Genetic and Environmental Correlations between Bone Geometric Parameters and Body Compositions

The purpose of this study was to determine the genetic and environmental correlations between weight, lean mass and bone geometric parameters (sub-periosteal diameter, W; cross-sectional area, CSA; cortical thickness, CT; section modulus, Z; and buckling ratio, BR) of femoral neck. The sample was composed of 512 Caucasian pedigrees, including 2667 females and 1822 males. Bivariate quantitative genetic analyses were performed to evaluate the genetic (ρ _G ), environmental (ρ _E ) and phenotypic (ρ _P ) correlations between the study traits. Univariate genetic analyses showed that the heritabilities (h ²) for bone geometric parameters were significant (P < 0.001) ranging from 0.50 to 0.60. The significant common household effects indicated the common environment shared by household members for W, CSA, CT, Z and BR (P < 0.05), but the magnitude was small compared with heritabilities. ρ _E , ρ _G and ρ _P between bone geometric parameters and weight, lean mass were generally significant. Interestingly, lean mass showed both stronger genetic and environmental correlations with the bone geometric parameters than weight. In addition, according to the magnitude of correlation coefficients, the ρ _G between body compositions and bone geometric parameters were generally stronger thanρ _E (except for that between BR and body compositions). These data suggested that the geometric parameters of femoral neck are under strong genetic control. Furthermore, some common genetic and environmental factors are shared by bone geometric parameters and weight, lean mass. The results may help understand the intertwined relationships between bone metabolisms, mechanical loading and body compositions. Xiao Sun and Shu-Feng Lei contribute equally to this work     

Femoral neck geometry in overweight and normal weight adolescent girls

Being overweight is associated with increased bone mineral content, bone mineral density (BMD), and bone strength in adults. However, the effect of being overweight on bone strength during adolescence is poorly understood. The aim of this study was to compare femoral neck geometry in overweight and normal weight adolescent girls. This study included 22 overweight (BMI > 25 kg/m²) adolescent girls (15.4 ± 2.4 years old) and 20 maturation-matched (15.2 ± 1.9 years old) controls (BMI < 25 kg/m²). Body composition and BMD were assessed by dual-energy X-ray absorptiometry (DXA). To evaluate bone geometry, DXA scans were analyzed at the femoral neck by the hip structure analysis (HSA) program. Cross-sectional area (CSA), an index of axial compression strength, section modulus (Z), an index of bending strength, cross-sectional moment of inertia (CSMI), cortical thickness (CT), and buckling ratio (BR) were measured from bone mass profiles. Lean mass, body weight, fat mass, and BMI were higher in overweight girls compared to controls (P < 0.001). CSA, Z, and CSMI were higher in overweight girls compared to controls (P < 0.05; P < 0.01 and P < 0.01, respectively). CT and BR were not significantly different between the two groups. After adjustment for body weight, lean mass, or fat mass, using a one-way analysis of covariance (ANCOVA), there were no differences between the two groups (overweight and controls) regarding the HSA variables (CSA, Z, CSMI, CT, and BR). In conclusion, this study suggests that overweight adolescent girls have greater indices of bone axial and bending strength in comparison to controls at the femoral neck.     

Hip bone strength indices in overweight and control adolescent boys

The influence of being overweight on bone strength in adolescents remains controversial. The aim of this study was to compare hip bone strength indices in overweight and control adolescent boys using hip structure analysis (HSA). This study included 25 overweight adolescent boys [body mass index (BMI) >25 kg/m²] and 31 maturation-matched controls (BMI <25 kg/m²). Body composition and bone mineral density were assessed by dual-energy X-ray absorptiometry (DXA). To evaluate hip bone strength, DXA scans were analyzed at femoral neck, intertrochanteric, and femoral shaft by the HSA program. Cross-sectional area (CSA), an index of axial compression strength, section modulus (Z), an index of bending strength, cross-sectional moment of inertia (CSMI), cortical thickness (CT), and buckling ratio (BR) were measured from bone mass profiles. Body weight, lean mass, fat mass, and BMI were higher in overweight boys compared to controls (P < 0.001). CSA, CSMI, and Z of the three sites (femoral neck, intertrochanteric, and femoral shaft) were higher in overweight boys compared to controls (P < 0.01). BR was not significantly different between the two groups at the three sites. After adjustment for either body weight, BMI, or fat mass, using a one-way analysis of covariance, there were no differences between the two groups regarding the HSA variables (CSA, Z, CSMI, CT, and BR). After adjusting for lean mass, overweight boys displayed higher values of femoral shaft CSA, CSMI, and Z in comparison to controls (P < 0.05). In conclusion, this study suggests that overweight adolescent boys have greater indices of bone axial and bending strength in comparison to controls at the femoral neck, the intertrochanteric, and the femoral shaft.     

