Intrathecal methotrexate overdose

We report two cases of intrathecal methotrexate overdose. A 3-y-old girl with acute lymphoblastic leukaemia and a 4-y-old boy with Burkitt's lymphoma were to receive an intrathecal injection of methotrexate after completion of intravenous methotrexate infusion. Instead of 12.5 mg, they both received a dose of 125 mg. Both children developed generalized convulsion 3 h after the overdose, but afterwards recovered completely. Intravenous folinic acid and dexamethasone rescue were employed, but no attempt was made to exchange the cerebrospinal fluid. In addition to the staffs failure to check the drug label carefully, the marked resemblance of the two dose preparations of methotrexate (50 mg/5 ml and 500 mg/5 ml) may have been contributory.     

Some Theoretical Underpinnings of Knowledge Translation

A careful analysis of the definition of knowledge translation highlights the importance of the judicious translation of research into practice and policy. There is, however, a considerable gap between research and practice. Closing the research-to-practice gap involves changing clinical practice, a complex and challenging endeavor. There is increasing recognition that efforts to change practice should be guided by conceptual models or frameworks to better understand the process of change. The authors conducted a focused literature search, developed inclusion criteria to identify planned action theories, and then extracted data from each theory to determine the origins, examine the meaning, judge the logical consistency, and define the degree of generalizability, parsimony, and testability. An analysis was conducted of the concepts found in each theory, and a set of action categories was developed that form the phases of planned action. Thirty-one planned action theories were identified that formed the basis of the analyses. An Access database was created, as well as a KT Theories User's Guide that synthesizes all the planned change models and theories, identifies common elements of each, and provides information on their use. There are many planned change models and frameworks with many common elements and action categories. Whenever any planned change model is used, change agents should consider documenting their experiences with the model so as to advance understanding of how useful the model is and to provide information to others who are attempting a similar project.     

Evidence for growth hormone (GH) autoregulation in pituitary somatotrophs in GH antagonist-transgenic mice and GH receptor-deficient mice

Growth hormone (GH) modulates the hypothalamic release of somatostatin and GH-releasing hormone; however, there has been no evidence of GH autoregulation on the pituitary somatotroph. To determine the effects of GH on its own regulation, we examined the pituitaries of giant transgenic mice expressing a GH agonist (E117L), dwarf transgenic mice expressing a GH antagonist (G119K), and dwarf mice devoid of the GH receptor/binding protein (GHR/BP). In the E117L transgenic mice, the number and distribution of pituitary GH-immunoreactive cells were unchanged from nontransgenic littermate controls; an ultrastructural examination revealed typical, densely granulated somatotrophs. In contrast, the pituitaries of the G119K mice contained both moderately granulated somatotrophs and a sparsely granulated (SG) population with well-developed synthetic organelles and a distinct juxtanuclear globular GH-staining pattern. GHR/BP-deficient mice exhibited a marked reduction in the intensity of cytoplasmic GH immunoreactivity; however, prominent GH staining in the juxtanuclear Golgi was seen. GH-immunoreactive cells were increased in number, and the reticulin network pattern was distorted; stains for proliferating cell nuclear antigen confirmed mild hyperplasia. Electron microscopy showed that the somatotrophs were hyperactive SG cells with prominent endoplasmic reticulum membranes, large Golgi complexes, and numerous mitochondria. These findings are consistent with synthetic and secretory hyperactivity in pituitary somatotrophs due to the reduced GH feedback regulation. The changes are most striking in animals that are devoid of GHR/BP and less marked in animals expressing a GH antagonist; both models had reduced insulin-like growth factor-I levels, but the more dramatic change in the GHR/BP animals can be explained by abrogated GH signaling. This represents the first evidence of direct GH feedback inhibition on pituitary somatotrophs, which may have implications for the use of GH analogs in different clinical settings.     

Percutaneous transluminal angioplasty of infrapopliteal vessels: preliminary results and technical considerations

Infrapopliteal balloon angioplasty was performed in 11 patients facing reconstructive surgery for limb salvage. Twelve separate sessions of angioplasty were performed, during which 15 of 16 diseased tibial runoff vessels were successfully dilated. Three complications occurred during percutaneous transluminal angioplasty (PTA). One was related to the concomitant use of a thrombolytic agent to open a femoropopliteal bypass graft and not related to the angioplasty itself. No limbs were lost as a result of complications. The procedure was a technical success in nine of 12 cases (75%) and an initial clinical success in eight of the nine that were technically successful (89%). Follow-up ranged from 1 to 22 months. Six of the nine cases (67%) remained clinically successful during this period. Preliminary results suggest that infrapopliteal PTA is a safe and effective alternative to surgical reconstruction in selected patients.     

比较肾动态显像与静脉肾盂造影在泌尿系统疾病的临床价值

1 对象和方法 1.1 对象 本院住院肾脏疾病患者71(男43,女28)例,平均年龄42.8岁.其中泌尿系结石42例,输尿管狭窄10例,肾萎缩8例,肾癌、肾结核、慢性肾功能衰竭各3例,多囊肾、前列腺增生各1例,共80个患肾,其中17例行手术治疗.