Association of SV40 with human tumours

SV40 was discovered as a contaminant of poliovirus vaccines that were inadvertently administered to millions of people in Europe and the United States between 1955 and 1963. Shortly afterwards, SV40 was proven to be oncogenic in rodents and capable of transforming human and animal cells in vitro. The possibility that SV40 might cause tumours in humans thus became a subject of scientific and public interest and scrutiny. However, largely due to a lack of significant epidemiological evidence, interest in assessing SV40's potential carcinogenic role in humans diminished. Recently, many laboratories have reported the presence of SV40-like DNA in a high proportion of human mesotheliomas, ependymomas and osteosarcoma (the three main types of tumours caused by virus in hamsters), renewing the question whether SV40 might be a human tumour virus. Molecular data from these studies are reviewed to re-evaluate the potential role of SV40 as a human carcinogen.

Mitral valve repair and transesophageal echocardiographic findings in a high-risk subgroup of patients with active, acute infective endocarditis

BACKGROUND AND AIM OF THE STUDY

Limited data are available regarding the efficacy of mitral valve repair in patients affected by active, acute infective endocarditis. In addition, the predictivity of transesophageal echocardiography (TEE) for guiding the surgical decision-making process in these patients has not yet been reported. The study aim was to evaluate the long-term results of mitral valve repair and role of TEE in active, acute infective endocarditis.

METHODS

The study population consisted of patients affected by infective endocarditis of the mitral valve who underwent surgery. TEE was performed intraoperatively to guide the best surgical approach. All patients were followed up (mean 73+/-8 months) after surgery.

RESULTS

Twenty-eight patients underwent surgery for infective endocarditis; of these, 13 had mitral valve repair for active, acute infective endocarditis and formed the basis of the study. Sensitivity, specificity, positive predictive value, negative predictive value of TEE in detecting the mechanism of mitral regurgitation were 87%, 100%, 100% and 92%, respectively. The predictivity test of TEE in guiding surgical strategy was 94%. All patients were alive at the time of follow up; 10 (77%) were in NYHA class I and three in class II (23%). Mitral regurgitation was severe in one patient (8%), moderate in three (23%), mild in four (31%), and absent in five (38%). No relapses of active infective endocarditis were observed during the follow up period.

CONCLUSION

Mitral valve repair appears to be an effective treatment for active, acute infective endocarditis with mitral regurgitation and should be considered as a therapeutic strategy when surgery is contemplated. TEE has a fundamental role in the surgical decision-making process in these patients.

Prognostic significance of presence and reduplication of basal lamina in malignant pleural mesothelioma

The prognosis of patients with malignant pleural mesothelioma (MM) is dependent more on tumor extension and differentiation than on therapeutic effects. Reduplication of the basal lamina (RBL) is an ultrastructural feature of some benign and malignant tumors that has been inversely correlated with aggressiveness and was recently described in MM. To investigate whether RBL is important for predicting the survival of patients with MM, transmission electron microscopy was used to identify the presence of basal lamina or RBL in biopsy specimens obtained by thoracoscopy from 35 patients. Cox's regression analysis was used to study the relation of these ultrastructural features to survival. Better outcomes were found for patients whose tumors expressed either basal lamina (HR 0.48; 95% CI, 0.09-2.47) or RBL (HR 0.38; 95% CI 0.12-1.22) compared with the reference category, where basal lamina or RBL was not found. The expression of basal lamina and RBL is an important novel prognostic factors in MM. HUM PATHOL 31:1341-1345.

Simian virus-40 sequences are a negative prognostic cofactor in patients with malignant pleural mesothelioma

Several biochemical and clinical factors have been shown to correlate with survival in human malignant pleural mesothelioma (MM). Nevertheless, average survival of 4 to 10 months from diagnosis is sometimes not sufficient for full expression of these factors. Several studies have reported SV40 sequences in MM, suggesting a possible pathogenic role. We investigated whether the presence of these sequences had any effect on MM patient survival. For this study, we used polymerase chain reaction and Southern blot analysis to search for and identify SV40 DNA in biopsy samples from 83 MM patients. These cases were divided according to histology: 62/83 (74. 7%) had epithelioid morphology (EMM) and 21/83 (25.3%) had either biphasic or sarcomatous morphology (B/SMM). SV40 positivity was significantly associated with B/SMM growth pattern (chi-squared test = 5.03, P = 0.025). Kaplan-Meier univariate analysis confirmed the independent effect of histology on MM survival (log-rank test = 13.9, P < 0.001) and showed a trend for increased survival in SV40-negative patients (log-rank test = 2.83, P = 0.09). Most importantly, Cox's regression model showed that SV40-positive status affected the predictive value of histology on patient survival. In particular, when SV40 expression was added to the B/SMM histotype, Cox's regression model showed a significant increase in hazard ratio (HR) with respect to SV40-negative B/SMM (HR = 4.25, 95% CI = 2.00-9. 00, likelihood ratio test = 14.31, P < 0.001). We conclude that SV40 expression is significantly associated with B/SMM histology and represents an important prognostic cofactor when associated with the tumor subtype in MM patients.

[Bact-Alert system for hemocultures: evaluation of terminal subcultures]

Few laboratory microbiological procedures are as important as the isolation of microorganisms from blood. To evaluate the usefulness of the terminal subcultures, 5669 blood cultures giving negative results after 7 days of incubation in the Bact/Alert System (Organon Teknika) were studied. Bottles were distributed as follows: 1562 adult aerobic bottles, 119 adult anaerobic bottles, 3960 pediatric bottles and 28 FAN bottles. From 5669 blood cultures, 10 subcultures that yielded growth had not been detected by the system. These included 5 adult aerobic bottles and 5 pediatric bottles, 7 of these microorganisms were considered contaminants according to clinical data (2 Micrococcus spp, 1 staphylococci coagulase negative, 1 Burkholderia cepacia, 1 Peptoestreptococcus spp, 1 Corynebacterium spp, 1 Scedosporium spp) while the other 3 were considered true bacteremia (1 Pseudomonas aeruginosa, 1 Proteus mirabilis, 1 Streptococcus sanguis), although no one made any change in treatment on the basis of the previous isolation. Based on these results the routinary utilization of terminal subcultures is not advisable and should be used only for special cases or a second system of blood culture should be added according to clinical or epidemiological data.