Genome-wide copy number variation association study suggested VPS13B gene for osteoporosis in Caucasians

Summary

Osteoporotic fracture (OF) is a serious outcome of osteoporosis. Important risk factors for OF include reduced bone mineral density and unstable bone structure. This genome-wide copy number variation association study suggested VPS13B gene for osteoporosis in Caucasians.

Introduction

Bone mineral density (BMD) and femoral neck cross-sectional geometric parameters (FNCSGPs) are under strong genetic control. DNA copy number variation (CNV) is an important source of genetic diversity for human diseases. This study aims to identify CNVs associated with BMD and FNCSGPs.

Methods

Genome-wide CNV association analyses were conducted in 1,000 unrelated Caucasian subjects for BMD at the spine, hip, femoral neck, and for three FNCSGPs —cortical thickness (CT), cross-section area (CSA), and buckling ratio (BR). BMD was measured by dual energy X-ray absorptiometry (DEXA). CT, CSA, and BR were estimated using DEXA measurements. Affymetrix 500K arrays and copy number analysis tool was used to identify CNVs.

Results

A CNV in VPS13B gene was significantly associated with spine, hip and FN BMDs, and CT, CSA, and BR (p?<?0.05). Compared to subjects with two copies of the CNV, carriers of one copy had an average of 14.6%, 12.4%, and 13.6% higher spine, hip, and FN BMD, 20.0% thicker CT, 10.6% larger CSA, and 12.4% lower BR. Thus, a decrease of the CNV consistently produced stronger bone, thereby reducing osteoporotic fracture risk.

Conclusions

VPS13B gene, via affecting BMD and FNCSGPs, is a novel osteoporosis risk gene.     

Genetic determination and correlation of body mass index and bone mineral density at the spine and hip in Chinese Han ethnicity

The purpose of the present study was to evaluate the magnitude of genetic determination of spine and hip bone mineral density (BMD) and body mass index (BMI), and to explore the genetic, environmental, and phenotypic correlations among the above phenotypes in Chinese Han ethnicity. The sample was composed of at least 217 complete nuclear families in Chinese Han ethnicity. BMD at the spine and hip was measured using a dual-energy X-ray absorptiometry scanner. The heritability ( h ²) of BMI and BMD at the spine and hip, the genetic correlation ( _G ) and environmental correlation ( _E ) among the three phenotypes were evaluated via variance analysis, with age, sex, and age-by-sex interaction as covariates. The phenotypic correlation ( _P ) and the bivariate heritability _G² were also calculated. The heritability for BMD and BMI was ~0.70 and ~0.50, respectively ( p <0.0001). The common environment shared by household members (household effect) is significant for BMI variation ( p =0.0004). Significant genetic, environmental, and phenotypic correlation was observed. The _G² values were 0.13 for BMI/spine BMD, 0.18 for BMI/hip BMD, and 0.58 for the spine BMD/hip BMD. While BMD at the spine and hip have significant genetic determination, BMI is more likely to be affected by environmental factors than BMD. In addition, BMD at the spine and hip shares more genetic effect (pleiotropy) than BMI and BMD do in Chinese Han ethnicity, though the effects are significant for both.     

