The Effect of Age and Gender on Al, B, Ba, Ca, Cu, Fe, K, Li, Mg, Mn, Na, P, S, Sr, V, and Zn Contents in Rib Bone of Healthy Humans

The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.     

NAA-SLR and ICP-AES Application in the Assessment of Mass Fraction of 19 Chemical Elements in Pediatric and Young Adult Prostate Glands

The effect of age on the mass fraction of 19 chemical elements in the intact prostate of 50 apparently healthy 0–30-year-old males was investigated by neutron activation analysis with high-resolution spectrometry of short-lived radionuclides and inductively coupled plasma atomic emission spectrometry. Mean values (M ± standard error of the mean) for mass fraction (in milligrams per kilogram, on dry weight basis) of chemical elements were as follows: Al, 77?±?17; B, 1.31?±?0.29; Ba, 4.0?±?1.2; Br, 37.7?±?4.3; Ca, 1,536?±?189; Cl, 13,414?±?949; Cu, 12.3?±?2.1; Fe, 132?±?11; K, 11,547?±?468; Li, 0.064?±?0.009; Mg, 922?±?89; Mn, 1.88?±?0.16; Na, 9,834?±?411; P, 6,741?±?335; S, 8,034?±?251; Si, 199?±?34; Sr, 1.40?±?0.19; and Zn, 277?±?33. The upper limit of mean mass fraction of V was ≤0.24. This work revealed that there is significant tendency for the mass fractions of Ca, K, Mg, and Zn in the prostate tissue of healthy individuals to increase with age from the time of birth up to 30 years. It means that Ca, K, Mg, and Zn mass fractions in prostate tissue are the androgen-dependent parameters. Our finding of a positive correlation between the prostatic Zn and Ca, K, Mg, P, and S mass fractions indicates that there is a special relationship of Zn with some main electrolytes (Ca, K, and Mg) and with P- and S-containing compounds in the prostate. It was shown also that high levels of Al, B, Ba, Br, Cl, Li, Na, and Sr mass fraction in prostate tissue do not indicate a direct involvement of these elements in the reproductive function of the prostate.     

Effect of crude protein and phosphorus level on growth performance,bone mineralisation and phosphorus,calcium and nitrogen utilisation in grower-finisher pigs

Two experiments in a 2?×?2 factorial arrangement were conducted to evaluate the effect of crude protein (CP) (130 vs. 200 g/kg) and phosphorus (P) (4.0 vs. 6.0 g total P/kg) level in a phytase supplemented diet (500 FTU [phytase units]/kg) in grower-finisher pigs. Owing to the design of the experiment, as dietary P level increased, there was also an increase in dietary calcium (Ca) level in order to maintain a dietary Ca to P ratio of 1.6:1. In Experiment 1, four diets were fed to 56 pigs (n?=?14, initial body weight [BW] 36.7?±?4.2 kg) to investigate the interaction between CP and P on growth performance, bone mineralisation and digesta pH. Experiment 2 consisted of 16 entire male pigs (n?=?4; offered identical diets to that offered in Experiment 1) for the determination of total tract apparent digestibility and nitrogen (N), P and Ca utilisation. There was an interaction between CP and P level on bone ash, bone P and bone Ca concentrations (p?<?0.05). Pigs offered low CP–low P diets had a higher bone ash, P and Ca concentrations than pigs offered high CP–low P diets. However, there was no effect of CP level at high P levels on bone ash, P and Ca concentrations. Pigs offered low P diets had a lower ileal pH compared with pigs offered high P diets (p?<?0.05). In conclusion, offering pigs a high CP–low P, phytase-supplemented diet resulted in a decrease in bone mineralisation.     

