Water- and fat-suppressed proton projection MRI (WASPI) of rat femur bone.

Investigators often study rats by microCT to investigate the pathogenesis and treatment of skeletal disorders in humans. However, microCT measurements provide information only on bone mineral content and not the solid matrix. CT scans are often carried out on cancellous bone, which contains a significant volume of marrow cells, stroma, water, and fat, and thus the apparent bone mineral density (BMD) does not reflect the mineral density within the matrix, where the mineral crystals are localized. Water- and fat-suppressed solid-state proton projection imaging (WASPI) was utilized in this study to image the solid matrix content (collagen, tightly bound water, and other immobile molecules) of rat femur specimens, and meet the challenges of small sample size and demanding submillimeter resolution. A method is introduced to recover the central region of k-space, which is always lost in the receiver dead time when free induction decays (FIDs) are acquired. With this approach, points near the k-space origin are sampled under a small number of radial projections at reduced gradient strength. The typical scan time for the current WASPI experiments was 2 hr. Proton solid-matrix images of rat femurs with 0.4-mm resolution and 12-mm field of view (FOV) were obtained. This method provides a noninvasive means of studying bone matrix in small animals.     

Plasma pharmacokinetics of high-dose oral busulfan in children and adults undergoing bone marrow transplantation

Abstract: We have analyzed the plasma pharmacokinetics of busulfan in 272 patients receiving high-dose oral busulfan and intravenous cyclophosphamide in conjunction with allogeneic or autologous bone marrow transplantation. The patients ranged in age from 2 months to 59 yr (mean 10, median 12 yr) and had the following diagnoses: thalassemia or sickle cell anemia (n = 74); leukemia or myelodysplasia (n = 112); inborn errors of metabolism (n = 41) or immunodeficiency (n = 45). Plasma specimens were collected following the first dose for each patient which ranged from 1 to 4 mg/kg (mean ± SD, 1.21 ± 0.41, median 1.15). Busulfan was quantitated using ultraviolet absorbance detection after derivatization and HPLC separation. Pharmacokinetic parameters were derived by modeling the raw data to fit first-order single compartment kinetics. The kinetic parameters showed wide interpatient variability independent of age and diagnosis. There was a statistically significant correlation of age with the following parameters: area under the curve (AUC); maximal concentration; minimum concentration; clearance; volume of distribution and absorption half-time. The coefficients of determination (i.e. correlation coefficient squared) were low ranging from 0.04 to 0.12 implying only a small part (i.e. 4–12%) of the variance was explained by age. Although busulfan pharmacokinetics are age-related most of the variability is not explained by age or diagnosis.     

骨巨细胞瘤继发动脉瘤样骨囊肿的影像诊断

目的提高骨巨细胞瘤（GCT）继发动脉瘤样骨囊肿（ABC）的认识和影像诊断水平。方法搜集经手术病理证实的12例GCT继发ABC的X线、CT、MRI和病理学资料，分析和总结其影像征象。结果12例中6例病变发生于长管状骨，6例发生于盆骨。12例病变X线均表现为囊状膨胀性溶骨性骨破坏，10例呈偏心性破坏，2例为中心性破坏；4例病灶内出现骨性分隔，6例骨皮质中断，4例出现软组织肿块，有明显硬化边者2例。10例行MR平扫和增强检查，均呈多囊的囊实性膨胀性肿块，8例为边缘性实性结节，2例为实性基础上的广泛囊变，全部患者均可见多个液一液平面，7例出现软组织肿块；1例肿块内可见局灶性含铁血黄素沉着。8例行螺旋cT平扫、增强、CT血管成像（CTA）和三维（3D）多平面重组（MPR），病变显示为囊实性肿块，骨皮质破裂并形成软组织肿块5例，6例肿块内出现液．液平面，全部肿块实质性部分和囊壁明显强化，囊性部分不强化，3例肿块内可见增粗迂曲的供血动脉，未发现动静脉畸形。12例手术所见和术后病理显示肿块均由多发含血的囊腔和实性部分组成，病理诊断结果均为GCT伴发ABC，其中Ⅱ级GCTl0例，Ⅲ级2例。结论GCT伴发ABC并不少见，充分理解其病理组织学基础，并选择恰当的影像检查方法（X线＋MRI或X线＋CT）对其正确诊断非常重要。     