Bivariate Linkage Study of Proximal Hip Geometry and Body Size Indices: The Framingham Study

Femoral geometry and body size are both characterized by substantial heritability. The purpose of this study was to discern whether hip geometry and body size (height and body mass index, BMI) share quantitative trait loci (QTL). Dual-energy X-ray absorptiometric scans of the proximal femur from 1,473 members in 323 pedigrees (ages 31–96 years) from the Framingham Osteoporosis Study were studied. We measured femoral neck length, neck-shaft angle, subperiosteal width (outer diameter), cross-sectional bone area, and section modulus, at the narrowest section of the femoral neck (NN), intertrochanteric (IT), and femoral shaft (S) regions. In variance component analyses, genetic correlations (ρ _G ) between hip geometry traits and height ranged 0.30–0.59 and between hip geometry and BMI ranged 0.11–0.47. In a genomewide linkage scan with 636 markers, we obtained nominally suggestive linkages (bivariate LOD scores ≥1.9) for geometric traits and either height or BMI at several chromosomes (4, 6, 9, 15, and 21). Two loci, on chr. 2 (80 cM, BMI/shaft section modulus) and chr. X (height/shaft outer diameter), yielded bivariate LOD scores ≥3.0; although these loci were linked in univariate analyses with a geometric trait, neither was linked with either height or BMI. In conclusion, substantial genetic correlations were found between the femoral geometric traits, height and BMI. Linkage signals from bivariate linkage analyses of bone geometric indices and body size were similar to those obtained in univariate linkage analyses of femoral geometric traits, suggesting that most of the detected QTL primarily influence geometry of the hip.     

Anthropometric predictors of geometric indices of hip bone strength in a group of Lebanese postmenopausal women

The effects of anthropometric characteristics on hip bone strength in postmenopausal women are not completely elucidated. The aim of this study was to investigate the influence of anthropometric characteristics on geometric indices of hip bone strength using the hip structure analysis (HSA) program in a group of Lebanese postmenopausal women. This study included 109 postmenopausal women (aged 64--84yr). Age and years since menopause were recorded. Body composition and bone mineral density were assessed by dual-energy X-ray absorptiometry (DXA). To evaluate hip bone strength, DXA scans were analyzed at the femoral neck (FN), the intertrochanteric (IT), and the femoral shaft (FS) by the HSA program. Cross-sectional area (CSA), an index of axial compression strength, section modulus (Z), an index of bending strength, and buckling ratio (BR), an estimate of cortical stability in buckling, were measured from bone mass profiles. Using univariate analysis, weight, height, body mass index (BMI), lean mass, and fat mass were positively correlated to CSA and Z of the FN, IT, and FS. Weight, BMI, fat mass, and fat mass percentage were negatively correlated to BR of the FN, IT, and FS. Multiple linear regression analysis showed that lean mass was a stronger determinant of FN CSA, FN Z, IT Z, and FS Z than fat mass, whereas fat mass was a stronger determinant of IT CSA, FS CSA, IT BR, and FS BR than lean mass. This study suggests that, in postmenopausal women, fat mass is a strong predictor of hip axial compression strength and cortical stability in buckling, and lean mass is a strong predictor of hip bending strength.     

Association of Body Composition and Physical Activity with Proximal Femur Geometry in Middle-Aged and Elderly Afro-Caribbean Men:

Osteoporotic fractures are less prevalent in African Americans than in caucasians, possibly because of differences in bone structural strength. Bone structural adaptation can be attributed to changes in load, crudely measured as lean and fat mass throughout life. The purpose of this analysis was to describe the associations of leg lean mass, total body fat mass, and hours walked per week with femoral bone mineral density (BMD) and bone geometry in a cross-sectional sample of 1,748 men of African descent between the ages of 40 and 79 years. BMD, section modulus (Z), cross-sectional area (CSA), and subperiosteal width were measured from dual energy X-ray absortiometry (DXA) scans using the hip structural analysis (HSA) program. Multiple linear regression models explained 35% to 48% of the variance in bending (Z) and axial (CSA) strength at the femoral neck and shaft. Independent of all covariates including total body fat mass, one standard deviation increase in leg lean mass was significantly associated with a 5% to 8% higher Z, CSA, and BMD (P < 0.010) at the neck and shaft. The number of hours walked per week was not a strong or consistent independent predictor of bone geometry or BMD. We have shown that weight is the strongest independent predictor of femur BMD and geometric strength although the effect appears to be mediated by lean mass since leg lean mass fraction and total body fat mass fraction had significant and opposing effects at the narrow neck and shaft in this group of middle aged and elderly men.     

