脾切除对结直肠癌切除术后的影响：一项多中心、嵌入式、配对队列研究

目的探讨医源性脾脏损伤脾切除对结直肠癌切除患者术后长期生存的影响。方法对1990年1月1日至1999年12月31日10年间行结直肠癌手术切除并附带脾切除患者进行病例配对回顾研究。分析患者年龄、性别、依据美国麻醉学医师协会（ASA）标准评估的身体状况、疾病分期、手术类型及预后等资料。配对病例来自同一医疗中心，性别、年龄、疾病分期及手术类型完全相同。手术附带脾切除患者为试验组，未切脾者为对照组。结果55例患者行医源性脾切除术，对照组在年龄、性别、身体状况、疾病分期及手术类型上与之匹配。随访时间（从手术开始到患者死亡或者最后一次随访1为2～205个月（中位随访时间为43个月）。Cox比例危险度模型进行Kaplan-Meier法生存分析发现两组间差异有显著性意义，不切除脾脏对患者生存有利（危险度1．8，95％可信区间为1-3．3，P=0．0399），未切脾组与切脾组5年生存率分别为70％和47％，10年生存率分别为55％和38％。结论结直肠癌患者在行结肠或直肠切除时，因医源性脾脏损伤而切除脾脏者，预后较差。     

Mode of regulation of natural killer cell activity by interferon

Whereas xenogeneic tumors such as baby hamster kidney or HeLa cells grow in nude mice, the same cells persistently infected with a variety of viruses are rejected. Spleen cells from normal nude mice were found to be induced to produce interferon and to exert natural killer (NK) activity on virus persistently infected (PI) tumor cells, and not on uninfected parental cells in vitro. The phenotype of the interferon-producing cells and the NK effector cells was found to be the same namely, Qa 5(+), Ly 5(+), ganglio-N- tetraosylceramide, with 35 percent of the NK cells also expressing Thy 1.2. NK activity against virus PI tumor cell lines could be nonspecifically augmented both in vivo and in vitro by prior contact with virus PI tumor cells. It was unambiguously demonstrated with chemically homogeneous mouse interferon that interferon, and not a contaminant, was responsible for the augmentation of NK activity in vitro. Studies on the mode of interferon action in augmenting NK activity revealed that the target cell for interferon action was serologically distinct from the NK effector cell. Anti-Ly 5 + complement (C)-treated spleen cells were depleted of NK activity and the ability to produce interferon, but, upon incubation with interferon for 1-3 h, regained both NK activity and susceptibility to anti-Ly 5 + C. Treatment with anti-Qa 5 + C eliminated NK activity, which could not be restored by the addition of interferon. We conclude that interferon produced by Ly 5(+) cells in response to virus PI tumor cells acts on Ly 5(-) precursor cells and induces their differentiation into functional Ly 5(+) NK effector cells.     

Gender differences in cardiovascular risks of obese adolescents in the Bronx

Objective: The associations between the degree of obesity and cardiovascular disease (CVD) risks and the impact of gender differences with regard to these risk factors are not well understood. The aim of our study was to examine the gender−specific differences in CVD risk factors in inner−city minority youths.Methods: A total of 269 adolescents (109 males and 160 females) were included in this retrospective study. Data on multiple metabolic variables were collected. Evaluation of abnormalities in these parameters was based on standard criteria. Pearson correlations were calculated to examine the relationship between body mass index (BMI) z−score and obesity−related parameters. Chi−square and Fisher’s tests were used to compare the frequencies of single or multiple cardiovascular risks in the two gender groups.Results: In the male group, BMI z−scores showed significant positive correlations with insulin resistance and diastolic blood pressure. In the female group, BMI z−scores showed significant positive correlations with insulin resistance and systolic blood pressure. In both genders, the prevalence of CVD risks was high, but a similar risk pattern was established in both sexes, with dyslipidemia being the highest, hypertension the second, and impaired glucose tolerance (IGT) being the least outstanding. The most important finding in this study was that the male group had a significantly higher prevalence of systolic hypertension.Conclusion: Male inner−city minority adolescents show a high prevalence of CVD risks associated with obesity. Appropriate risk stratification is critical to developing and implementing both therapeutic and preventive interventions.Conflict of interest:None declared.     

