area and upper and lower limb areas, which are not affected by ossification of the spinal ligament, bone mineral density of 45 men with ossification of the posterior longitudinal ligament of the cervical spine was compared with that of 25 men without ossification of the posterior longitudinal ligament (normal group). RESULTS: Bone mineral density was higher in the group with ossification of the posterior longitudinal ligament in each part and significantly higher in the rib and lower limb areas (rib: P < 0.01, lower limb: P < 0.05). The age-related decrease was significantly less in the group with ossification of the posterior longitudinal ligament (rib: P < 0.01, upper limb: P < 0.05, lower limb: P < 0.01). CONCLUSIONS: Systemic factors that increase bone mineral density appear to be involved in the pathogenesis of ossification of the posterior longitudinal ligament, and these factors may be activated after middle age.

Absorptiometry, Photon↗

Effects of long-term intervention with Lactobacillus helveticus-fermented milk on bone mineral density and bone mineral content in growing rats.

BACKGROUND: Lactobacillus helveticus-fermented milk has been shown to increase calcium absorption compared to ordinary sour milk. In the present study the possible effect of L. helveticus-fermented milk on bone was studied in growing rats. METHODS: Spontaneously hypertensive male rats, which develop an osteoporotic bone disorder with age, were randomized into 5 groups (n = 10) receiving milk fermented with L. helveticus 16H and, as reference drinks, milk fermented with L. helveticus and Saccharomyces cerevisiae, sour milk, skim milk or water, for 14 weeks. After the intervention bone mineral density and bone mineral content were measured by dual-energy X-ray absorptiometry. The femur weight, length and volume were measured before ashing. From the ashes the weight and mineral content were assessed. RESULTS: As the body weight gain differed significantly between the groups, the results were related to the body weight. The L. helveticus-fermented milk intervention significantly increased the bone mineral density and bone mineral content compared to the sour milk, skim milk and water interventions. The mean values of the bone mineral density and bone mineral content were higher in the L. helveticus-fermented milk group compared to the Saccharomyces-fermented milk group but the difference was not statistically significant. CONCLUSION: L. helveticus-fermented milk increases bone mineral density and bone mineral content in relation to body weight in the long-term feeding of growing rats. The mechanism of L. helveticus remains to be discovered.

Absorptiometry, Photon↗

Osteopontin deficiency increases mineral content and mineral crystallinity in mouse bone.

Fourier transform infrared microspectroscopy (FTIRM) and infrared imaging (FTIRI) were used to characterize the mineral in bones of two different lines of Opn-deficient (Opn-/-) mice and their background-matched wild-type controls (Opn+/+). Sections of tibia and femur from 12-week-old and 16-week-old mice were evaluated with a spatial resolution between 10 microm (FTIRM) and 7 microm (FTIRI). FTIRI was used to examine 400 microm x 400 microm areas in cortical bone and trabecular bone and FTIRM examined selected 20 microm x 20 microm areas at sites within these anatomically defined areas. Despite the absence of an obvious phenotype in Opn-deficient mice, being undetectable by radiographic and histological methods, FTIRM analyses revealed that the relative amount of mineral in the more mature areas of the bone (central cortical bone) of Opn-knockout mice was significantly increased. Moreover, mineral maturity (mineral crystal size and perfection) throughout all anatomic regions of the Opn-deficient bone was significantly increased. The 2-dimensional, color-coded data (images) produced by FTIRI showed similar increases in mineral maturity in the Opn-/- bone, however, the crystallinity parameters were less sensitive, and significance was not achieved in all areas analyzed. Nonetheless, the findings of increased mineral content and increased crystal size/perfection in both lines of Opn-deficient mice at both ages are consistent with in vitro data indicating that Opn is a potent inhibitor of mineral formation and mineral crystal growth and proliferation, and also support a role for Opn in osteoclast recruitment and function.

Animals↗

Inhibition of diphosphonate-blocked bone mineralization. Evidence that calcitonin promotes mineralization.

There is much experimental evidence which indicates that calcitonin in hibits bone mineral resorption, but there are few data available in support of the proposal that calcitonin may also promote mineralization. Ethane-1-hydroxy-1,1-diphosphonate (EHDP) administered to immature rats inhibited mineralization as evidenced by widened tibial epiphyseal plates and decreased bone ash to dry weight ratios. Concurrent dosing with salmon calcitonin (SCT) prevented or reversed the EHDP-blocked mineralization in a dose dependent manner. Administration of SCT during the period after EHDP treatment significantly improved mineralization of tibial epiphyseal plates as shown by plate width narrowing and increased uptake of radioactive calcium. These results suggest that SCT increased mineralization in EHDP-treated rats, and provide supportive evidence for the proposal that calcitonin may also promote mineralization, in addition to its well known ability to inhibit bone mineral resorption.

Age Factors↗

Raman spectroscopic evidence for octacalcium phosphate and other transient mineral species deposited during intramembranous mineralization.