Heavy Metals in Antarctic Notothenioid Fish from South Bay, Livingston Island, South Shetlands (Antarctica)

The Pb, Cd, Cu, Zn, and Mn contents of the liver, spleen, muscle, bones, scales, gills, and the whole body of 3- to 7-year-old notothenioid Antarctic cod (Notothenia coriiceps, Richardson, 1844) were measured. The highest heavy metal concentrations obtained are as follows: Cd in liver, the mean value was 1.36 ± 0.19 mg/kg dry weight (wt); Pb and Zn in spleen, the mean values were 3.33 ± 0.86 and 143.97 ± 16.17 mg/kg dry wt, respectively; Cu in gills, 3.76 ± 1.16 mg/kg dry wt; and Mn in scales, 14.80 ± 4.77 mg/kg dry wt. The comparison with the data reported up to now shows that the metal concentrations varied within relative wide ranges. These first data obtained could be used as a baseline to investigate further relationships among metal contents in fish, their diet, and habitat.     

Influence of different dietary calcium levels on the digestibility of Ca,Mg, and P in captive‐born juvenile Galapagos giant tortoises (Geochelone nigra)

Calcium (Ca) and phosphorus (P) are very important minerals in reptile nutrition, but many diets still are not balanced. To achieve optimal growth, including a healthy skeleton and a strong shell, a well‐balanced supply with these minerals is prerequisite. The purpose of this study was to evaluate the digestibility of diets with different calcium levels, with special emphasis on the digestibility of minerals. Fourteen captive‐born juvenile Galapagos giant tortoises of the Zurich and Rotterdam Zoos were used. The animals were housed indoors at a mean temperature of 23°C and 25°C, and at 65% and 60% humidity, respectively. The animals from the same zoo were fed the same diet, which consisted of vegetables, herbs, and a mixture of different Ca sources. Daily mixed fecal samples of all tortoises were collected from day 8 to day 18. A Weender analysis was performed and the HCl‐insoluble ash was used as an indigestible indicator (marker) for the determination of the apparent digestibility. The Ca content of the mixed feedstuffs of diet I was 1.43% on a dry matter basis, and the Ca:P ratio in the food was 3.9:1. In diet II, the Ca content was 2.06% on a dry matter basis, and the Ca:P ratio in the food was 4.8:1. Diet III contained 7.33% of Ca on a dry matter basis, and the Ca:P ratio in the food was 6.7:1. The digestibility of Ca in diet I was 42%. The other examined minerals, Mg and P, had a digestibility of 54% and 84%, respectively. In diet II, the digestibility of Ca was 63%, of Mg 76%, and of P 88%, and in diet III the digestibility of Ca was 82%, of Mg 92%, and of P 91%. The results of this study indicated that higher Ca concentrations in the diet led to an increased apparent digestibility of Ca, Mg, and P. The influence of an increased fat and decreased fiber content in diet III concerning digestibility is discussed. Zoo Biol 20:367–374, 2001. © 2001 Wiley‐Liss, Inc.     

Mineral composition variation in the shells of freshwater mussel Anodonta woodiana at different growth stages

The levels of mineral element Na, Mg, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Mo, Al, As, Ag, Cd, and Tl were quantified in the whole shells of the freshwater bivalve Anodonta woodiana at three different growth stages (i.e. J1 juveniles of 1 month old, J2 juveniles of 3.5 months old, and adults of 36 months old). The concentrations of Na and Al were different between different growth stages (p < 0.05). The highest Na concentrations (2715 ± 86 μg/g dry weight) were found in J2 juveniles. The highest Al concentrations (303.9 ± 5.95 μg/g dry weight) were found in J1 juveniles. Manganese concentrations (517.0 ± 47.98 μg/g dry weight) were significantly higher in J2 juveniles than in J1 juveniles (432.3 ± 9.87 μg/g dry weight) (p < 0.05). Copper concentrations (27.32 ± 0.15 μg/g dry weight) were significantly higher in J1 juveniles than in J2 juveniles (26.21 ± 0.86 μg/g dry weight) and adults (24.74 ± 1.43 μg/g dry weight) (p < 0.05). Burdens of Na, Ca, Mn, Fe, Co, Cu, Mo, Ag, and Tl were positively correlated with the shell length (p < 0.05). These findings can possibly contribute to an understanding of elemental requirements for shell growth and, hence, facilitate improvement of survival and growth rates during artificial mussel culture.     

