氯磷酸二钠表面改性羟基磷灰石血清蛋白吸附行为的改变

目的:观察二磷酸盐药物对羟基磷灰石进行表面改性后对材料表面蛋白吸附的影响。方法:实验于2005-06/08在口腔生物医学工程教育部重点实验室完成。①将羟基磷灰石制成10mm×10mm×2mm大小的块状,共48块,随机分为实验组与对照组,每组24块。②实验组羟基磷灰石与氯磷酸二钠复合制成氯磷酸二钠-羟基磷灰石,对照组不复合氯磷酸二钠,用乙醇和蒸馏水超声波清洁,干燥备用。③将两组标本分别置入100g/L小牛血清(蛋白吸附溶液)和0.2mol/LPBS磷酸缓冲液(对照吸附溶液)中浸泡吸附,每种溶液中12块。④通过X射线光电子能谱分析检测和蛋白质电泳对两组材料表面吸附的蛋白进行对比分析。结果:①X射线光电子能谱分析检测提示吸附小牛血清后,实验组和对照组表面氮元素百分含量分别是(9.83±1.33)%和(10.11±1.67)%,差异无显著性意义(P>0.01)。②十二烷基磺酸钠-聚丙烯酰胺凝胶电泳提示两组材料均可以吸附大量白蛋白,实验组表面吸附的白蛋白要少于对照组。③双向电泳提示两组材料表面吸附的蛋白相对分子质量均大于50000;对照组吸附的酸性蛋白量要多一些,实验组表面吸附的碱性蛋白和中性蛋白要多一些;偏酸性的蛋白中,β球蛋白和玻璃粘连蛋白在实验组表面吸附量较对照组表面多。结论:氯磷酸二钠复合羟基磷灰石对材料表面吸附蛋白的种类有一定影响,但对总量没有明显影响。     

THE RENAL HANDLING OF HEMOGLOBIN : I. GLOMERULAR FILTRATION

The glomerular filtration of hemoglobin (α₂β₂) was studied under conditions in which its dissociation into αβ dimers was experimentally altered. Rats receiving hemoglobin treated with the sulfhydryl reagent bis(N-maleimidomethyl) ether (BME) showed a much lower renal excretion and prolonged plasma survival as compared with animals injected with untreated hemoglobin. Plasma disappearance was also prolonged in dogs receiving BME hemoglobin. Gel filtration data indicated that under physiological conditions, BME hemoglobin had impaired subunit dissociation. In addition, BME hemoglobin showed a very high oxygen affinity and a decreased rate of auto-oxidation. Glomerular filtration was enhanced under conditions which favor the dissociation of hemoglobin into dimers. Cat hemoglobin, which forms subunits much more extensively than canine hemoglobin, was excreted more readily by the rat kidney. The renal uptake of ⁵⁹Fe hemoglobin injected intra-arterially into rabbits varied inversely with the concentration of the injected dose.     

国人全膝关节假体置换胫骨近端截骨面至腘血管距离的测量及意义

目的:测量国人全膝关节假体置换术胫骨近端截骨面后缘至腘窝血管之间的距离,以期为临床全膝关节置换术中避免损伤腘窝血管提供参考数据。方法:选择2006-06/12于解放军第二军医大学长征医院体检的50名正常成人(53膝),男29名(31膝),女21名(22膝)。所有观察对象均知情同意,且得到医院伦理道德委员会批准。对所有膝关节进行MRI扫描,在胫骨外侧平台以下10mm水平横断面上辨认腘动静脉,并测量胫骨近端截骨面后缘至腘窝动静脉的距离。结果:53膝全部进入结果分析,无脱落。①男性胫骨近端截骨面后缘至腘动脉、腘静脉平均距离为(6.7±2.5,7.3±2.3)mm,95%可信区间分别为5.8～7.6mm,6.5～8.1mm。②女性胫骨近端截骨面后缘至腘动脉、腘静脉平均距离为(6.6±1.9,7.1±2.7)mm,95%可信区间分别为:5.8～7.4mm,5.9～8.3mm。③不同性别观察对象胫骨近端截骨面后缘至腘血管的距离差异无显著性意义(P>0.05)。结论:腘窝血管紧邻全膝关节假体置换术胫骨近端截骨面后缘,不同性别间无明显差异。全膝关节假体置换术中进行胫骨近端截骨,特别是后方操作时需特别谨慎,以避免损伤腘窝血管。     

A population-based survey of the epidemiology of symptom-defined gastroesophageal reflux disease: the Systematic Investigation of Gastrointestinal Diseases in China

Background

Hepatitis B immune globulins (HBIG) in combination with nucleos(t)ide analogues (NA) are effectively used for the prevention of hepatitis B virus (HBV) recurrence after liver transplantation (LT). However, associated treatment costs for HBIG are exceedingly high.

