qMRI relaxometry of mandibular bone marrow: A monomodal distribution in sickle cell disease

Purpose:

To identify and characterize sickle cell disease (SCD)‐related changes in the composition of mandibular bone marrow using qMRI relaxometry histograms.

Materials and Methods:

Thirteen SCD patients and 17 controls underwent brain MR imaging with the mixed turbo spin‐echo (TSE) pulse sequence at 1.5T. The mandible was manually segmented and divided into body, angle, ramus, and condyle. T1 and T2 histograms of each mandible were modeled with Gaussian functions. The relaxation time histogram peaks were calculated, and the number of monomodal versus bimodal curves was compared.

Results:

SCD patients exhibited monomodal distributions on both T1 and T2 histograms, consistent with a composition of predominantly red hematopoietic marrow. Eighty‐eight percent of mandibles in control subjects exhibited a bimodal distribution in T1 and all showed a bimodal distribution in T2, indicating mixed but predominantly yellow marrow composition. The second peak in control subjects was shorter in T1 and longer in T2, consistent with yellow marrow composition.

Conclusion:

Instead of physiological fatty replacement, SCD patients exhibit red marrow persistence in the mandible, likely due to the increased demand for hematopoiesis. This phenomenon can be manifested by a monomodal curve in both T1 and T2 relaxometric histograms. J. Magn. Reson. Imaging 2013;37:1182–1188. © 2012 Wiley Periodicals, Inc.     

Effect of 1α-Hydroxyvitamin D3 on Cancellous Bone Matrix: An Experimental Study on Adult Rats

Two groups of adult male rats were treated perorally for 6 weeks with 0.1 μg and 1.0 μg of 1a-hydroxyvitamin D₃ (la-OH-D₃), respectively. The effect of the treatment on cancellous bone matrix was studied by chemical analysis and morphometric measurements. The effect of the 1.0 μg dose on the inorganic composition, and on the calcification of the cancellous bone matrix, was significantly more pronounced, decreasing the amount of glycosaminoglycans. The lower dose level, 0.1 μg of la-OH-D₃, increased the collagen metabolism, whereas the higher dose level did not. The amount of cancellous bone determined morphometrically increased significantly during treatment with both dose levels. 1a-OH-D₃, converted in the organism to the hormonal form 1.25 (OH)₂D₃, induces new bone formation, probably by direct influence on the cancellous bone tissue itself.     

Effects of air tourniquet on the antibiotics concentration,in bone marrow,injected just before the start of operation

Abstract

Infection is one of the most serious complications after artificial arthroplasty. In order to establish the effective prevention for after operative infection, we measured the serum and bone marrow blood cefmetazole (CMZ) concentration time dependently (1?g CMZ, one shot). Furthermore, we studied the effect of air tourniquet on CMZ transmit into bone marrow blood. Thirteen knees with total knee arthroplasty (TKA) were included in the study. As a control group, 11 hips with total hip arthroplasty (THA) were also included. In TKA, air tourniquet was used during operation in all cases. Just before the start of the operation, 1?g CMZ was injected intravenously (one shot). Subsequently we sampled peripheral blood and bone marrow blood time dependently. Cefmetazole concentration was measured with HPLC. In the THA group, serum and bone marrow blood CMZ concentration showed almost the same time-dependent change. On the other hand, in the TKA group we could not detect CMZ in bone marrow blood in cases where CMZ was injected within 8?min before starting use of an air tourniquet. If CMZ was injected more than 10?min before starting use of the air tourniquet, CMZ concentration in bone marrow blood was much lower than minimum inhibitory concentration (MIC) for Staphylococcus aureus; but after releasing the air tourniquet, CMZ concentration in bone marrow blood was higher than MIC for S. aureus. These data suggested that our injection method is effective for prevention of infection both during and just after operation in the THA but in the TKA, CMZ should be injected more than 10?min before starting to use the air tourniquet.     

喷射心肌打孔移植骨髓间充质干细胞治疗心肌梗塞的实验研究

【摘要】 目的 探讨喷射心肌打孔移植骨髓间充质干细胞治疗缺血性心脏病的可行性。方法 将32只健康杂种犬随机分为单纯建模组（MI组），无针喷射生理盐水组（NS组），有针注射移植干细胞组（N+MSCs组），无针喷射移植干细胞组（NF+MSCs组）每组8只犬；建立急性心梗模型，分别采用直接关胸、无针喷射生理盐水、有针注射移植干细胞和无针喷射移植干细胞于梗死区进行操作。术后6周处死动物并检测血流动力学，取材行大体及组织学观察，计算心肌梗死面积及新生血管计数。结果 较其他组比较，NF+MSCs组左室舒张末压(900±32mmHg)下降、左室内压最大上升(84186±7285 mmHg/s)和下降速率( 78729±4508 mmHg/s)升高、梗死面积(1859±358%)缩小、新生小血管数量(957±223)增多（P＜005）。结论 喷射心肌打孔移植干细胞治疗缺血性心脏病是安全、有效的，可为临床研究提供参改。     