ELEMENTAL COMPOSITION,CORRELATIONS, AND RATIOS WITHIN A POPULATION OF STAURASTRUM PLANCTONICUM (ZYGNEMATALES): AN X-RAY MICROANALYTICAL STUDY1

Individual cells of Staurastrum planctonicum (Teil.) within a mixed freshwater phytoplankton sample were analyzed by scanning electron microscope X-ray microanalysis to determine their elemental composition. X-ray emission spectra routinely showed clear peaks of P, S, and Cl, plus monovalent (Na, K, and divalent (Mg, Ca) cations. Si and Cu were also present in lower quantities. Concentrations of individual elements (expressed as mmol.kg⁻¹ dry weight) varied widely among cells, with values over the sample population approximating to a normal distribution. Although intracellular anion and cation levels varied considerably, significant correlations occurred between concentrations of monovalent and divalent cations (mean ratio 1.4), major diffusible anions and cations (mean ratio 1,2), and total levels of electropositive and electronegative elements (mean ratio 1.2). The monovalent cations of K and Na occurred at a mean ratio of 1.2 and were not significantly correlated. Concentrations of individual elements (except Si) showed clear positive correlations within the analyses, with 12 highly significant (99% probability) correlations out of 36 possible combinations. Principal factor analysis showed that elemental correlations were determined by two major factors, with two resulting groups of elements—(Na, S, Cl, Ca, Cu) and (Mg, P, K). Statistical relationships between elements followed a clear correlation pattern, which retained its characteristics even when elemental concentrations were expressed per unit P rather than per unit dry weight. Elemental concentrations were closely similar in matching, but not nonmatching, smicells. The statistical pattern of elemental associations noted in Staurastrum parallels that seen in X-ray micro-analytical studies of other algae but differs in detail. This pattern of statistical associations has biological implications in terms of cell compartmentation, characterization of different cell types, and cell interactions with their environment.     

Effects of Ca and Mg concentrations in seawater on the growth and energy budget of juvenile Paralichthys olivaceus (Temminck & Schlegel, 1846)

Effects of seawater calcium (Ca) and magnesium (Mg) concentrations on the growth and energy budget of juvenile Paralichthys olivaceus (Temminck & Schlegel, 1846) were investigated at 20°C and a salinity of 30 psu. The Ca/Mg ratio (Ca : Mg = 1 : 3) in the experimental water was kept constant. Five treatments were set: C1, C2, C3, C4, and C5, and the Ca and Mg concentrations were 700, 1100, 1600, 2200, and 2800 (mg L^?1), respectively. After a 60‐day feeding trial the P. olivaceus survival rates were not affected significantly by Ca or Mg concentrations in the range of 700–2800 mg L^?1. However, the specific growth rates (SGR) and weight gain (WG) of all treatments decreased with ascending Ca and Mg concentrations. The Ca and Mg concentrations had a strong influence on various energy parameters, namely, energy deposited for growth (G), energy lost for respiration (R), and energy lost in excretion (U), but had little influence on energy lost in feces (F). This indicated that the growth rate differences under different concentrations of Ca and Mg mainly resulted from differences of assimilation efficiency and energy channeled into respiration. The highest net growth efficiency was attained at the lowest concentration of Ca and Mg in seawater, and the higher concentrations of Ca and Mg increased the energy channeled to respiration and excretion, which led to significant reduction in growth. Therefore, the optimal growth of P. olivaceus could be obtained by regulating the concentration of Ca and Mg at 700 mg L^?1, where the average energy budget was: 100C (100% energy consumed in food) = 47.21 (±0.63) G + 32.89 (±0.42) R + 16.71 (±0.56) F + 3.19 (±0.05) U.     