Methods

Fresh frozen plasma obtained from blood donors with high anti-HBs levels (hyperimmune plasma, HIP) containing at least 4,500 IU anti-HBs was used as alternative treatment for HBV recurrence prophylaxis post-LT.

Results

Twenty-one HBV-related LT recipients received HIP starting at transplantation, followed by long-term combination treatment with NA. Mean follow-up time was 4.5 years (range 0.5-12.6) and each patient received on average 8.2 HIP per year (range 5.8-11.4). Anti-HBs terminal elimination kinetic after HIP administration was 20.6 days (range 13.8-30.9), which is comparable to values reported for commercial HBIG products. All 21 patients remained free of HBV recurrence during follow-up and no transfusion-transmitted infection or other serious complication was observed. Seven patients developed reversible mild transfusion reactions. The cost for one HIP unit was US$140; average yearly HBIG treatment cost was US$1,148 per patient, as compared to US$25,000-100,000 for treatment with commercial HBIG.

Conclusion

The results of this study suggest that the use of HIP may be a useful and economical approach for the prevention of HBV recurrence post-LT if used in combination with NA. Additional prospective controlled studies in larger populations are needed to confirm these results.     

Parental perceptions regarding healthy behaviours for preventing overweight and obesity in young children: a systematic review of qualitative studies

Evidence is increasingly pointing towards the importance of early life strategies to prevent childhood overweight and obesity. This systematic review synthesizes qualitative research concerning parental perceptions regarding behaviours for preventing overweight and obesity in young children. During May and June 2008, a range of electronic databases were searched and together with lateral searching techniques 21 studies were identified for review. Data extraction and synthesis using thematic content analysis revealed six organizing and 32 finer level themes. These related to child factors, family dynamics, parenting, knowledge and beliefs, extra‐familial influences and resources and environment. Themes were mapped to a socioecological model which illustrated how factors at individual, interpersonal, community, organizational and societal levels interact in complex ways to impact on parental perceptions about healthy behaviours for preventing child overweight. Although parents suggested several ideas to promote healthy child weight‐related behaviours, many of their views concerned perceived barriers, some of which may be amenable to practical intervention. Furthermore, intergenerational influences on parental health beliefs and knowledge suggest that health promotion strategies may be more effective if directed at the wider family, rather than parents alone. Significantly, many parents believed strategies to promote healthy weight should start early in a child's life.     

Disease and gender-specific dysregulation of NGAL and MMP-9 in type 1 diabetes mellitus

Neutrophil gelatinase-associated lipocalin (NGAL), a biomarker of renal injury, can bind matrix metalloproteinase-9 (MMP-9) and inhibit its degradation, thereby sustaining MMP-9 proteolytic activity. MMP-9 is produced by renal podocytes, and podocyte MMP production can be modified by high ambient glucose levels. Moreover, dysregulation of MMP-9 activity, gene expression, or urine concentrations has been demonstrated in T2DM-associated nephropathy and in non-diabetic proteinuric renal diseases. Our objective was to determine whether NGAL/MMP-9 dysregulation might contribute to or serve as a biomarker of diabetic nephropathy in type 1 DM (T1DM). Plasma MMP-9, and urine NGAL and MMP-9 concentrations were measured in 121 T1DM and 55 control subjects and examined relative to indicators of glycemia, renal function, and degree of albuminuria. T1DM was associated with a significant increase in urinary excretion of both NGAL and MMP-9, and urine NGAL:Cr (NGAL corrected to urine creatinine) and urine MMP-9:Cr concentrations were highly correlated with each other. Both were also positively correlated with measurements of glycemic control and with albuminuria. Plasma MMP-9, urine MMP-9, and urine NGAL concentrations were significantly higher in females compared to males, and urine MMP-9:Cr concentrations displayed a menstrual cycle specific pattern. Increased urinary excretion of NGAL and MMP-9 supports a role for NGAL/MMP-9 dysregulation in renal dysfunction; moreover, gender-specific differences could support a gender contribution to pathological mechanisms or susceptibility for the development of renal complications in diabetes mellitus.     

Association between antenatal depression and low birthweight in a developing country

OBJECTIVE: There is a high prevalence of depression in south Asian women. We aimed to examine the association between antenatal depression and low birthweight (LBW) in infants in a rural community in Rawalpindi, Pakistan. METHOD: A total of 143 physically healthy mothers with ICD-10 depression in the third trimester of pregnancy and 147 non-depressed mothers of similar gestation were followed from birth. Infant weight was measured and information collected on socioeconomic status, maternal body-mass index and sociodemographic factors. RESULTS: Infants of depressed mothers had lower birthweight (mean 2910 g) than infants of non-depressed mothers (mean 3022 g). The relative risk for LBW (< or =2500 g) in infants of depressed mothers was 1.9 (95% CI 1.3-2.9). The association remained significant after adjustment for confounders by multivariate analyses. CONCLUSION: Low birthweight is a major public health problem in developing countries. Maternal depression during pregnancy predicts LBW. Interventions aimed at maternal depression may help improve infant outcomes.     