The effect of pentoxifylline on the flow properties of human blood

Summary

Recent investigations have revealed that erythrocytes from patients with chronic arterial occlusive disease are significantly less deformable than red blood cells from healthy subjects. The influence of pentoxifylline on red blood cell fluidity was measured by a standard filtration technique using 8 μm membrane filters. Impaired deformability of erythrocytes was significantly improved in patients suffering from peripheral vascular disorders following intravenous injection of 200?mg pentoxifylline. Studies on reduced red cell deformability induced by hyperosmolarity in vitro showed that pentoxifylline (4 and 20 μg/ml) produced a dose-dependent improvement both in blood from healthy subjects and from patients with peripheral arterial occlusive disease. The results suggest that the positive therapeutic effect of pentoxifylline in peripheral arterial occlusive disease is mediated by improving red cell fluidity in the microcirculation.     

The impact of proton pump inhibitors on bone regeneration and implant osseointegration

Abstract

Proton pump inhibitors (PPIs) have become known for the treatment of gastric-acid related disorders. Similar to any other drugs, PPIs have possible adverse reactions, being associated with bone fractures, infections, kidney disease, mineral deficiency, dementia, and pneumonia. Multiple analyses have stated that PPIs therapy may affect bone regeneration and osseointegration process, causing an increased risk of bone fracture, deterioration of bone metabolism and impaired bone healing. In this review, we emphasized the current literature regarding the influence of proton pump inhibitors in the bone regeneration process. Results from the studies suggest a link between PPIs intake and bone regeneration, but several concerns are raised regarding inadequate recipient bone, surgical trauma, limitations on the titanium surface, comorbidities or interference with other pharmacological agents. Further studies are needed to determine whether the impaired bone regeneration process is due to PPI or coexisting factors.     

Book review of Child and adolescent obesity: Causes and consequences,prevention and management. Edited by W. Burniat,T. J. Cole,I. Lissau and E. M. E. Poskitt. (Cambridge University Press,Cambridge, 2002). [pp. 436]. ISBN: 0521 652375. £70.00 hbk.

Background: Bone mineral density (BMD), bone mineral content (BMC), and bone size have been widely studied individually as important risk factors for osteoporotic fracture, but little is known about the correlation and the degree of sharing genetic and environmental factors between the pairs of the three phenotypes.

Aim: The study investigated genetic correlation (ρ_G), environmental correlation (ρ_E) and phenotypic correlation (ρ_P) between BMD, BMC and bone size.

Subjects and methods: Bivariate variance decomposition analyses were performed in 904 subjects from 287 Chinese nuclear families.

Results: Significant ρ_E, ρ_G and ρ_P were detected between BMD, BMC and bone size, except for ρ_E between BMD and bone size at the hip (ρ_E?=?0.121, p?=?0.361). Common shared genetic factors explained 86.1% and 60% of BMD and BMC genetic variations at the spine and hip, respectively. However, the genetic and environmental correlations between BMD and bone size were limited. ρ_E and ρ_G at the spine were 0.392 and 0.381, and at the hip were 0.121 and ?0.205, respectively. Only 14.5% and 4.2% of variations between BMD and bone size at the spine and hip may be due to the shared genetic factors.

Conclusion: The obtained results suggested that bone size may be used as another surrogate phenotype independently of BMD for eventual elucidation of the pathogenesis of osteoporosis because of the limited correlations between BMD and bone size.

Résumé. Arrière plan: La densité minérale osseuse (DMO), le contenu minéral de l’os (CMO) et la taille de l’os, ont fait l’objet de nombreuses études au niveau individuel, en relation avec le risque de fracture ostéoporotique, mais la corrélation et les responsabilités relatives des facteurs génétiques et environnementaux entre les paires de ces trois phénotypes sont encore peu connues.

Objectif: L’étude porte sur la corrélation génétique (ρ_G), environnementale (ρ_E) et phénotypique (ρ_p) entre DMO, CMO et taille de l’os.

Sujets et méthodes: Des analyses bivariées de décomposition de la variance ont été effectuées sur 904 sujets de 287 familles nucléaires chinoises.