Distal radial fractures Injectable calcium phosphate bone cement versus conventional treatment

AMEDLINEsearchwasconductedtoidentifystudiespublishedfromJanuary1999toMarch2004thatcom-paredinjectablecalciumphosphatebone(NorianSRS)cementwithconventionaltreatmentindistalradialfrac-tures.Fromalistof13articlesidentifiedfromthesearchstrategy,fourarticleswe…     

持续成骨力值对犬骨盆弓状线部骨折愈合的影响

[目的]探讨持续顺应生理力线的压应力对犬骨盆弓状线部骨折愈合的影响.[方法]选用10只成年杂种家犬,双侧髋臼臼顶上方1.5 cm处横形截骨,分别采用ATMFS（骨盆髋臼三维记忆内固定系统）前柱固定器和5孔重建钢板内固定,于术后2、4、6、8、12周处死动物取材,行HE染色、Masson三色法染色组织学检查,图像分析新骨形成积分光密度值,研究不同应力作用模式下的骨盆骨折愈合情况.[结果]ATMFS侧软骨组织形成,骨皮质、骨小梁及胶原纤维成熟时间明显早于钢板侧,术后6、8、12周,两侧骨折端新骨生成面积之间存在显著性差异（P＜0.05）.[结论]ATMFS固定后于骨折端产生的持续顺应生理力线的压应力能够刺激骨折端成骨细胞的形成及骨胶原的合成与分泌,促进骨折早期愈合.     

A Tissue-Engineered Artificial Bile Duct Grown to Resemble The Native Bile Duct

The aim of this study was to fabricate an artificial bile duct for the development of a new treatment for biliary diseases. Eighteen hybrid pigs were implanted with a bile duct organoid unit (BDOU) made of a bioabsorbable polymer. Twelve of the transplanted BDOUs had been seeded with autologous bone marrow cells (BMCs) in advance. Six animals, the controls, were grafted with the scaffold alone with no BMCs seeded. The common bile duct was cut, the hepatic cut end of the native common bile duct was anastomosed to the BDOU and the other end was anastomosed to the duodenum. The controls underwent a similar operation. The neo-bile duct was removed at pre-determined time points and investigated histologically. All 18 recipient pigs survived until their sacrifice at 6 weeks, 10 weeks or 6 months. Histological examination revealed incomplete epithelialization of the neo-bile duct at 6 weeks and 10 weeks after transplantation. At 6 months, the organoid exhibited a morphology almost identical to that of the native common bile duct. No differences were found between the controls and BMC-seeded pigs. These results show that the artificial bile duct thus fabricated can serve as a substitute for the native bile duct.     

Effects of gastric bypass procedures on bone mineral density,calcium, parathyroid hormone,and vitamin d