Transmission electron microscopy of lattice planes in human alveolar bone apatite crystals

Summary Periodic fringes corresponding to six different lattice planes have been observed in apatite crystals of human normal alveolar bone by transmission electron microscopy. Three of these sets of fringes have spacings less than 3.5 ? corresponding to the Scherzer resolution of the microscope used. The (0002) lattice plane of hydroxyapatite of 3.4 ? d-spacings, the lattice plane with a d-spacing of 2.81 ?, and the lattice plane with a d-spacing of 2.72 ? have been identified. The (0002) and lattice planes have been observed for the first time in bone microcrystals. Some of the crystals studied were characterized by a mean width/thickness ratio of 6.91, typical of platelike habit, whereas observations of crystals aligned along the and directions showed a needlelike habit. The mean length of the bone apatite crystals was 470 ?. A dark line similar to the one observed in enamel and dentine crystals was also seen. The bone microcrystals observed have shown a high sensitivity to beam damage.     

Gradient of bronchial end-tidal CO2 during two-lung ventilation in lateral decubitus position is predictive of oxygenation disorder during subsequent one-lung ventilation

Purpose  Hypoxemia is one of the major problems during one-lung ventilation (OLV). During two-lung ventilation (TLV) using a double-lumen bronchial tube, bronchial endtidal carbon dioxide partial pressure () can be determined on both sides, independently. The is mainly dependent on the pulmonary perfusion to each lung. If the degree of oxygenation disorder during OLV were to be predictable before starting OLV, this could provide time to prepare for any subsequent hypoxemia. The aim of this study was to investigate whether the difference of (D-) between the dependent and the nondependent lungs during TLV in the lateral decubitus position (LP) could be a predictive factor for the severity of oxygenation disorder under subsequent OLV. Methods  Eighteen patients undergoing lung surgery were enrolled in this study. Anesthesia was induced with intravenous thiopental and fentanyl, supplemented by the inhalation of sevoflurane. A left-sided double-lumen bronchial tube was placed. The was independently determined on each side during TLV in the supine position (SP) and at 10 min after changing the position from SP to LP. / inspiratory fraction of oxygen () was taken at 15 min after switching from TLV to OLV in LP. Results  The decrease of / at 15 min during OLV in LP correlated with the reduction of the D- predetermined during TLV in LP (r = 0.698; P < 0.01). Conclusion  The D- predetermined during TLV in LP could be a predictive factor for the severity of oxygenation disorder after starting OLV in LP.     

An analysis of CO2 elimination curves during artificial ventilation

We have developed some indices to evaluate the phase III slope in CO₂ elimination curves. The indices were applied to 12 mechanically ventilated patients in ICU to determine their stability under various ventilator settings. F_co2-sl[30–90] and expressed the mean incline of phase III slope in F_co2-volume curves and -volume curves, respectively. F_co2-SR and -SR expressed the ratio of the slopes in the first and second halves of the phase III portion in both curves. The indices were also applied to 108 elective surgery patients to determine their usefulness in predicting ventilatory efficiency during general anesthesia. In the first study, F_co2-sl[30–90] and [30–90] correlated with ET_co2, V_d/V_t and the volume of CO₂ expired, but F_co2-SR and -SR were independent of these parameters. -SR did not show any significant changes under various ventilator settings except for application of PEEP. In the second study, those with impaired preoperative respiratory function had significantly larger values for . was as sensitive as parameters such as V_D/V_T, arterial to end-tidal CO₂ tension difference (a-ET·D_co2), and volume pressure index (VPI) in prediting poor respiratory functions. We concluded that is a useful index for evaluating the phase III slope in CO₂ elimination curves.     