Résultats: Des ρ_G, ρ_E, ρ_p ont été détectées entre DMO, CMO et taille de l’os, à l’exception de ρ_E entre DMO et taille de l’os à la hanche (ρ_E?=?0,121, p?=?0,361). Des facteurs génétiques communs expliquent respectivement 86,1% et 60% des variations génétiques de DMO et CMO du rachis et de la hanche. Les corrélations génétiques et environnementales entre DMO et taille de l’os sont cependant limitées. Les ρ_G, ρ_E, au rachis sont respectivement 0,392 et 0,381 et sont 0,121 et -0,205 à la hanche. Seulement 14,5% et 4,2% des variations entre DMO et taille de l’os au rachis et à la hanche peuvent être dus à des facteurs génétiques communs.

Conclusion: Les résultats suggèrent que par suite des corrélations limitées qui lient la DMO et la taille de l’os, cette dernière peut être utilisée comme phénotype de substitution, indépendamment de la DMO, pour l’élucidation de la pathogenèse de l’ostéoporose.

Zusammenfassung. Hintergrund: Knochendichte (bone mineral density, BMD), Knochenkalkgehalt (bone mineral content, BMC), und Knochengröße (bone size) sind als bedeutsame individuelle Risikofaktoren für osteoporotische Frakturen umfangreich untersucht worden, aber es ist wenig über die Korrelation und das Ausmaß der beteiligten genetischen und Umwelt-Faktoren zwischen jeweils zwei der drei phänotypischen Parameter bekannt.

Ziel: Die Studie untersucht die genetische Korrelation (ρ_G), die umweltbedingte Korrelation (ρ_E) und die phänotypische Korrelation (ρ_P) zwischen BMD, BMC and Knochengröße.

Probanden und Methoden: Bivariate Varianz-Dekompositionsanalysen wurden bei 904 Probanden aus 287 Chinesischen Kernfamilien untersucht.

Ergebnisse: Signifikante ρ_E, ρ_G and ρ_P wurden zwischen BMD, BMC und Knochengröße entdeckt, mit Ausnahme von ρ_E zwischen BMD und Knochengröße im Hüftbereich (ρ_E?=?0,121, p?=?0,361). Gemeinsame genetische Faktoren erklärten jeweils 86,1% und 60% der genetischen Variation von BMD und BMC an Wirbelsäule und Hüfte. Allerdings waren die genetischen und umweltbedingten Korrelationen zwischen BMD und Knochengröße gering. ρ_E und ρ_G an der Wirbelsäule waren 0,392 und 0,381, und an der Hüfte jeweils 0,121 und –0,205. Nur 14,5% und 4,2% der Variation zwischen BMD und Knochengröße im Bereich von Wirbelsäule und Hüfte könnten durch gemeinsame genetische Faktoren bedingt sein.

Zusammenfassung: Die dargestellten Ergebnisse legten nahe, dass Knochengröße möglicherweise ein weiterer Ersatzparameter ist, der, wegen der begrenzten Korrelation zwischen BMD und Knochengröße, unabhängig vom BMD genutzt werden könnte, um die Pathogenese der Osteoporose aufzuklären.

Resumen. Antecedentes: La densidad mineral ósea (DMO), el contenido mineral del hueso (CMH) y el tamaño del hueso han sido ampliamente estudiados de manera individual como importantes factores de riesgo de fractura osteoporótica, pero se conoce poco acerca de la correlación y del grado en que se comparten los factores genéticos y ambientales entre estos tres fenotipos, considerados dos a dos.

Objetivo: El estudio investigó la correlación genética (ρ_G), la correlación ambiental (ρ_E) y la correlación fenotípica (ρ_P), entre la DMO, el CMH y el tamaño del hueso.

Sujetos y métodos: Se realizaron análisis bivariados de descomposición de la varianza en 904 sujetos de 287 familias nucleares chinas.

Resultados: Se detectaron significativas ρ_E, ρ_G y ρ_P entre la DMO, el CMH y el tamaño óseo, excepto para la ρ_E entre la DMO y el tamaño óseo en la cadera (ρ_E=0,121, p=0,361). Los factores genéticos comunes compartidos explicaban el 86,1% y el 60% de la DMO y las variaciones genéticas del CMH en la espina dorsal y la cadera, respectivamente. Sin embargo, las correlaciones genéticas y ambientales entre la DMO y el tamaño del hueso fueron limitadas. Las ρ_E y ρ_G en la espina dorsal fueron de 0,392 y 0,381, y en la cadera de 0,121 y -0,205, respectivamente. Sólo el 14,5% y el 4,2% de las variaciones entre la DMO y el tamaño del hueso en la espina dorsal y la cadera podían ser debidas a los factores genéticos compartidos.

Conclusión: Los resultados sugieren que el tamaño del hueso puede utilizarse como otro fenotipo sustitutivo, con independencia de la DMO, en el eventual esclarecimiento de la patogénesis de la osteoporosis, debido a las limitadas correlaciones entre la DMO y el tamaño del hueso.