Controlled release of chlorhexidine antiseptic from microporous amorphous silica applied in open porosity of an implant surface

Amorphous microporous silica (AMS) serving as a reservoir for controlled release of a bioactive agent was applied in the open porosity of a titanium coating on a Ti-6Al-4V metal substrate. The pores of the AMS emptied by calcination were loaded with chlorhexidine diacetate (CHX) via incipient wetness impregnation with CHX solution, followed by solvent evaporation. Using this CHX loaded AMS system on titanium substrate sustained release of CHX into physiological medium was obtained over a 10 day-period. CHX released from the AMS coating was demonstrated to be effective in killing planktonic cultures of the human pathogens Candida albicans and Staphylococcus epidermidis. This surface modification of titanium bodies with AMS controlled release functionality for a bioactive compound potentially can be applied on dental and orthopaedic implants to abate implant-associated microbial infection.     

Erratum to: Opsonization,Biodistribution, Cellular Uptake and Apoptosis Study of PEGylated PBCA Nanoparticle as Potential Drug Delivery Carrier

Pharmaceutical Research -     

Carryover of cigarette smoke effects on hematopoietic cytokines to F1 mouse litters

Neutrophils have been implicated in the pathogenesis of COPD, being recruited into the lung in response to cigarette smoke (CS) inhalation and responsible for the release of proteases and oxidant-producing enzymes, resulting in bronchitis and emphysema. Several hematopoietic cytokines are involved in neutrophil growth and recruitment; however, little is known about the effects of CS on hematopoietic cytokines are transmitted between generations. In the present investigation we evaluate the expression of hematopoietic and proinflammatory cytokines in different organs of female F(0) mice subjected to sub-chronic CS exposure, and in F(1) litters. Virgin female Balb/c mice inhaled either air or air containing CS for 90 days. The specific resistance of the airways (sRaw) was evaluated and, thereafter, the mice were mated with unexposed adult males. The levels of granulocyte-macrophage colony stimulating factor (GM-CSF), granulocyte-colony stimulating factor (G-CSF), interleukin-6 (IL-6), IL-1β and TNF-α mRNA and protein were evaluated in the bone marrow, amniotic fluid and bronchoalveolar lavage fluid (BALF) of F(0) dams at gestation day(14) (gd(14)) and the bone marrow, BALF and lungs of F(0) dams and F(1) littermates at post natal day(21) (pnd(21)). At gd(14), overexpression of GM-CSF, G-CSF and IL-6 mRNA and protein was observed in the bone marrow, amniotic fluid and BALF of F(0) dams. These hematopoietic cytokines were also overexpressed in the lungs of F(1) littermates compared with the control F(1) litters at pnd(21). Lineage-specific hematopoietic growth factors may play an important role in the transmission of neutrophil-associated disease susceptibility across generations.     

Influence of patellar ligament insertion angle on quadriceps usage during walking in anterior cruciate ligament reconstructed subjects