Weight loss after gastric bypass procedures has been well studied, but the long-term metabolic sequelae are not known. Data on bone mineral density (BMD), calcium, parathyroid hormone, and vitamin D were collected preoperatively and at yearly intervals after gastric bypass procedures. A total of 230 patients underwent preoperative BMD scans. Fifteen patients were osteopenic preoperatively, and three patients subsequently developed osteopenia postoperatively within the first year. No patient had or developed osteoporosis. At 1 year, total forearm BMD decreased by 0.55% (n = 91; P = .03) and radius BMD had increased overall by 1.85% (n = 23; P = .008); both total hip and lumbar spine BMD decreased by 9.27% (n = 22; P < .001) and 4.53% (n = 31; P < .001), respectively. By the second postoperative year, BMD in the total forearm had decreased an additional 3.62% (n = 14; P<.001), whereas radius BMD remained unchanged. Although total hip and lumbar spine BMD significantly decreased at 1 year, by year 2 both total hip and lumbar spine BMD only slightly decreased and were not significantly different from before the operation. Serum calcium decreased from 9.8 mg/dL to 9.2 during the first year (not significant [NS]) and then to 8.8 (NS) by the second year. Parathyroid hormone increased from 59.7 pg/mL (nl 10-65 pg/mL) preoperatively to 63.1 during year 1 (NS) and continued to increase to 64.7 by year 2 (NS). No difference was noted among levels of 25-hydroxy vitamin D preoperatively (25.2 ng/mL; nl 10-65 ng/mL), at 1 year (34.4), and at 2 years (35.4). Our data indicate that bone loss is highest in the first year after gastric bypass with stabilization, and that, in some cases, there is an increase in bone density after the first year. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18, 2005 (oral presentation).     

The Role of Donor Bone Marrow Infusions in Withdrawal of Immunosuppression in Adult Liver Allotransplantation

We investigated the role of donor bone marrow cell (DBMC) infusions in immunosuppression withdrawal in adult liver transplantation. Patients enrolled were at least 3 years post-transplantation, with stable graft function. Forty-five (study group: G1) received DBMC, and 59 (control group: G2) did not. Immunosuppression was reduced by one third upon enrollment, by another third the second year of the study and was completely withdrawn the third year. Patient and graft survival were similar between the two groups. Although rejection episodes were significantly less in G1 the first 2 years of the study (35% vs. 57%, p = 0.016), there was no significant difference overall (74% vs. 81%, p = 0.14). Until February 2004, 20 patients, 10 in each group, were immunosuppression free for 1-3 years. Approximately 20% of long-term survivors of liver transplantation can successfully discontinue their immunosuppression. DBMC infusions, do not increase this likelihood.     

Fas、Bcl-2在γ射线体外诱发的白血病小鼠骨髓细胞中的表达

目的 :观察 Fas、Bcl- 2在 γ射线体外诱发的急性淋巴细胞白血病小鼠骨髓细胞中表达情况 ,以探讨辐射致癌的机制。方法 :采用 4次 1.75 Gyγ射线全身照射 BAL B/ c小鼠诱发白血病模型 ,通过流式细胞仪对照射后白血病组、未癌变组及对照组小鼠骨髓细胞中 Fas、Bcl- 2的表达进行检测 ;应用抗 Fas抗体诱导细胞凋亡 ,进一步观察 Fas、Bcl- 2的表达对骨髓细胞凋亡的影响。 结果 :白血病小鼠骨髓细胞 Fas表达较未癌变组及对照组明显下降 (P<0 .0 1) ,而 Bcl- 2的表达明显增强 (P<0 .0 1) ;白血病小鼠骨髓细胞明显耐受抗 Fas抗体诱导的细胞凋亡。 结论 :Fas低表达、Bcl- 2高表达导致了细胞凋亡受到抑制 ,这可能是辐射引起小鼠急性淋巴细胞白血病的机制之一。     

以冻干骨为平台重建组织工程化关节软骨的研究

目的:探索在兔冻干异体骨关节平台上利用组织工程的方法再造人工关节软骨的可行性。方法:实验分成四组,运用组织工程方法将不同构成的同种异体兔软骨细胞-支架材料复合物种植于兔冻干异体骨关节平台上,植入实验兔体内,3月后取材观察体内成软骨情况。结果:仅种植兔软骨细胞的冻干骨关节支架上未见新生软骨形成。粘合有种植兔软骨细胞的PLGA膜片的冻干骨支架关节腔内见新生类软骨样物出现。自体软骨层孔洞缺损模型使用软骨细胞-PLGA膜片复合物可修复软骨缺损。结论:软骨细胞-PLGA膜片复合物实验动物关节内可形成软骨样物;但在冻干骨关节平台上尚不能形成有功能意义的关节软骨层。