癌症化学预防的分子靶标

乙肝病毒和人乳头状瘤病毒分别是肝细胞癌和子宫颈癌的风险因素,针对这2种病毒感染的疫苗已在临床上成功用于癌症化学预防。分子靶向药物能够预防乳腺癌（雷洛昔芬与他莫昔芬）、大肠腺瘤（塞来昔布）和前列腺癌（非那雄胺）。然而,化学预防广泛应用于临床还不现实。分子靶标的深入研究将扩展化学预防的范围并使其个性化。     

A Critical Assessment of Studies on the Carcinogenic Potential of Diesel Exhaust

After decades of research involving numerous epidemiologic studies and extensive investigations in laboratory animals, a causal relationship between diesel exhaust (DE) exposure and lung cancer has not been conclusively demonstrated. Epidemiologic studies of the transportation industry (trucking, busing, and railroad) show a small elevation in lung cancer incidence (relative risks [RRs] generally below 1.5), but a dose response for DE is lacking. The studies are also limited by a lack of quantitative concurrent exposure data and inadequate or lack of controls for potential confounders, particularly tobacco smoking. Furthermore, prior to dieselization, similar elevations in lung cancer incidence have been reported for truck drivers, and in-cab diesel particulate matter (DPM) exposures of truck drivers were comparable to ambient highway exposures. Taken together, these findings suggest that an unidentified occupational agent or lifestyle factor might be responsible for the low elevations in lung cancer reported in the transportation studies. In contrast, underground miners, many of whom experience the highest occupational DPM exposures, generally do not show elevations in lung cancer. Laboratory studies must be interpreted with caution with respect to predicting the carcinogenic potential of DE in humans. Tumors observed in rats following lifetime chronic inhalation of very high levels of DPM may be attributed to species-specific overload mechanisms that lack relevance to humans. Increased tumor incidence was not observed in other species (hamsters or mice) exposed to DPM at very high levels or in rats exposed at lower levels (≤2000 μg/m³). Although DPM contains mutagens, mutagenicity studies in which cells were exposed to concentrated extracts of DPM also have limited application to human risk assessment, because such extracts can be obtained from DPM only by using strong organic solvents, agitation, and heat. Most studies have shown that whole DPM itself is not mutagenic because the adsorbed organic compounds are minimally bioavailable in aqueous-based fluids. In the past two decades, dramatic changes in diesel engine technology (e.g., low-sulfur fuel and exhaust after-treatment) have resulted in >99% reduction in DPM and other quantitative and qualitative changes in the chemical and physical characteristics of diesel exhaust. Thus, the current database, which is focused almost entirely on the potential health effects of traditional diesel exhaust (TDE), has only limited utility in assessing the potential health risks of new-technology diesel exhaust (NTDE). To overcome some of the limitations of the historical epidemiologic database on TDE and to gain further insights into the potential health effects of NTDE, new studies are underway and more studies are planned.     

A Reevaluation of the Literature Regarding the Health Assessment of Diesel Engine Exhaust

While the International Agency for Research on Cancer (IARC) classified diesel exhaust (DE) as a “probable” carcinogen in 1989 based primarily on “sufficient” animal data, other investigators have since concluded that the lung tumors found in the rat studies were a result of particle overloading. Subsequent health risk assessments of DE have not used the rat cancer data. The U.S. Environmental Protection Agency (EPA), in developing its 2002 Health Assessment Document (HAD) for DE, primarily considered the epidemiology studies of railroad workers and truck drivers to develop health risk assessments of DE. However, both sets of epidemiology studies have serious weaknesses that make them unsuitable for cancer risk assessment. Major shortcomings were the lack of contemporaneous measurements of exposures to DE, difficulties with exposure history reconstruction, and adequately accounting for other exposures such as gasoline exhaust and cigarette smoke. To compound these problems, there was not, and there is still not, a specific exposure marker for DE. Interestingly, in the underground mining industry, where diesel exposures are much higher than observed in railroad workers and truck drivers, there was no increase in lung cancer. These problems and concerns led the U.S. EPA to conclude that while DE was a “likely” carcinogen, a unit risk value or range of risk cannot be calculated from existing data and that the risk could be zero. In addition, the DE emissions have changed and continue to change with the implementation of new emission control technologies. The HAD recognized this fact and noted that further studies are needed to assess new diesel engine emissions. Recent chemical characterization studies on low-emitting diesel engines with catalyzed particulate filters have shown emissions rates for several chemicals of concern that are even lower than comparable compressed natural gas (CNG)-fueled engines. With lower emissions, better fire safety, and improved cost-effectiveness of new low-emitting diesels compared to CNG, current efforts to restrict use of low-emitting diesels seems misguided.