Assessment of markers of bone formation under controlled environmental factors and their correlation with serum minerals in adult sheep as a model for orthopaedic research

Eighteen healthy skeletally mature (3 years old) ewes, with an average weight of 45 kg, of the Portuguese Churra da Terra Quente breed were used to evaluate the normal values of total and bone-specific isoform of alkaline phosphatase serum activities (ALP and BALP, respectively) and serum osteocalcin (OC) and their correlation with the serum minerals - calcium (Ca), phosphorus (P), magnesium (Mg) and ionized calcium (Ca(2+)). The sheep were maintained under controlled environmental conditions (constant diurnal photoperiod cycle and identical husbandry and feeding) for six weeks before the collection of the blood samples. The measurement of the total ALP and serum minerals was performed with automated biochemistry analysers using the BioMérieux kits, the serum electrolyte Ca(2+) Diametrics Medical, Inc specific cassettes and the BALP and OC METRATM kits from QUIDEL Corporation. The mean +/- standard deviation values obtained were: total ALP 90.17 +/- 85.72 U/L, BALP 15.0 +/- 5.44 U/L, ratio BALP/ total ALP 29.28 +/- 24.22, OC 13.02 +/- 1.87 ng/mL, Ca 2.57 +/- 0.37 mmol/L, P 2.13 +/- 0.42 mmol/L, Mg 1.04 +/- 0.13 mmol/L, Ca(2+) 1.29 +/- 0.04 mmol/L. Significant correlations were observed between the total ALP and Ca (r = 0.5939; P = 0.05) and OC and Ca (r = 0.5706; P = 0.05). Reference to the serum values of bone turnover parameters in sheep could be of great value in research and could provide complementary non-invasive information on the bone healing process, particularly with regard to obtaining an early prognosis of fracture healing.     

Evaluation of the 3D spatial distribution of the Calcium/Phosphorus ratio in bone using computed-tomography dual-energy analysis

PurposeThe Calcium/Phosphorus (Ca/P) ratio was shown to vary between healthy bones and bones with osteoporotic symptoms. The relation of the Ca/P ratio to bone quality remains under investigation. To study this relation and determine if the ratio can be used to predict bone fractures, a non-invasive 3D imaging technique is required. The first aim of this study was to test the effectiveness of a computed-tomography dual-energy analysis (CT-DEA) technique developed to assess the Ca/P ratio in bone apatite (collagen-free bone) in identifying differences between healthy and inflammation-mediated osteoporotic (IMO) bones. The second aim was to extend the above technique for its application to a more complex structure, intact bone, that could potentially lead to clinical use.MethodsFor the first aim, healthy and IMO rabbit cortical bone apatite samples were assessed. For the second aim, some changes were made to the technique, which was applied to healthy and IMO intact bone samples.ResultsStatistically significant differences between healthy and IMO bone apatite were found for the bulk Ca/P ratio, low Ca/P ratio proportion and interconnected low Ca/P ratio proportion. For the intact bone samples, the bulk Ca/P ratio was found to be significantly different between healthy and IMO.ConclusionsResults show that the CT-DEA technique can be used to identify differences in the Ca/P ratio between healthy and osteoporotic, in both bone apatite and intact bone. With quantitative imaging becoming an increasingly important advancement in medical imaging, CT-DEA for bone decomposition could potentially have several applications.     

Bone calcium/phosphorus ratio determination using dual energy X-ray method

Non-invasive dual energy methods have been used extensively on osteoporosis diagnosis estimating parameters, such as, Bone Mineral Density (BMD) and Bone Mineral Content (BMC). In this study, an X-ray dual energy method (XRDE) was developed for the estimation of the bone Calcium-to-Phosphorous (Ca/P) mass ratio, as a bone quality index. The optimized irradiation parameters were assessed by performing analytical model simulations. X-ray tube output, filter material and thickness were used as input parameters. A single exposure technique, combined with K-edge filtering, was applied. The optimal X-ray spectra were selected according to the resulted precision and accuracy values. Experimental evaluation was performed on an XRDE system incorporating a Cadmium Telluride (CdTe) photon counting detector and three bone phantoms with different nominal mass Ca/P ratios. Additionally, the phantoms’ mass Ca/P ratios were validated with energy-dispersive X-ray spectroscopy (EDX). Simulation results showed that the optimum filter atomic number (Z) ranges between 57 and 70. The optimum spectrum was obtained at 100 kVp, filtered with Cerium (Ce), with a surface density of 0.88 g/cm². All Ca/P ratio measurements were found to be accurate to within 1.6% of the nominal values, while the precision ranged between 0.91 and 1.37%. The accuracy and precision values of the proposed non-invasive method contributes to the assessment of the bone quality state through the mass Ca/P ratio determination.     

