PADGEM (GMP140) is a component of Weibel-Palade bodies of human endothelial cells

PADGEM protein (PADGEM), also known as GMP140, is a platelet alpha- granule membrane protein that is translocated to the external membrane after platelet activation. Although the biosynthesis of this protein was originally thought to be confined to megakaryocytes, the synthesis of PADGEM in endothelial cells was recently demonstrated (McEver et al: Blood 70:1974a, 1987). We now describe the subcellular localization of this protein in endothelial cells. Immunofluorescence staining of permeabilized human umbilical vein endothelial cells with KC4, a well characterized monoclonal antibody to PADGEM, showed positively stained elongated structures similar in distribution and shape to Weibel-Palade bodies. Their identity as Weibel-Palade bodies was confirmed by double label immunofluorescence using KC4 and a polyclonal antiserum to von Willebrand factor (vWf), a protein known to be specifically stored in these organelles. All Weibel-Palade bodies were found to contain PADGEM. In contrast to strong perinuclear staining produced with anti- vWf antibodies, no significant perinuclear staining was obtained with KC4, indicating that relatively little PADGEM is present in the endoplasmic reticulum and in the Golgi apparatus. In endothelial cells treated with secretagogues that stimulate vWf release the elongated structures positive for PADGEM disappeared, further identifying these structures as Weibel-Palade bodies. This observation extends the parallels between Weibel-Palade bodies and alpha-granules and suggests a possible functional association between vWf and PADGEM.     

BUILDING THE FOUNDATION OF EXCELLENCE IN HEART FAILURE NURSING

This column contains the presidential address presented during the Third Annual Meeting of the American Association of Heart Failure Nurses on June 28, 2007, in San Diego, California, titled "Building the Foundation of Excellence in Heart Failure Nursing."     

Creating a professional practice environment on a shoestring

Did you ever think, “If we just had a little money we could…”? The current health care environment is wrought with financial stressors that can be overwhelming and take up most of our time. Such stress can limit the development of a professional practice environment if you let it. How do you not only survive but thrive in this financial climate?     

Establishing phenotypic features associated with morbidity in human T-cell lymphotropic virus type 1 infection

The human T-cell lymphotropic virus type 1 (HTLV-1) is the causative agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HT). Although it is widely believed that virus infection and host immune response are involved in the pathogenic mechanisms, the role of the immune system in the development and/or maintenance of HT remains unknown. We performed an analysis of the peripheral blood leukocyte phenotype for two different subcohorts of HTLV-1-infected individuals to verify the existence of similar immunological alterations, possible laboratory markers for HT. The leukocyte population balance, the activation status of the T lymphocytes, and the cellular migratory potential of T lymphocytes, monocytes, and neutrophils were evaluated in the peripheral blood of HTLV-1-infected individuals classified as asymptomatic individuals, oligosymptomatic individuals, and individuals with HT. Data analysis demonstrated that a decreased percentage of B cells, resulting in an increased T cell/B cell ratio and an increase in the CD8+ HLA-DR+ T lymphocytes, exclusively in the HT group could be identified in both subcohorts, suggesting its possible use as a potential immunological marker for HT for use in the laboratory. Moreover, analysis of likelihood ratios showed that if an HTLV-1-infected individual demonstrated B-cell percentages lower than 7.0%, a T cell/B cell ratio higher than 11, or a percentage of CD8+ HLA-DR+ T lymphocytes higher than 70.0%, this individual would have, respectively, a 12-, 13-, or 22-times-greater chance of belonging to the HT group. Based on these data, we propose that the T cell/B cell ratios and percentages of circulating B cells and activated CD8+ T lymphocytes in HTLV-1-infected patients are important immunological indicators which could help clinicians monitor HTLV-1 infection and differentiate the HT group from the asymptomatic and oligosymptomatic groups.     

Phenotypic study of peripheral blood leucocytes in HTLV-I-infected individuals from Minas Gerais,Brazil

The human T-cell lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) associated with the HTLV-I is a well-defined clinical-pathological entity in which the virus and host immune responses contribute to the pathological mechanism. In this study, flow cytometric analysis of whole peripheral blood leucocytes (PBL) was performed to evaluate the immunological status of HTLV-I-infected individuals in an effort to better understand the role of the immune system in the development of HAM/TSP. We have evaluated three groups of infected patients including asymptomatic (AS = 18), ambulatory/oligosymptomatic (AM = 14) and hospitalized HAM/TSP individuals (HO = 42). Noninfected healthy blood donors were used for the control group (NI = 32). Our results demonstrated that the HO group presents an increased percentage of circulating T cells and a decreased percentage of B and natural killer (NK) cells, leading to the highest T/B-cell ratio in comparison with the other groups. Interestingly, while an increased percentage of activated CD4+HLA-DR+ T lymphocytes was observed in both AM and HO, only HO presented higher percentage of activated CD8+HLA-DR+ in combination with the highest CD18 surface expression. This was true for all cell populations analysed, including T lymphocytes, monocytes and neutrophils. Moreover, the HO group was distinguished by a dramatic decrease in the percentage of CD8+CD28+ lymphocytes. Taken together, these findings demonstrate a potent cellular immune activation response involving primarily CD8+ T cells that is concomitant with disease progression in HAM/TSP. We also show that an upregulation of CD18 expression, a hallmark for increased cell migratory potential, might play a critical role in the development/maintenance of HAM/TSP.     

