Vulnerability and protective factors for posttraumatic stress disorder

A review is given of pre-, peri- and post-traumatic factors that increase or decrease the risk of developing posttraumatic stress disorder (PTSD). With the exception of extremely severe stressors, vulnerability and protective factors explain much of the probability of developing PTSD. The etiology of PTSD is multifactorial, and variables related to the individual, their life situation at the time of exposure, the stressor, and the recovery environment tend to interact.     

Fibril Amyloid Enhancing Factor (FAEF)-Accelerated Amyloidosis in the Hamster is Not Dependent on Serine Esterase Activity and Mononuclear Phagocytosis

Cells of the mononuclear phagocytic system (MPS) were described as playing a decisive role in amyloidogenesis. A relationship between the amyloid enhancing factor (AEF) and MPS cells was suggested and recently AEF activity was attributed to a serine esterase (SE) of leucocytic origin. In the present study, no correlation was found between the SE content and AEF activity in either peritoneal cell lysates or AEF preparations of different origin. Furthermore, pretreatment of fibril AEF (FAEF) with the SE inhibitor phenylmethylsulphonyl fluoride (PMSF) did not affect its activity in the hamster. Blockade of the MPS by dextran sulphate did not inhibit deposition of amyloid after intravenous injection of FAEF but amyloid deposition was inhibited when FAEF was administered intraperitoneally. These results suggest that MPS cells could be involved in transport of AEF, but that phagocytic activity of MPS cells is not essential in AA-amyloid fibrillogenesis. It is concluded that these results are not consistent with the previously suggested nature of the AEF or with the proposed central role of the MPS in amyloidogenesis.     

In vivo evaluation of occlusal wear of two experimental composites versus amalgam

Two experimental inhomogeneous microfilled composites with spherical prepolymerized particles and an interpenetrating network (IPN), which provides a stable bond between prepolymerized spheres and the matrix (B-21 and B-51), and amalgam were used for Class II MOD fillings in mandibular molars. After 3 and 6 months of clinical use, wear of the material was measured with a replica technique and a modified surface roughness test. The failure mode was analysed with SEM photographs also using a replica technique. After 6 months the wear of the composites in the occlusal contact area was more than twice as high as the substance loss of amalgam. It was concluded that the composites were not suitable for fillings bearing occlusal load. However, the failure mode seen in the SEM for B-21 indicated that the IPM leads to a stable incorporation of the spherical prepolymerized particles into the matrix. Due to its good surface characteristics B-21 should be further investigated for its use as an anterior composite. B-51 was especially designed as a posterior composite. Beside the construction elements of B-21 it contained also barium glass spheres to obtain radiopacity. This hybrid construction failed due its wear mode.     

Cystic intracranial lesions: magnetic resonance imaging

Thirty-three patients with cystic intracranial lesions were examined with both magnetic resonance (MR) imaging and CT scanning. The abnormalities imaged included 11 arachnoid cysts, 10 cystic tumors, six postoperative cysts, and three colloid cysts. The intensity patterns of the cyst contents as encoded with routine spin-echo imaging sequences enabled subdivision of the cysts into three categories. Arachnoid and postoperative cysts had an intensity pattern identical to cerebrospinal fluid. More proteinaceous cysts, including inflammatory cysts and nonhemorrhagic tumoral cysts, had an intermediate intensity pattern with characteristically low intensity on the short TR sequence (0.5 sec), but had clearly higher intensity than cerebrospinal fluid on the long TR sequences (2 sec). Finally, three cystic tumors with hemorrhagic fluid and three colloid cysts had a distinctly different pattern of high intensity on all four MR sequences through the same section. MR was superior to CT in characterizing intracranial cystic lesions because of its ability to categorize cysts into these three groups on the basis of the intensity pattern of cyst contents, thereby improving diagnostic specificity and patient management.     

6－甲氧基正丁苯酞的体内代谢转化研究

大鼠用６－甲氧基正丁苯酞（ＭＢＰ）灌胃，收集０～２４ｈ尿液，经酶水解、提取浓缩、衍生化处理后用ＧＣ／ＭＳ分析。在大鼠０～２４ｈ尿液中，６－甲氧基正丁苯酞原药含量很低，主要以代谢物形式存在，依次为Ｃ－６脱甲基产物、Ｃ３－Ｃα环氧化物、γ－羟化物、β－羟化物以及两个次级代谢产物。６－甲氧基正丁苯酞体内代谢结果与其在肝微粒体中代谢结果基本一致。