PTHrP1-34对荷瘤小鼠骨代谢与肿瘤生长情况的影响

目的研究甲状旁腺激素相关蛋白1-34（PTHrP1-34）对荷瘤小鼠骨代谢的影响,同时观察肿瘤生长情况。方法对照组、模型组、实验组4周龄健康雌性BALB/c小鼠各12只,模型组和实验组采用乳腺癌组织块悬浊液注射法制备小鼠乳腺癌模型,10d后模型组每日予以生理盐水腹腔注射,实验组每日予以PTHrP1-34400μg/（kg.bw）腹腔注射。用药35 d后测全身骨密度（BMD）、股骨灰干重比、骨代谢相关血清指标[钙（Ca）、磷（P）、碱性磷酸酶（ALP）、骨钙素（OC）、Ⅰ型胶原C-末端交联顶端肽β（β-CTX）、骨唾液酸蛋白（BSP）],剥离肿瘤比较体积与质量。结果各组Ca水平差异无显著性（P〉0.05）。与对照组和模型组比较,实验组P、β-CTX、BSP等反映骨吸收的指标显著升高（P〈0.01或P〈0.05）,总ALP、BGP等反映骨形成的指标显著降低（P〈0.01或P〈0.05）;实验组BMD、股骨灰干重比均显著降低（P〈0.01）。与对照组相比,模型组各指标变化差异无显著性。实验组肿瘤体积和质量显著升高（P〈0.01）。结论在PTHrP1-34的作用下,荷瘤小鼠骨吸收大于骨形成,造成溶骨性骨破坏,骨密度降低,骨破坏释放的细胞因子可能促进肿瘤生长。     

The effect of age and gender on 38 chemical element contents in human iliac crest investigated by instrumental neutron activation analysis

ProjectTo understand the role of major, minor, and trace elements in the etiology of bone diseases including osteoporosis, it is necessary to determine the normal levels and age-related changes of bone chemical elements.ProcedureThe effect of age and gender on 38 chemical element contents in intact iliac crest of 84 apparently healthy 15–55 years old women (n=38) and men (n=46) was investigated by neutron activation analysis.ResultsMean values (M±SEM) for mass fraction (on dry weight basis) of Ca, Cl, Co, Fe, K, Mg, Mn, Na, P, Rb, Sr, and Zn for both female and male taken together were Ca – 169±3 g/kg, Cl – 1490±43 mg/kg, Co – 0.0073±0.0024 mg/kg, Fe – 177±24 mg/kg, K – 1820±79 mg/kg, Mg – 1840±48 mg/kg, Mn – 0.316±0.013 mg/kg, Na – 4970±87 mg/kg, P – 79.7±1.5 g/kg, Rb – 1.89±0.22 mg/kg, Sr – 312±15 mg/kg, and Zn – 65.9±3.4 mg/kg, respectively. The upper limit of mean contents of Cs, Eu, Hg, Sb, Sc, and Se were Cs≤0.09 mg/kg, Eu≤0.005 mg/kg, Hg≤0.005 mg/kg, Sb≤0.004 mg/kg, Sc≤0.001 mg/kg, and Se≤0.1 mg/kg, respectively. In all bone samples the contents of Ag, As, Au, Ba, Br, Cd, Ce, Cr, Gd, Hf, La, Lu, Nd, Sm, Ta, Tb, Th, U, Yb, and Zr were under detection limits.ConclusionsThe Ca, Mg, and P contents decrease with age, regardless of gender. Higher Ca, Mg, P, and Sr mass fractions as well as lower Fe content are typical of female iliac crest as compared to those in male bone.     