Studies on fluorapatite

A mineral specimen from Burgess, Canada, proved upon chemical and crystallographic analyses to be an exceptionally pure sample of fluorapatite. The over-all composition corresponds to $$(Ca^{2 + } )_{9.98} (Sr^{2 + } ,Na^ + ,K^ + ,Mg^{2 + } )_{0.02} (PO_4^{3 - } )_{5.98} (HCO_3^ - ,CO_3^{2 - } )_{0.02} (F^ - )_2 $$ . The crystallographic c-axis was determined to be 6.865 Å, and the a-axis 9.374 A. Exchange data obtained by employing⁴⁵Ca,³²P, and¹⁸F indicate the presence of large crystallites with a specific surface of the order of 1 m²/g. It is indicated that the physical interpretation of the exchange process does not require the existence of separate departments, each with its own kinetic factor, but that the exchange may be simply related to the exponential change in the free energy of the reaction. For the reaction $$(Ca)_5 (PO_4 )_3 OH_{solid} + (F^ - ) \rightleftarrows (Ca)_5 (PO_4 )_3 F_{solid} + (OH^ - )$$ the thermodynamic constant has been calculated to be 10^1.26, implying that fluorapatite always will form at the expense of hydroxyapatite under physiologic conditions. This transformation will be furthered by lowering the pH.     

Relationship between body composition and bone mineral density in healthy young and premenopausal Chinese women

This study investigated the relative contribution of fat mass and lean mass to bone mineral density (BMD) in young and premenopausal healthy Chinese women. The study was performed in 282 young and premenopausal healthy women with regular menstrual cycles. The BMD at lumbar spine (L2–L4), total hip and total body, together with fat mass and lean mass were assessed by dual-energy X-ray absorptiometry (DXA); body height, weight, waist and hip circumference were also measured, and body mass index (BMI) and waist-hip ratio were calculated. Fat mass was a major determinant for BMI, BMI and lean mass were positively related to L2–L4, total hip and total body bone density (P<0.001 for all), lean mass was the only independent factor contributing to BMD at L2–L4 (standardized coefficient =0.282, P<0.001), total hip (=0.336, P<0.001) and total body (=0.361, P<0.001) in multiple stepwise regression analysis. The correlation between BMI and BMD was improved after adjustment for fat mass, while decreased or even lost when lean mass was adjusted. These data suggested that in the Chinese population, lean mass is an important factor determining BMD in young and premenopausal women.     

NOx (nitrite/nitrate) in patients with pediatric nephrotic syndrome

To better understand the role of nitric oxide (NO) in pediatric nephrotic syndrome, we measured nitrite/nitrate (NOx) in serum obtained from patients with several pediatric kidney diseases and investigated the locations of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS). NOx in serum showed significantly higher levels than those in healthy controls (mean ± SE: 297 ± 55.7 vs. 158 ± 13.1 pmol/10 μl). There was no significant difference between six patients with frequent relapse and five patients with nonfrequent relapse. The studies with immunostaining of iNOS and nitrotyrosine were negative for glomerulus in patients with nephrotic syndrome. Those findings suggest that NOx might indirectly influence disease progression in nephrotic syndrome.     

Proximal femur bone geometry is appropriately adapted to lean mass in overweight children and adolescents

It is unclear if the bones of overweight children are appropriately adapted to increased loads. The objective of this study was to compare bone geometry in 40 overweight (body mass index [BMI] > 85th percentile) and 94 healthy weight (BMI < or = 85th percentile) subjects, ages 4-20 years. Dual energy X-ray absorptiometry (Hologic QDR 2000) scans were analyzed at the femoral shaft (FS) and narrow neck (NN) by the Hip Structure Analysis program. Subperiosteal width, cortical thickness and indices of bone axial and bending strength (bone cross-sectional area [CSA] and section modulus [Z]) were measured from bone mass profiles. Multivariate regression models were used to compare overweight and healthy weight subjects. Z was 11 (95% CI 5, 19) and 13 (7, 20) percent higher at the FS and NN, respectively, in overweight subjects (P < 0.001), adjusted for height, maturation and gender. At the NN, higher Z was due to greater subperiosteal width [4% (2, 7)] and bone CSA [10% (5, 16]) and at the FS, to higher bone CSA [10% (5, 16)] and thicker cortices [9% (3, 15)]. When lean mass was added to the models, bone variables did not differ between overweight and healthy weight subjects (P > 0.22), with the exception of NN subperiosteal width [3% (0, 6), P = 0.04]. Fat mass did not contribute significantly to any model. In summary, proximal femur bone geometric strength in overweight children was appropriately adapted to lean mass and height but greater weight in the form of fat mass did not have an independent effect on bone bending strength. These geometric adaptations are consistent with the mechanostat hypothesis that bone strength adapts primarily to muscle forces, not to static loads represented by body weight.     