Dibenzo[a,l]pyrene-induced DNA adduction, tumorigenicity, and Ki-ras oncogene mutations in strain A/J mouse lung

Dibenzo[a,l]pyrene (DB[a,l]P), an environmental polycyclic aromatic hydrocarbon, is the most potent carcinogen ever tested in mouse skin and rat mammary gland. In this study, DB[a,l]P was examined for DNA adduction, tumorigenicity, and induction of Ki-ras oncogene mutations in tumor DNA in strain A/J mouse lung. Groups of mice received a single i.p. injection of 0.3, 1.5, 3.0, or 6.0 mg/kg DB[a,l]P in tricaprylin. Following treatment, DNA adducts were measured at times between 1 and 28 days, while tumors were counted at 250 days and analyzed for the occurrence of point mutations in codons 12 and 61 of the Ki-ras oncogene. DB[a,l]P in strain A/J mouse lung induced six major and four minor DNA adducts. Maximal levels of adduction occurred between 5 and 10 days after injection followed by a gradual decrease. DB[a,l]P-DNA adducts in lung tissue were derived from both anti- and syn-11,12- dihydroxy-13,14-epoxy- 11,12,13,14-tetrahydrodibenzo[a,l]pyrene (DB[a,l]PDE) and both deoxyadenosine (dAdo) and deoxyguanosine (dGuo) residues in DNA as revealed by cochromatography. The major adduct was identified as a product of the reaction of an anti-DB[a,l]PDE with dAdo in DNA. DB[a,l]P induced significant numbers of lung adenomas in a dose- dependent manner, with the highest dose (6.0 mg/kg) yielding 16.1 adenomas/mouse. In tricaprylin-treated control animals, there were 0.67 adenomas/mouse. Based on the administered dose, DB[a,l]P was more active than other environmental carcinogens including benzo[a]pyrene. As a function of time-integrated DNA adduct levels, DB[a,l]P induced lung adenomas with about the same potency as other PAHs, suggesting that the adducts formed by DB[a,l]P are similar in carcinogenic potency to other PAHs in the strain A/J mouse lung model. Analysis of the Ki- ras mutation spectrum in DB[a,l]P-induced lung tumors revealed the predominant mutations to be G-->T transversions in the first base of codon 12, A-->G transitions in the second base of codon 12, and A-->T transversions in the second or third base of codon 61, concordant with the DNA adduct profile.      

幽门螺杆菌中国菌株致病相关基因cagA、iceA、vacA及HP0519分布分析

目的分析中国不同人群及不同胃部疾病病例来源的幽门螺杆菌致病相关基因cagA、iceA、vacA及HP0519的分布.方法采用特异引物聚合酶链式反应（PCR）方法分析150株幽门螺杆菌上述基因的多态性分布特点,并对其分布作初步统计分析.结果93%（139/150）中国菌株cagA基因3′端重复序列的PCR产物具有东方菌株特征.75%（113/150）菌株iceA基因为iceA1,19%（29/150）为iceA2,不同地区间iceA基因的分布差异无统计学意义.云南菌株iceA1、iceA2的分布与菌株分离个体的种族特点及临床疾病类型无显著关系.96%中国菌株（144/150）vacA基因s区的等位基因为s1;m区等位基因m2、m1b和m1b-m2的比例分别为57%（85/150）、27%（41/150）和11%（16/150）,仅2株福建菌株为m1a.不同地区间vacA s1、m2、m1b分布的差异无统计学意义.云南菌株m1b-m2的分布高于福建和北京菌株.云南菌株vacA s区等位基因的多样性与分离个体的种族及临床疾病类型无显著关系.vacA m区等位基因的多样性与分离个体的临床疾病类型无显著关系,但不同民族间m2的分布有显著差异,白族人群m2的分布显著少于汉族和纳西族.93%（140/150）的中国菌株HP0519基因具有24 bp和15 bp DNA插入和缺失的多态性特点.不同地区间HP0519基因的多态性无显著不同.云南菌株HP0519的多态性与菌株分离个体的临床疾病类型无显著关系,但来源不同民族菌株的HP0519基因存在差异.结论幽门螺杆菌中国菌株cagA 3′端JF/TR特异引物的扩增结果具有东亚菌株特点.中国菌株vacA基因多为s1,其分布与菌株分离个体的临床疾病类型无关.中国菌株vacA基因m区的分布具有多样性.中国菌株HP0519基因具有24 bp和15 bp插入和缺失的多态性特点.