UNLABELLED: To understand early mineralization events, we studied living murine calvarial tissue by Raman spectroscopy using fibroblast growth factor 2 (FGF2)-soaked porous beads. We detected increased levels of a transient phase resembling octacalcium phosphate in sutures undergoing premature suture closure. INTRODUCTION: Several calcium phosphates have been postulated as the earliest inorganic precursors to bone mineral. They are unstable and have not been previously detected in tissue specimens. Whether the same intermediates are formed in sutures undergoing premature closure is also unknown. METHODS: Six coronal suture tissue specimens from fetal day 18.5 B6CBA F1/J wild-type mice were studied. Three sutures specimens were treated with FGF2-soaked heparin acrylic beads to induce accelerated mineralization and premature suture closure. Three control specimens were treated with empty heparin acrylic beads. All sutures were maintained as organ cultures to permit repeated spectral analyses at 12-24 h intervals over a 72-h period. RESULTS: During the first 24 h, the spectra contained bands of octacalcium phosphate (OCP) or an OCP-like mineral. The main phosphorus-oxygen stretch was at 955 cm(-1), instead of the 957-959 cm(-1) seen in bone mineral, and there was an additional band at 1010-1014 cm(-1), as expected for OCP. A broad band was found at 945 cm(-1), characteristic of a highly disordered or amorphous calcium phosphate. An increased amount of mineral was observed in FGF2-treated sutures, but no qualitative differences in Raman spectra were observed between experimental and control specimens. CONCLUSIONS: Inorganic mineral deposition proceeds through transient intermediates, including an OCP-like phase. Although this transient phase has been observed in purely inorganic model systems, this study is the first to report OCP or an OCP-like intermediate in living tissue. Raman microspectroscopy allows observation of this transient mineral and may allow observation of other precursors as well.

Animals↗

Biological impact on mineral dissolution: application of the lichen model to understanding mineral weathering in the rhizosphere.

Microorganisms modify rates and mechanisms of chemical and physical weathering and clay growth, thus playing fundamental roles in soil and sediment formation. Because processes in soils are inherently complex and difficult to study, we employ a model based on the lichen-mineral system to identify the fundamental interactions. Fixed carbon released by the photosynthetic symbiont stimulates growth of fungi and other microorganisms. These microorganisms directly or indirectly induce mineral disaggregation, hydration, dissolution, and secondary mineral formation. Model polysaccharides were used to investigate direct mediation of mineral surface reactions by extracellular polymers. Polysaccharides can suppress or enhance rates of chemical weathering by up to three orders of magnitude, depending on the pH, mineral surface structure and composition, and organic functional groups. Mg, Mn, Fe, Al, and Si are redistributed into clays that strongly adsorb ions. Microbes contribute to dissolution of insoluble secondary phosphates, possibly via release of organic acids. These reactions significantly impact soil fertility. Below fungi-mineral interfaces, mineral surfaces are exposed to dissolved metabolic byproducts. Through this indirect process, microorganisms can accelerate mineral dissolution, leading to enhanced porosity and permeability and colonization by microbial communities.

Journal Article↗

[The mineral requirements and mineral status in pregnancy].

Recommendations for mineral intakes during pregnancy differs around the world, effecting the inadequacy of knowledge about mineral requirements in human reproductions. The most important minerals for the pregnant women and their outcome are iron, calcium and zinc. It is very difficult the precise determination of amount of minerals needed because the appropriate techniques used can not be used for pregnant woman. Because of hormonal changes during pregnancy the blood levels of minerals are not the best index for assessment of mineral status. The prepregnancy nutrition is one of the most important determinant of nutritional status and pregnancy outcome. There are lacking of cut-off values in serum for the most minerals, deficiency to be screened. Therefore, the assessment of nutritional status during pregnancy serves seriously problem. More research is required before we can confident about advising women to use mineral supplements during pregnancy.

Female↗

Bone mineralization in preterm infants fed human milk with and without mineral supplementation.

The bone mineral status of healthy preterm infants fed maternal milk was compared with that of similar infants fed maternal milk with mineral supplementation. Fifty infants with birth weight less than 1600 g were fed human milk for 1 week until reaching an intake of 120 kcal/kg/d. Thereafter, infants were assigned randomly to one of three diets: (1) continued unsupplemented human milk, providing an intake of 40 to 50 mg/kg/d calcium and 23 to 30 mg/kg/d phosphorus; (2) human milk mixed with a high mineral containing formula, providing total intakes of 130 mg/kg/d calcium and 68 mg/kg/d phosphorus; or (3) human milk alone for 1 additional week, followed by human milk mixed with a powdered fortifier, providing total intakes of 160 mg/kg/d calcium and 90 mg/kg/d phosphorus. Infants fed human milk with formula supplementation, but not those fed human milk with fortifier, had significantly higher serum phosphorus concentrations and significantly lower serum alkaline phosphatase concentrations than did those fed unsupplemented human milk (P less than 0.01). Bone mineral content of the humerus, determined by photon absorptiometry, however, was similar in all three groups; values averaged 0.104 g/cm at the beginning of the study, and remained unchanged irrespective of mineral supplementation. Shortly before hospital discharge, study diets were discontinued and infants were fed standard proprietary formula or were nursed by their mothers. At 44 weeks postconceptional age (7 to 10 weeks after change in diet), infants were reexamined. Serum phosphorus concentrations increased, serum alkaline phosphatase concentrations decreased, and bone mineral content more than doubled to values comparable with those in term infants. Results at follow-up were comparable for all three initial diet groups and for infants who were formula-fed or breast-fed after hospital discharge. The lack of any significant effect of early maternal milk supplementation on bone mineralization by 44 weeks postconceptional age suggests that these methods of supplementation of maternal milk may not be warranted for healthy preterm infants.

