阿片受体拮抗剂在TNF－α所致体温升高中的作用

为探索细胞介素ＴＮＦ－α升体温效应与下丘脑前部、视前区（ＰＯＡＨ）中的阿片受体的关系。应用脑神经核团微量注射方法给自由状态下的雄性ＳＤ大鼠ＰＯＡＨ区微量注射ＴＮＦ－α致热源。给药前３０ｍｉｎ分别用通常阿片受体拮抗剂Ｎａｌ（１０～２０μｇ）和特异性阿片受体μ、δ和κ的拮抗剂ＣＴＡＰ（１．０～２．５μｇ）、ＮＴＩ（０．２５～０．５μｇ）和ｎｏｒ－ＢＮＩ（０．１～３μｇ）对ＰＯＡＨ做预处理。结果：单独给ＴＮＦ－α可致剂量相关的体温升高△Ｔ（１℃～１．４℃）；经Ｎａｌ１０μｇ，ＣＴＡＰ１．０μｇ和ＮＴＩ０．５μｇ处理后使ＴＮＦ－α的升体温效应减弱；用Ｎａｌ２０μｇ，ＣＴＡＰ２．５μｇ和ＮＴＩ０．２５μｇ处理后可完全阻断ＴＮＦ－α所致的体温升高；ｎｏｒ－ＢＮＩ（０．１～３μｇ）对ＴＮＦ－α的升体温效应无影响。     

Application of image-guided surface coil P-31 MR spectroscopy to human liver, heart, and kidney

Localized phosphorus-31 magnetic resonance (MR) spectroscopy in humans has previously been accomplished with surface coils by means of depth-resolved surface coil spectroscopy or rotating frame experiments, in which the extent of tissue sampled critically depends on surface coil placement. The authors' goal was to modify the surface coil image-selected in vivo spectroscopy (ISIS) experiment to accomplish three-dimensional volume selection through application of selective pulses in the presence of B0 gradients. Advantages of ISIS include the ability to use proton images to define the volume of interest (VOI) and reduced dependence on exact positioning of the surface coil. However, rapid replication of the surface coil ISIS experiment can cause spectral contamination from signals originating outside the VOI. A modified version of the ISIS experiment was developed to alleviate contamination under conditions of rapid replication. Applications of localized P-31 MR spectroscopy for observation of high-energy phosphorus metabolites are presented in human liver, heart, and transplanted and normal kidney.     

Tetralogy of Fallot: MR findings

Surgical treatment of patients with tetralogy of Fallot requires accurate definition of all anatomic structures, particularly the central pulmonary arteries. Magnetic resonance (MR) images of 22 patients with tetralogy of Fallot were studied to assess their usefulness in providing information regarding the spectrum of anatomic abnormalities in this condition. MR findings were compared with information obtained at catheterization (in 16 patients) and at surgery (in nine patients), both of which were performed within 3 months of MR imaging. Ventricular chamber enlargement and wall hypertrophy were clearly delineated in most of the 17 patients who were examined before definitive surgical repair, and ventricular septal defects were visualized in all 17. Palliative systemic-to-pulmonary shunts were visualized in 11 patients and could be evaluated for patency. Most important, the morphology and size of the right ventricular outflow tract and central pulmonary arteries could be accurately assessed. Pulmonary artery measurements obtained from MR images demonstrated excellent correlation with angiographic measurements. In six patients examined after complete surgical repair, MR images accurately reflected changes in pulmonary artery outflow tract morphology and complications, such as residual pulmonary artery stenosis and thrombosis. The findings suggest that MR imaging can complement or obviate catheterization in the evaluation of tetralogy of Fallot with regard to suitability for definitive surgical repair.     