The effect of sodicity on cotton: plant response to solutions containing high sodium concentrations

Solution culture was used to investigate whether the high solution Na concentrations and Na:Ca ratios found in sodic soils could directly affect the early growth and nutrient uptake of cotton (Gossypium hirsutum L.). Cotton was grown in nutrient solutions with three Na:Ca ratios (46:1, 4:1 and 0.2:1 mM) and three electrical conductivities (EC) (2.5, 4.25 and 6 dS m^?1) combined in a factorial design with four replicates. Most cotton growth parameters (including shoot and root dry weight, fruit number and weight) were unaffected by increasing solution EC or Na:Ca ratio, but at the highest Na concentration (56.6 mM), plant height was reduced. It was concluded that young cotton has the ability to tolerate solution Na concentrations up to those found in moderately sodic soils. Increasing solution Na:Ca increased plant root and shoot concentrations and plant accumulation for Na, and decreased them for Ca. Increasing EC also increased plant Na concentration and accumulation. Shoot K and P concentrations decreased with EC, but actually increased as the sodicity (Na:Ca ratio) of the nutrient solution increased. The results suggest that the low K and P concentrations commonly found in cotton grown in sodic soils are not a direct result of Na:Ca ratio in the soil solution.     

Longitudinal and lateral variations in the aluminum concentration of selected caprine, bovine, and human bone samples

Longitudinal and lateral variations in Al concentration in several large animal (bovine and caprine) long bones (tibia and femur) and several human clavicle bones were examined using a sensitive analytical method based on electrothermal atomization atomic absorption spectrometry with Zeeman background correction. Bone segments were carefully removed using special tools free of significant Al contamination, freeze-dried, and digested overnight at room temperature in concentrated HNO₃. Bone digestates were analyzed for Al using simple aqueous calibration standards with a Ca(NO₃)₂ modifier. Mean bone Al concentrations were relatively low (<1 Μg/g, dry weight) in bovine and caprine long bones compared to literature values for human bone samples. Longitudinal variations of Al in the animal bones examined appeared relatively uniform compared to the human clavicle bones, where, in three of five cases, Al appeared enriched at the epiphyses (joints). The Al “enrichment” was symmetrical with respect to both left and right clavicle bones. Aluminum concentrations at the mid-shaft of the clavicle bone show less variation compared to whole bone studies, but considerable scatter is evident along the bone length. The mean bone aluminum concentration in the five human subjects varied from 1 to 6 Μ/g dry weight.     

Serum zinc and somatic growth in children with growth retardation

A possible role for zinc deficiency in some cases of growth retardation in southern France was investigated. Control values for zinc for 160 children (age=12.5±2.4 yr) are 0.85±0.22 mg/L (mean ±2 SD). Twenty-five children with low serum zinc values (<0.63 mg/L) and 25 matched short children with normal serum zinc values (>0.63 mg/L) were studied. Children in the two groups did not differ significantly in age, pubertal development, stature, and weight. For the 25 children whose serum values were low, we found significantly lower values for bone age delay, growth velocity in mm/month, as well as the ratio between calculated growth velocity and theoretical growth velocity for the bone age (so that zincemia was correlated to these parameters in the whole sample of 50 subjects). Nevertheless, no significant difference could be found between the two groups for serum somatomedin C, serum osteocalcin values, and GH responses to the GH stimulatory tests (exercise test, overnight sampling, insulin-induced hypoglycemia, arginine test). Therefore, low serum zinc is associated with a retardation in both somatic growth and pubertal maturation.     