Bone Development↗

Oim mice exhibit altered femur and incisor mineral composition and decreased bone mineral density.

To investigate the role of the pro alpha 2(I) collagen chains of type I collagen in mineralization we used the oim (osteogenesis imperfecta model) mouse as our model system. The oim/oim mouse (homozygous for a null mutation in its COL1A2 gene of type I collagen) fails to synthesize functional pro alpha 2(I) collagen chains, synthesizing only homotrimers of pro alpha 1(I) collagen chains. To evaluate the role of pro alpha 2(I) collagen in type I collagen structure/function in mineralized tissues, we examined age-matched oim/oim, heterozygous (oim/+), and wild-type (+/+) mouse femurs and incisors for mineral composition (calcium, phosphorus, magnesium, fluoride, sodium, potassium, and chloride) by neutron activation analyses (NAA), and bone mineral content (BMC) and bone mineral density (BMD) by dual-energy X-ray absorptiometry (DEXA) in a longitudinal study (7 weeks to 16 months of age). NAA demonstrated that oim/oim femurs had significant differences in magnesium, fluoride, and sodium content as compared with +/+ mouse femurs, and oim/oim teeth had significant differences in magnesium content as compared to +/+ teeth. The ratio of calcium to phosphate was also significantly reduced in the oim/oim mouse femurs (1.58 +/- 0.01) compared with +/+ femurs (1.63 +/- 0.01). DEXA demonstrated that oim/oim mice had significantly reduced BMC and BMD as compared to oim/+ and +/+ mice. Serum and urine calcium, magnesium, and phosphorus levels, and Ca(47) absorption across the gut were equivalent in oim/oim and +/+ mice, with no evidence of hypercalciuria. These studies suggest that the known decreased biomechanical properties of oim/oim bone reflect both altered mineral composition as well as the decreased BMD, which further suggests that the presence of alpha2(I) chains plays an important role in mineralization.

Absorptiometry, Photon↗

Migration of mineral hydrocarbons into foods. 5. Miscellaneous applications of mineral hydrocarbons in food contact materials.

Polystyrene and acrylonitrile/butadiene/styrenes (ABS) containers for individual serving portions (80 samples of milk, cream, butter, margarine and spreads) used in the catering industry were found to contain 1-4% mineral oil. Levels of mineral oil migrating into the foods were generally low (< 5-15 mg/kg) except in one instance where levels of 45-85 mg/kg were detected in a low fat spread, and this was attributed to mineral hydrocarbon transfer from an adhesive used in the lidding. Analysis of wine bottle corks (105 samples from 11 different countries) indicated that 50% had been treated with mineral wax or mineral oil, although in all cases mineral hydrocarbon contamination of the wine was < 0.2 mg/l. Waxed paper discs sold for home-use for covering the surface of jams and preserves were found to be coated with 100 mg/dm2 of mineral hydrocarbons. However, in experiments with a variety of jams and preserves levels of migration were not significant, ranging from 0.15 to 1.2 mg/kg.

Acrylic Resins↗

The influence of a mineralizing mouthrinse on the mineral contents and on the pH of dental plaque.

The main objective of this study was to evaluate the effects of a single use of a mineralizing mouthrinse on dental plaque pH and on its mineral contents: an additional objective was to examine the effects of an oral prophylaxis and scaling on the same response variables. A total of 22 volunteer dental students (14 female and 8 male) participated in the study. The mineralizing mouthrinse contained calcium, phosphate, strontium and fluoride ions. Following a 48-hour period without oral hygiene and 2 hours after breakfast, dental plaque was collected twice from each participant for the evaluation of the effects of the oral prophylaxis and scaling, and twice more for the evaluation of the effects of the mineralizing mouthrinse. The pH was measured in vitro with a microelectrode and the mineral contents were determined by atomic emission spectrometry. The results demonstrate that the average post-prophylaxis pH was higher than the average pre-prophylaxis pH, and that a variation of the average contents of some minerals in the dental plaque was also observed after prophylaxis compared to the contents prior to prophylaxis. Although there was a significant reduction in the Fe content after the rinse with the mineralizing solution, no significant variation on the average pH was detected.

Adolescent↗