Hyperventilation versus standard ventilation for infants in postoperative care for congenital heart defects with pulmonary hypertension

Purpose  In infants undergoing surgery for cardiac defects with left-to-right shunt, a hyperventilation strategy has been applied to prevent pulmonary hypertensive crisis (PHC). Hyperventilation with a large tidal volume and/or higher airway pressure, however, may be detrimental to the lung. This randomized study compared the effects of hyperventilation versus standard ventilation. Methods  We enrolled 22 infants with a preoperative pulmonary-to-systemic blood pressure ratio of more than 0.7. Hyperventilation, with a tidal volume of 10–12 ml·kg⁻¹ to keep between 30 and 35 mmHg, was randomly applied in 11 patients for 16 h or more. The other 11 patients were randomly assigned to standard ventilation, with a 6- to 8- ml·kg⁻¹ tidal volume. Results  The peak inspiratory pressure was higher (20 ± 3 vs 18 ± 2 cmH₂O; P = 0.018), and (34 ± 5 vs 42 ± 7 mmHg; P = 0.003) and positive end-expiratory pressure (3 ± 0 vs 5 ± 0; P < 0.0001) were significantly lower in the hyperventilation than in the standard ventilation group. The /inspiratory fraction of oxygen ratio decreased from 244 ± 160 mmHg at the onset of postoperative ventilation, to 177 ± 96 mmHg at 24 h (P = 0.038) in the hyperventilation group, versus a decrease from 240 ± 89 to 220 ± 97 mmHg in the standard ventilation group not significant (NS). Serum interleukin (IL)-6 level, measured at 24 h postoperatively, was significantly lower (P = 0.02) in the standard ventilation than in the hyperventilation group, suggesting an attenuated postoperative systemic inflammatory response. A single patient in each group developed PHC. Conclusion  Hyperventilation may cause lung injury and systemic inflammation in infants with pulmonary hypertension undergoing corrective heart surgery. T. Umenai and N. Shime contributed equally to this study.     

The effects of once-weekly teriparatide on hip structure and biomechanical properties assessed by CT

Summary

Once-weekly administration of 56.5 μg teriparatide improved cortical bone parameters and biomechanical parameters at the proximal femur by CT geometry analysis.

Introduction

The aim of this study was to evaluate the effects of weekly administration of teriparatide [human PTH (1–34)] on bone geometry, volumetric bone mineral density (vBMD), and parameters of bone strength at the proximal femur which were longitudinally investigated using computed tomography (CT).

Methods

The subjects were a subgroup of a recent, randomly assigned, double-blind study (578 subjects) comparing the anti-fracture efficacy of a once-weekly subcutaneous injection of 56.5 μg teriparatide with placebo (TOWER trial).

Results

Sixty-six ambulatory postmenopausal women with osteoporosis were enrolled at 15 study sites having multi-detector row CT, and included women injected with teriparatide (n?=?29, 74.2?±?5.1 years) or with placebo (n?=?37, 74.8?±?5.3 years). CT data were obtained at baseline and follow-up scans were performed at 48 and 72 weeks. The data were analyzed to obtain cross-sectional densitometric, geometric, and biomechanical parameters including the section modulus (SM) and buckling ratio (BR) of the femoral neck, inter-trochanter, and femoral shaft. We found that once-weekly teriparatide increased cortical thickness/cross-sectional area (CSA) and total area, and improved biomechanical properties (i.e., decreasing BR) at the femoral neck and shaft. Teriparatide did not change the cortical perimeter.

Conclusions

Our longitudinal analysis of proximal femur geometry by CT revealed that once-weekly administration of 56.5 μg teriparatide improved cortical bone parameters at the femoral neck and shaft and also improved biomechanical parameters.     

