Ulnar distribution of reflex sympathetic dystrophy due to compression of the brachial plexus by a primary venous malformation

An atypical variant of reflex sympathetic dystrophy (RSD) is presented in a 45 year old female with a vascular malformation of the right arm and chest wall. The mechanism was thought to be compression of the brachial plexus by the malformation. The unique scintigraphic features of this presentation of RSD in the ulnar arterial distribution are illustrated.     

肢体不同延长速度对局部血流量的影响

本文报告20只兔胫骨以不同速度延长时用末梢微循环测定系统动态连续监测局部血流量变化的结果,发现一次延长>1 mm时,局部肌肉血流量开始急骤下降,恢复延长前血流量所需的时间>8 h。作者认为肢体的血管、肌肉等组织对1 mm/次/d延长速度有相当大的生物适应性。延长速度>1 mm/次/d易造成局部血流量大幅度减少。延长肢肌肉萎缩、肌力减弱可能与血流量减少有关。     

Quantitation of T2′ anisotropic effects on magnetic resonance bone mineral density measurement

In this paper, the authors quantitate the anisotropy of susceptibility effects in an uniaxial trabecular bone model and show its relevance to clinical MR bone mineral density measurements. A physical model is described that quantitates the anisotropic MR behavior of uniaxial trabecular bone. To test the model, a phantom of parallel polyethylene filaments was scanned every 15° between 0° and 90° with respect to the system's main magnetic field (B₀). The distal radial metaphysis of a healthy female volunteer was scanned in orthogonal projections. The signal from each phantom image and each radial image was separated in a pixel-wise fashion into R₂ and R₂′ maps. As predicted, R₂′ relaxation showed anisotropic behavior and changed according to sin² (?), confirming that columnar structures parallel with B₀ will cause no MR susceptibility effects. Scans of the distal radius showed that R₂′ relaxation was twice as great with the forearm perpendicular to B₀ as when it was parallel to it, demonstrating different contributions from struts and columns. For both phantom and radial bone scans, R₂ relaxation was isotropic and did not change with object orientation.     

跟骨骨折的手术治疗

目的 探讨跟骨骨折手术治疗方法。方法 采用外侧切口，通过跟骨外侧骨皮质开门．将骨折复位后植骨．重建钢板螺钉内固定术．治疗24例（26足)。结果 术后均获5～32个月随访，按门振武等评分际准．优17例，良5例，差2例．结论 严重跟骨骨折手术治疗效果较满意。     

Benign osteoblastoma of the occipital bone: Case report and literature review

We present a case of benign osteoblastoma of the occipital bone. Benign osteoblastoma is an uncommon primary bone tumor, which usually involves the vertebrae and the long bones. This tumor rarely develops in the calvaria, showing a preference for the temporal and frontal bones when it does. To the best of our knowledge, this case is only the eighth reported case of benign osteoblastoma confined to the occipital bone. A 20‐year‐old male presented with a mild tender mass lesion of the occipital area, just below the lambda. Plain X‐ray films and CT scans demonstrated an osteolytic mass surrounded by the sclerotic rim within the diploic space. MRI proved to be effective for the evaluation of the intracranial and intraosseous extensions of the tumor. However, it was very difficult to formulate a differential diagnosis against other osteoblastic tumors, or osteoid osteoma, in view of its radiological appearance. The final diagnosis was obtained by careful consideration of the histopathological characteristics of the tumor combined with its clinical and radiological features. Although generally regarded as benign, a complete resection is preferred over conventional curettage as this can guard against possible recurrence and malignant transformation.     

