Osteonecrosis of the jaw and bisphosphonate treatment for osteoporosis

A potential side effect associated with bisphosphonates, a class of drugs used in the treatment of osteoporosis, Paget's disease and metastatic bone disease, is osteonecrosis of the jaw (ONJ). The incidence of ONJ in the general population is unknown; this rare condition also may occur in patients not receiving bisphosphonates. Case reports have discussed ONJ development in patients with multiple myeloma or metastatic breast cancer receiving bisphosphonates as palliation for bone metastases. These patients are also receiving chemotherapeutic agents that might impair the immune system and affect angiogenesis. The incidence or prevalence of ONJ in patients taking bisphosphonates for osteoporosis seems to be very rare. No causative relationship has been unequivocally demonstrated between ONJ and bisphosphonate therapy. A majority of ONJ occurs after tooth extraction. Furthermore, the underlying risk of developing ONJ may be increased in osteoporotic patients by comorbid diseases. Treatment for ONJ is generally conservative.     

Duodenal hematoma: the ring sign in MR imaging

Proper management of duodenal hematoma requires that an accurate diagnosis be made using noninvasive radiological methods. Conventional imaging may be nonspecific if there is no history of trauma or coagulopathy. Two cases of duodenal hematoma that were imaged by magnetic resonance (MR) and computed tomography (CT) are described. In both cases the hematoma had a well-defined concentric ring configuration on MR images, a finding which helped establish the diagnosis. MR imaging may provide tissue-specific characterization of duodenal hematomas.     

(-),(+)黄皮酰胺对鼠脑内 NMDA- 受体的影响

用[³H]MK-801放射配体竟争结合法测定了(-),(+)黄皮酰胺对大鼠前脑,海马,皮层等部位突触膜的NMDA-R的作用,以探讨其促智机制。同时用饱和实验分析po给药10d后,小鼠脑内该受体密度的变化。结果表明:(-),(+)黄皮酰胺对脑内各部位的NMDA受体均无特异亲和力。但(-)黄皮酰胺在体给药10d后能使小鼠脑内NMDA受体密度显著增高,并呈一定的量效关系。提示黄皮酰胺的药理作用有光学选择性;(-)黄皮酰胺增加脑内NMDA受体密度为其促智作用提供了重要理论依据。     

Interleukin-1beta and beta-glucuronidase in gingival crevicular fluid from molars during rapid palatal expansion.

This study examined whether the inflammatory mediators interleukin (IL-1beta) and beta-glucuronidase (betaG) are present in the gingival crevicular fluid (GCF) of children undergoing rapid palatal expansion and whether their levels vary upon activation of the appliance and movement of the maxillary first molars. Nine adolescent patients who needed palatal expansion were studied. Each patient received a periodontal prophylaxis and instruction in proper home care, including rinsing with chlorhexidine. Four weeks later, a modified Hyrax appliance was inserted. The jackscrew was activated twice daily until the appropriate expansion was achieved. GCF samples were collected at 2 pretreatment observation periods and 9 observation periods after placement of the appliance. Samples were collected with filter paper strips and analyzed by means of ELISA and time-dependent fluorometry for IL-1beta and betaG, respectively. The values recorded at the observation period 2 weeks after the periodontal prophylaxis were used as baseline. Paired t tests were used to compare mediator levels at this baseline to the levels obtained at each of the subsequent observations. The results indicate that (1) betaG and IL-1beta are present in GCF of young, healthy individuals, (2) their levels decrease following a strict regimen of plaque control, (3) orthodontic/orthopedic forces evoke changes in the levels of the inflammatory mediators IL-1beta and betaG in the periodontal tissues that can be detected in GCF. The results of this study support the hypothesis that mechanical stimulus causes an inflammatory reaction within the periodontal tissues, which in turn may trigger the biological processes associated with bone remodeling.     

Factors affecting mortality and morbidity in patients with abdominal gunshot wounds

Risk factors that may independently predict mortality and morbidity in patients with abdominal gunshot wounds have not been fully elucidated. We prospectively studied the effects of 12 potential risk factors on mortality and morbidity in 82 patients with abdominal gunshot wounds who required laparotomy. Univariate analysis of these factors revealed that shock on admission, presence of penetrating colon injury and number of intra-abdominal organs injured (NOI)>2 were associated with greater than threefold increased incidence of death (p<0.05). Penetrating abdominal trauma index (PATI) score>15 was associated with twentyfold increased incidence of death (P<0.0001). Multivariate analysis showed that only PATI (P=0.001), number of postoperative complications per patient (N(comp)) (P=0.023) and presence of shock on admission (P=0. 028) were independently significant in predicting mortality. PATI was the only risk factor that independently predicted the development of postoperative infectious complications and N(comp) (P<0.0001). The type of gun used was not a significant risk factor (P>0.05). The 15 (18.3%) non-survivors were significantly older than survivors (P=0.02), had longer operations (P=0.004) and their NOI, PATI and N(comp) were significantly higher (P<0.001). The uniformly prolonged injury to surgery time in all patients contributed to the high incidence of infectious complications (62.2%) and mortality. PATI score was the most important factor found to be independently associated with mortality and morbidity in our subset of patients with prolonged injury to surgery time and high rate of colon injury.     

人参皂甙Rg1对老年大鼠免疫功能的调节作用

已知老年机体免疫功能的降低与淋巴细胞增殖能力的减弱和白细胞介素-2(IL-2)产生减少有密切关系。以老年大鼠免疫功能为主要研究对象,首次发现人参皂甙Rg1无论体内给药还是体外实验均能选择性增强老年大鼠脾淋巴细胞增殖能力和IL-2的产生与释放,采用Northern和Western印迹分析法证明,Rg₁可明显促进IL-2基因和蛋白的表达,表现在IL-2mRNA和IL-2蛋白含量的显著增加。值得注意的是,在同样的条件下,Rg₁对青年大鼠免疫功能的影响并不显著,由此可以认为Rg1一种“免疫调节剂”,而并非单纯的“免疫增强剂”。