A neutrophil elastase inhibitor,sivelestat, improved respiratory and cardiac function in pediatric cardiovascular surgery with cardiopulmonary bypass

Purpose  Several reports indicate that a neutrophil elastase inhibitor, sivelestat, may have prophylactic efficacy against a systemic inflammatory response after cardiovascular surgery with cardiopulmonary bypass (CPB). We evaluated the clinical pulmonary and cardiac effects of sivelestat. Methods  We performed a retrospective study of 25 pediatric patients who underwent elective cardiovascular surgery with CPB for ventricular septal defect with pulmonary hypertension. Ten patients received 0.2 mg·kg⁻¹·h⁻¹ sivelestat; the other is patients were the control group. There were no significant differences in demographic characteristics between the two groups. The /fractional inspired oxygen (; P/F) ratio, the respiratory index (RI), and the fractional area change (FAC) of the left ventricle (LV) in the postoperative course were measured. Results  The P/F ratio was higher in the sivelestat group compared with the control group and there were significant differences between the two groups immediately after weaning form CPB, and at 12 h after weaning from CPB (P < 0.05). The RI was lower in the sivelestat group compared with the control group and there were significant differences between the two groups at immediately after weaning from CPB, and at 6 h and 12 h after CPB (P < 0.05). The FAC of the LV was significantly better in the sivelestat group and there was a significant difference between the two groups on postoperative day (POD) 3 (P < 0.05). Conclusion  We have shown that pediatric patients who underwent cardiovascular surgery with CPB who received sivelestat had a higher P/F ratio, a lower RI, and better FAC of the LV in the postoperative course.     

Fourier transform raman spectroscopy of synthetic and biological calcium phosphates

Fourier-transform (FT) Raman spectroscopy was used to characterize the organic and mineral components of biological and synthetic calcium phosphate minerals. Raman spectroscopy provides information on biological minerals that is complimentary to more widely used infrared methodologies as some infrared-inactive vibrational modes are Raman-active. The application of FT-Raman technology has, for the first time, enabled the problems of high sample fluorescence and low signal-to-noise that are inherent in calcified tissues to be overcome. Raman spectra of calcium phosphates are dominated by a very strong band near 960 cm^–1 that arises from the symmetric stretching mode of the phosphate group. Other Raman-active phosphate vibrational bands are seen at approximately 1075 , 590 , and 435 cm^–1 . Minerals containing acidic phosphate groups show additional vibrational modes. The different calcium phosphate mineral phases can be distinguished from one another by the relative positions and shapes of these bands in the Raman spectra. FT-Raman spectra of nascent, nonmineralized matrix vesicles (MV) show a distinct absence of the phosphate band even though these structures are rich in calcium and phosphate. Similar results were seen with milk casein and synthetic Ca-phosphatidyl-serine-PO₄ complexes. Hence, the phosphate and/or acidic phosphate ions in these noncrystalline biological calcium phosphates is in a molecular environment that differs from that in synthetic amorphous calcium phosphate. In MV, the first distinct mineral phase to form contained acidic phosphate bands similar to those seen in octacalcium phosphate. The mineral phase present in fully mineralized MV was much more apatitic, resembling that found in bones and teeth. These findings are consistent with formation of an OCP-like precursor during MV mineral formation that subsequently hydrolyzes to form hydroxyapatite.     

Bone cross-sectional geometry in adolescents and young women with anorexia nervosa: a hip structural analysis study

Introduction Better characterization of bone geometry in adolescents with anorexia nervosa (AN) may improve understanding of skeletal deficits in this population. Our objective was to determine whether hip cross-sectional geometry and bone strength were altered in adolescents with AN. Methods Measurements of the left total proximal femur and body composition were obtained in 85 adolescents with AN and 61 healthy controls by dual X-ray absorptiometry. The Hip Structural Analysis (HSA) program was used to determine aBMD, cross-sectional area (CSA), and section modulus (Z) at the femoral neck and shaft. Strength indices were calculated and corrected for lean mass. Results Femoral neck and shaft aBMD were lower in AN patients than healthy controls (−36% and −29%, p < 0.001). In both regions, bone CSA and Z were lower in AN sufferers (−11 to −35%, p < 0.001). While lean body mass correlated with HSA variables (r = 0.48 to 0.58, p < 0.001), body fat did not. AN sufferers had lower indices of both whole bone strength (−40%, p < 0.001) and relative bone strength (−36%, p < 0.001) than controls. Conclusions Anorexia nervosa sufferers had decreased resistance to axial (CSA) and bending loads (Z) compared with healthy controls. Differences in strength properties were significant even when adjusted for lean mass, suggesting that not only decreased mechanical loading, but also known metabolic differences are likely responsible for deficits in bone strength in these patients.