急性苯中毒对小鼠末梢血象和骨髓细胞构成的影响

取３２只２～３个月的ＢＡＬＢ／Ｃ小白鼠，随机分为４组，每组８只，第１组为对照组，其余３个组为实验组，实验组小白鼠左腿皮下注射苯０．３ｍｌ（１５ｍｌ／ｋｇ体重）．注射后分别于２４ｈ，４８ｈ，７２ｈ脱颈处死。观察中毒前、后末梢血象、骨髓细胞、骨髓细胞构成的变化。结果表明，苯中毒时骨髓变化先于末梢血象的变化，骨髓的病变为造血细胞变性、坏死，大量毛细血管扩张、充血，骨髓细胞构成降低，而且骨髓细胞构成中细胞成分降低早于外周血粒细胞减少。     

Rhizomelic Bone Dysplasia with Club-like Femora (Case report and confirmation of a syndrome)

A newborn with rhizomelic bone dysplasia with club-like femora is reported. This is the fourth case Of this easily recognizable, recently reported, congenital bone disease. Maroteaux et al recently reported two patients with rhizomelic bone dysplasia and club-like femora as a distinctive new bone dysplasia. Their observation was confirmed by Gugliantini et al (2) who reported another case. This paper reports a fourth patient with this easily recognisable disorder.     

Inflammatory mediators and the destruction of bone

Bone is remodelled by the coordinated actions of osteoclasts and osteoblasts. Cellular remodelling occurs in discrete packets of bone, and is regulated by local cytokines produced in the environment of the remodelling cells. These cytokines are secreted by immune cells and by bone cells. In addition, some growth regulatory factors are incorporated into the noncollagenous bone matrix and are released in an active form when bone is stimulated to resorb. Complex interactions between these cytokines and their target cells are responsible for the normal delicate balance between bone resorption and bone formation, and disorders of bone loss are due to imbalances between the rates of resorption and formation.     

A Bayesian approach to subvoxel tissue classification in NMR microscopic images of trabecular bone

NMR microscopy is currently being used as an investigational tool for the evaluation of micromorphometric parameters of trabecular bone as a possible means to assess its strength. Since, typically, the image voxel size is not significantly smaller than individual trabecular elements, partial volume blurring can be a major complication for accurate tissue classification. In this paper, a Bayesian segmentation technique is reported that achieves improved subvoxel tissue classification. Each voxel is subdivided either into eight subvoxels twice the original resolution, or up to four subvoxels along the transaxial direction and the subvoxels optimally classified as either bone or marrow. Based on a statistical model for partial volume blurring, the likelihood for the number of marrow subvoxels in each voxel can be computed on the basis of its measured signal. To resolve the ambiguity of the location of the marrow subvoxels, a Gibbs distribution is introduced to model the interaction between the subvoxels. Neighboring subvoxel pairs with the same tissue label are encouraged, and pairs with distinct labels are penalized. The segmentation is achieved by maximizing the a posteriori probability of the label image using the block ICM (iterative conditional mode) algorithm. The potential of the proposed technique is demonstrated in real and synthetic NMR microscopic images.     

A 4-year controlled clinical study into the use of a ceramic hydroxylapatite implant material for the treatment of periodontal bone defects

10 patients with chronic adult periodontitis who had greater than 1 tooth with infra-bony pockets were treated at the test defects by periodontal flap procedures with implantation of hydroxylapatite particles; the control defects were treated by the same surgical procedures but without the implant. A total of 58 test defects and 59 control defects were treated. Each defect had measurements carried out at given sites on the involved tooth surfaces, the sites being considered for subsequent tabulation purposes under the category of shallow (less than 3 mm) moderate (3-6 mm) and deep (greater than 6 mm) initial pocket depths. There were 146 and 152 shallow sites, 216 and 241 moderate sites and 140 and 133 deep sites, at test and control sites, respectively. Measurements of recession, probing pocket depths and probing attachment levels were made at 6 months and 1, 2, 3 and 4 years. At all sites over the period of the study, for the moderate and deep initial pockets there was a significant reduction in probing depths and an increase in the probing attachment levels. At the 4th year of assessment for the initially deep pockets, the reduction in probing depths was significantly greater for the sites treated with the implant material. In view of the difficult clinical problem posed by the treatment of teeth with deeper periodontal bone defects, further research using either this type of implant material or similar material should be considered.