Risky behavior in teens with cystic fibrosis or sickle cell disease: a multicenter study

OBJECTIVE: To determine the prevalence and age of onset of common risky behaviors such as smoking and sexual activity in teens with cystic fibrosis and those with sickle cell disease and to compare their behaviors with those of adolescents in the general population. DESIGN: Survey. SETTING: All five major pediatric tertiary care centers in North Carolina (study participants with sickle cell disease or cystic fibrosis) and North Carolina public schools (comparison population). PARTICIPANTS: Three hundred twenty-one adolescents with cystic fibrosis or sickle cell disease aged 12 to 19 years (mean age, 15.6 years; 49% female). Demographically matched comparison teens for each group were selected from 2760 in-school adolescents (mean age, 16.0 years; 51% female). MAIN OUTCOMES MEASURES: Prevalence of tobacco and marijuana use, alcohol use, sexual intercourse, sexually transmitted diseases, seat belt use, weapon carrying, and age of onset of these behaviors. RESULTS: Chronically ill teens reported significantly less lifetime and current use of tobacco, marijuana, and alcohol; less sexual intercourse; less weapon carrying, less drunk driving, and more seat belt use than their peers. Nonetheless, 21% of the teens with cystic fibrosis and 30% of those with sickle cell disease had smoked; sexual intercourse was reported by 28% and 51%, respectively. Age of onset of these behaviors was frequently older for the chronically ill teens. CONCLUSION: Teens with cystic fibrosis or sickle cell disease took more potentially damaging health risks than might be expected, although the prevalence was lower than reported by their peers. Future longitudinal studies should examine the relationships between chronic illness, physical and psychosocial maturation, and risky behavior. Screening for psychosocial issues, including risky behaviors, should be incorporated into the routine health care of chronically ill teens.     

Can hydroxyapatite deposition in the eye cause a neutrophil-related inflammatory reaction?

Patients with chronic renal failure on intermittent dialysis sometimes develop an acute diffuse conjunctival and episcleral hyperaemia. In this study the hypothesis was tested whether the precipitation of hydroxyapatite crystals could result in an inflammatory reaction mediated by enzymes liberated from polymorphonuclear leucocytes (PMN). Ingestion of the crystals by PMN's can result in cell death and membranolysis and subsequent release of intracellular enzymes into the surrounding tissues. This suicide sac hypothesis for the inflammatory reactions of the conjunctiva and episclera was rejected after histopathological examination of conjunctival biopsies failed to show complement activation or crystal ingestion by PMN's despite the presence of small subepithelial hydroxyapatite crystals.     

Maternal predictors of early breast milk output

Previous attempts to show a quantitative relationship between maternal hormone levels and early milk output have used small sample sizes and simple correlations. Women of mixed parity and similar socio-economic status and education were recruited to a study using multivariate analysis to look for these associations. Hormone levels (oestradiol, progesterone, prolactin and thyrotropin (TSH)) were determined for 91 mothers at four time points (ante- and postnatally) from finger-prick blood spots by fluoro-immunoassay. Milk output at 1 and 4 weeks was determined from 24-h test weighings. Parity was found to be the most significant factor affecting breast milk volume at 1 wk postpartum (multiparous women delivered 142 ml more milk in 24 h than primiparous women). Total time spent feeding had a strong association with breast milk volume, with increasing time having a negative effect. Multiple regression analysis, controlling for parity and time spent feeding, showed a positive association of milk output at 1 wk with antenatal progesterone and antenatal prolactin levels. At 4 wk, higher postpartum oestradiol levels had a negative association and antenatal progesterone levels a positive association with milk output. This study demonstrates that there are quantitative associations between antenatal maternal hormone levels and breast milk output in the early postnatal period.     

Genetic factors in non‐syndromic congenital heart malformations

Wessels MW, Willems PJ. Genetic factors in non‐syndromic congenital heart malformations. The genetic defect in most patients with non‐syndromic congenital heart malformations (CHM) is unknown, although more than 40 different genes have already been implicated. Only a minority of CHM seems to be due to monogenetic mutations, and the majority occurs sporadically. The multifactorial inheritance hypothesis of common diseases suggesting that the cumulative effect of multiple genetic and environmental risk factors leads to disease, might also apply for CHM. We review here the monogenic disease genes with high‐penetrance mutations, susceptibility genes with reduced‐penetrance mutations, and somatic mutations implicated in non‐syndromic CHM.