Intramembranaceous ossification analyses by a proton microprobe

The proton induced X-ray emission method in combination with a proton microprobe was applied to study the intramembranaceous ossification. As material sections of mouse embryo skulls from the 17th and 19th day of gestation were used. The morphology of the sample was examined by routine histochemical procedure performed on the sections adjacent to that irradiated by the proton microprobe. The measurements were made in line scan and raster scan mode. The concentrations of P, S, Cl, K, Ca, Fe and Zn were determined at each irradiated point. The average element concentrations were calculated for four parts of each section (bone, cartilage, mesenchymal tissue close to the bone and mesenchymal tissue in other places). The distributions of Ca and P (less markedly than Ca) concentrations almost exclusively correlate with localization of the bone while S, Cl and K concentrations show preference to the cartilage. The amount of inorganic material in flat bones of the 17-day embryo amounts to 14% of the dry mass. The material is characterized by a Ca/P ratio of about 1.6. In the embryo 2 days older the amount of the inorganic phase is practically the same (15%) while the Ca/P ratio approaches 2. This suggests the presence of the precursor phase in the flat bone calcification. It is possible that octacalcium phosphate (Ca/P ratio equals to 1.72) is formed at the onset of the flat bone mineralization which transforms rapidly (in 2 days) to a more stable mineral (defective hydroxyapatite).     

Intramembranaceous ossification analyses by a proton microprobe

Summary The proton induced X-ray emission method in combination with a proton microprobe was applied to study the intramembranaceous ossification. As material sections of mouse embryo skulls from the 17th and 19th day of gestation were used. The morphology of the sample was examined by routine histochemical procedure performed on the sections adjacent to that irradiated by the proton microprobe. The measurements were made in line scan and raster scan mode. The concentrations of P, S, Cl, K, Ca, Fe and Zn were determined at each irradiated point. The average element concentrations were calculated for four parts of each section (bone, cartilage, mesenchymal tissue close to the bone and mesenchymal tissue in other places). The distributions of Ca and P (less markedly than Ca) concentrations almost exclusively correlate with localization of the bone while S, Cl and K concentrations show preference to the cartilage. The amount of inorganic material in flat bones of the 17-day embryo amounts to 14% of the dry mass. The material is characterized by a Ca/P ratio of bout 1.6 In the embryo 2 days older the amount of the inorganic phase is practically the same (15%) while the Ca/P ratio approaches 2. This suggests the presence of the precursor phase in the flat bone calcification. It is possible that octacalcium phosphate (Ca/P ratio equals to 1.72) is formed at the onset of the flat bone mineralization which transforms rapidly (in 2 days) to a more stable mineral (defective hydroxyapatite).     

Seasonal changes in serum dehydroepiandrosterone,androstenedione, and testosterone levels in the squirrel monkey (Saimiri boliviensis boliviensis)

The squirrel monkey (Saimiri boliviensis boliviensis) has a well-defined breeding season during which adult males undergo androgen-dependent morphological changes, with acquisition of active spermatogenesis. To assess the hormonal events of this annual cycle, blood samples were obtained weekly from ten adult males, and serum was assayed for testosterone (T), androstenedione (ΔA), and dehydroepiandrosterone (DHEA). A significant seasonal variation was noted in mean serum T (P < 0.02), ΔA (P < 0.02), and DHEA (P < 0.001) concentrations. Mean ΔA concentrations increased from a nonbreeding season nadir of 91.4 ± 12.9 ng/ml (mean ± standard error) to a prebreeding concentration of 139 ± 10.5 ng/ml and breeding season peak of 167.5 ± 15.4 ng/ml (P < 0.05). Mean DHEA concentrations increased from a nonbreeding season nadir of 8.3 ± 0.8 to a breeding season peak of 14.3 ± 1.2 (P < 0.001). Mean T levels in the nonbreeding (52.2 ± 11.6 ng/ ml) and prebreeding season (48.6 ± 7.4) were similar. However, T significantly increased during the breeding season to 103.5 ± 12.8 ng/ml (P < 0.05). Progressive changes in body weight and morphology paralleled the rise in serum ΔA levels. The pattern of peripheral serum androgen concentrations throughout the year would suggest annual activation of the hypothalamic-pituitary-adrenal and/or hypothalamic-pituitary-gonadal axes.