Rupture of the posterior tibial tendon: CT and surgical findings

Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture.     

Mutations in raised Drosophila melanogaster affect experience-dependent aspects of sexual behavior in both sexes

Many aspects of the reproductive behavior of Drosophila melanogaster are modified dramatically by experience and age. Males' courtship of immature males and fertilized females decreases over time. Females' receptivity to copulation, and the behaviors that females perform and elicit, are affected by their age and sexual experience. We show that mutations in a raised stock affect all of these age- and experience-dependent aspects of male and female sexual behavior. Experience has no effect on raised males' courtship of immature males and has opposite effects on raised and wild-type males' courtship of fertilized females. In comparison to controls, raised females become sexually mature at an earlier age, and sexually mature raised virgin females copulate more quickly. Following mating, raised females elicit more courtship and remate faster and more frequently than control females.     

二氢青蒿素的变旋作用与差向异构体转化研究

二氢青蒿素在极性溶媒中,其旋光度随时间而变化,可达一恒定值。高效液相色谱测定表明,在溶液中,该物质有一自β差向异构体向α型转化的动力学过程,此过程与旋光度的变化相对应,其转化速率常数随溶剂、温度而异,酸具催化作用。这一现象的本质是半缩醛的变旋作用。     

拉米夫定抗乙型肝炎病毒治疗中耐药突变的后续治疗

拉米夫定(lamivudine)抗乙型肝炎病毒治疗中耐药突变发生率高,文献报道在拉米夫定治疗1,2,3,4,5a时分别为14%,38%,49%,66%,69%.耐药突变可导致血清HBVDNA水平阳转或明显上升,肝功能严重受损,甚至病情恶化死亡.关于拉米夫定抗乙型肝炎病毒治疗中耐药突变的后续治疗目前国内外尚无统一用药方案,单药治疗(如:继续使用拉米夫定、阿德福韦、恩替卡韦)在临床使用中已经取得了一定疗效,联合抗病毒治疗和中医药治疗是今后研究的方向.     

Transcatheter biventricular conversion in an adult patient with a 1.5 ventricle Glenn palliation and superior vena cava syndrome

Covered stents have a continually expanding spectrum of applications for patients with congenital heart disease. Here we report use of covered stents to successfully perform a first‐in‐human percutaneous biventricular conversion of a 1.5 ventricle Glenn palliation in an adult born with pulmonary atresia. This case demonstrates that in patients considered borderline for biventricular repair, surgery can potentially be modified to promote growth of underdeveloped structures and setup for transcatheter biventricular conversion.     

Heterotopic Bone Formation About the Hip Undergoes Endochondral Ossification: A Rabbit Model

Background

Heterotopic ossification (HO) occurs most commonly after trauma and surgery about the hip and may compromise subsequent function. Currently available animal models describing the cellular progression of HO are based on exogenous osteogenic induction agents and may not reflect the processes following trauma.

Questions/purposes

We therefore sought to characterize the histologic progression of heterotopic bone formation in an animal model that recapitulates the human condition without the addition of exogenous osteogenic material.

Methods

We used a rabbit model that included intramedullary instrumentation of the upper femur and ischemic crush injury of the gluteal muscle. Bilateral surgical induction procedures were performed on 30 animals with the intention of inciting the process of HO; no supplemental osteogenic stimulants were used. Three animals were sacrificed at each of 10 predetermined times between 1 day and 26 weeks postoperatively and the progression of tissue maturation was graded histologically using a five-item scale.

Results

Heterotopic bone reliably formed de novo and consistently followed a pathway of endochondral ossification. Chondroid elements were found in juxtaposition with immature woven bone in all sections that contained mature osseous elements.

Conclusions

These results establish that HO occurs in an animal model mimicking the human condition following surgical trauma about the hip; it is predictable in its histologic progression and follows a pathway of endochondral bone formation.

Clinical Relevance

By showing a consistent pathway of endochondral ossification leading to ectopic bone formation, this study provides a basis for understanding the mechanisms by which HO might be mitigated by interventions.     

Oral bone loss induced by mineral deficiency in a rat model: Effect of a synthetic bone mineral (SBM) preparation

Osteoporosis affects the craniofacial and oral structures and has been associated with periodontal bone loss, tooth loss and reduced jaw bone mass.ObjectiveThis study aimed to test the therapeutic efficacy of synthetic bone mineral (SBM) in minimizing alveolar bone loss induced by mineral deficiency in a rat model. SBM consists of a calcium carbonate apatite (similar to bone apatite) matrix incorporating magnesium, zinc, and fluoride ions.DesignThirty female Sprague Dawley rats (2 months old) were randomly distributed into 3 groups (10 rats per group): GA (control), on basic diet; GB, on mineral deficient (MD) diet; and GC, on MD + SBM. The rats were sacrificed after 3 months, the jawbones were isolated and the soft tissues removed. Bone density was determined using X-ray radiography (Faxitron); mandibular cortical width, panoramic mandibular index, and alveolar resorption degree (M/M ratio) using BioquantOsteo; and bone micro-architecture micro-computed tomography and scanning electron microscopy.ResultsCompared to control (GA), the rats on MD diet (GB) experienced significant mandibular bone loss while the rats on MD + SBM diet (GC) experienced significantly less bone loss compared to the GB group.ConclusionSBM, administered orally, may have the potential as an osteoporosis therapeutic agent in minimizing or preventing alveolar bone loss induced by mineral deficiency.