Reduced quadriceps contraction has been suggested as an adaptation to prevent anterior tibial translation in anterior cruciate ligament (ACL)-deficient knees. This theory has been supported by a recent study that peak knee flexion moment (thought to be created by a decrease of quadriceps contraction) during walking was negatively correlated with patellar ligament insertion angle (PLIA) in ACL-deficient knees, but not in contralateral, uninjured knees. In addition, the PLIA was significantly smaller in ACL-deficient knees than in contralateral, uninjured knees. However, it is unknown whether ACL reconstruction restores the PLIA or whether the relationship between the PLIA and knee flexion moments previously observed in ACL-deficient knees disappears. This study tested the following hypotheses: (1) The PLIA of ACL-reconstructed knees is significantly smaller than the PLIA of uninjured contralateral knees; (2) Peak knee flexion moment (balanced by net quadriceps moment) during walking is negatively correlated with the PLIA in ACL-reconstructed knees. The PLIA of 24 ACL-reconstructed and contralateral knees were measured using MRI, and peak knee flexion moments during walking were measured. Results showed that the PLIA of ACL-reconstructed (22.9 ± 4.4°) knees was not significantly smaller (p = 0.09, power = 0.99) than the PLIA of contralateral (24.1 ± 4.8°) knees. Peak knee flexion moment was not correlated with the PLIA following ACL reconstruction (R² = 0.016, power = 0.99). However, the magnitude of the knee flexion moment remained significantly lower in ACL-reconstructed knees. In summary, this study has shown that the PLIA of ACL-reconstructed knees returned to normal and that patients no longer adapt their gait in response to the PLIA, though quadriceps function did not return to normal levels. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 730–735, 2009     

Hepatitis B Immunisation in Health Care Workers

Background

Hepatitis B virus (HBV) infection is an important occupational risk in health care workers (HCW). In spite of HBV vaccine availability in Armed Forces, the high prevalence of HBV infection in HCW continues to be a problem. The study was undertaken to study the HBV vaccine-compliance among HCW.

Methods

A cross-sectional study was conducted at a tertiary care hospital. HCW were requested to fill up the pre set questionnaire to assess the HBV vaccination coverage.

Result

Amongst 254 HCW, only 57.7% were vaccinated against HBV. The vaccine compliance was lowest among housekeeping professionals. The mean age at vaccination was high (30.5 years). Amongst the vaccine non-compliant subjects, 34.3% were above 30 years of age. 32.2% HCW completed primary vaccination after spending more than 10 years in the profession. Accessibility of HBV vaccine, knowledge and perception of HBV risk were important factors in vaccine non-compliance.

Conclusion

Due to low and delayed HBV vaccine-compliance, HCW continue to be at the risk of occupational HBV. Health education highlighting occupational risk of HBV, accessibility of vaccine and mandatory vaccination of HCW is recommended to increase HBV vaccine compliance among HCW.Key Words: Health care workers, Hepatitis B virus, Occupational risk, Hepatitis B vaccine     

Azurin-like protein blocks invasion of Toxoplasma gondii through potential interactions with parasite surface antigen SAG1

Some pathogenic bacteria produce factors that have evolved a capacity to neutralize competing microbes. The cupredoxin family protein azurin, produced by Pseudomonas aeruginosa, exhibits a remarkable ability to impede invasion of a number of diverse intracellular pathogens, including the human AIDS virus human immunodeficiency virus type 1 and the protozoan parasite Plasmodium falciparum (which causes malaria). Here we report that azurin and an azurin-like protein (Laz) from gonococci/meningococci have activity against Toxoplasma, an apicomplexan parasite that causes opportunistic infection in immunocompromised individuals. We demonstrate that the mechanism of action for Laz involves interfering with the ability of Toxoplasma to adhere to host cells. Computer structural analysis reveals that azurin shares structural features with the predominant surface antigen SAG1, which is known to play an important role in parasite attachment. Interestingly, azurin also has structural similarities to a monoclonal antibody to SAG1. Surface plasmon resonance binding studies validate that SAG1 interacts strongly with Laz and, to lesser extent, azurin. Moreover, Toxoplasma mutants lacking SAG1 are not as susceptible to the growth-inhibitory effects of Laz. Collectively, our data show that Toxoplasma adhesion can be significantly impaired by Laz, and to some extent by azurin, via interactions with SAG1. These observations indicate that Laz can serve as an important tool in the study of host-pathogen interactions and is worthy of further study for development into potential therapeutic agents.