Interleukin-2 induces cell cycle perturbations leading to cell growth inhibition and death in malignant mesothelioma cells in vitro

Previous report indicated that Interleukin-2 (IL-2) is able to inhibit the growth of IL-2-receptor-positive cancer cell lines without any involvement of the immune system, through IL-2-induced alterations of the cell cycle kinetics. In this study we provide evidence that IL-2 exerts anti-proliferative effect on three human malignant mesothelioma (MMe) cells in vitro, while no effects were observed on normal human mesothelial cell (HMC) primary cultures. The growth inhibitory effect of IL-2 on neoplastic cells appeared to depend on the baseline proliferative status of these cells. Indeed, in highly proliferating MMe cells, we observed a reduction of malignant cells in the S-phase of the cell cycle, with an accumulation in G0/G1, followed by apotosis for longer incubations or exposure to higher doses. On the contrary, in MMe cells proliferating at lower rate, IL-2 induces only a late cytotoxic effect, leading to apoptosis, without significantly affecting the cell cycle. IL-2Rbeta mRNA was detectable by RT-PCR in all MMe cells, IL-2Ralpha mRNA in one only out the three assayed and IL-2Rgamma mRNA in none. In addition, mRNA specific for the IL-2Rbeta-associated Jak-1 tyrosine kinase was expressed in all MMe cell lines, further suggesting that IL-2Rbeta may play a role in the observed effects. Very low, albeit detectable, levels of IL-2Rbeta chain appeared to be expressed at the cell surface of MMe cells by indirect immunofluorescence and FACS analyses. Finally, Ca(++) fluxes were rapidly induced when MMe cells were exposed to exogenous IL-2.

Adenovirus-mediated wild-type p53 overexpression reverts tumourigenicity of human mesothelioma cells

Pleural malignant mesothelioma (MM) shows poor survival, regardless of tumour stage at diagnosis. MM is unresponsive to present treatment regimens and new protocols are desperately needed. The localised nature, the potential accessibility, and the relative lack of distant metastases make MM a particularly attractive candidate for somatic gene therapy. A common target for cancer gene therapy is the tumour suppressor protein p53. p53 does not seem to be mutated or deleted in MM, but it can be inactivated by binding to other proteins, like mdm2 and SV40 large T antigen. We tested the effects of a replication-deficient adenoviral vector carrying wild-type p53 cDNA in human MM cells. Our results show that >95% of MM cells were efficiently infected with 25 multiplicity of infection (MOI) of vector. Wild-type p53 was effectively expressed resulting in >80% inhibition of proliferation in MM cells. AdCMV.p53 infection induced apoptosis while controls did not show any evident morphological alterations. Ex vivo p53 gene transfer experiments inhibited tumourigenesis in nude mice. In vivo, direct intratumour injection of AdCMV.p53 arrested tumour growth and prolonged survival of treated mice. These results indicate that p53-gene therapy should be strongly exploited for clinical trials in MM patients.

[Left atrial myxoma. Clinical and surgical features in 26 surgically treated cases]

BACKGROUND

Left atrial myxomas are the most common benign intracardiac tumors. The aim of this study was to compare our experience with the data reported in the literature.

METHODS

Between May 1985 and August 1999, 26 patients (8 males, 18 females) with left atrial myxomas underwent surgical resection of these tumors at the Department of Cardiac Surgery, Ospedali Riuniti of Bergamo (Italy). Symptoms included congestive heart failure, dyspnea, arrhythmias, chest pain and syncope. Diagnosis was established preoperatively in all patients by echocardiography and angiocardiography was performed in 8 cases. All tumors were excised with a wide margin of uninvolved atrial septum. Two patients underwent concomitant coronary artery bypass.

RESULTS

There was 1 early death due to irreversible ventricular fibrillation. Follow-up was completed for the 25 late survivals. Three patients died, years after operation, due to extracardiac causes. One patients had recurrence of the tumor, which was successfully removed 4 years after initial operation. All other patients are asymptomatic and free from disease.

CONCLUSIONS

Operation for left atrial myxoma can be undertaken solely on the basis of echocardiographic findings, but coronary angiography should be performed in older patients who are at risk for coronary artery disease. Surgical excision of left atrial myxomas must be performed as soon as possible after diagnosis is established because of the high risk of valvular obstruction or systemic embolization. Biatrial approach allows for the inspection of the four cardiac chambers, limits manipulation of the mass, and facilitates the complete excision of the tumor. Thus, surgical intervention can be curative for patients with left atrial myxomas and most of these can expect an excellent outcome. Since late recurrence, although rare, has been reported, especially in familial myxomas, long-term clinical and echocardiographic follow-up is recommended.

SV40, JC and BK expression in tissue, urine and blood samples from patients with malignant and nonmalignant pleural disease

BACKGROUND

Polyomaviruses are expressed in both human tumors and immunodepressed patients. Malignant and nonmalignant pleural effusions create an environment that could favor the expression of opportunistic viral infections. We studied if SV40, JC, and BK viral DNA can be amplified from biopsies obtained from different pleural diseases.

MATERIALS AND METHODS

DNA was extracted from mesotheliomas (MM), nonspecific inflammatory and tubercular pleural biopsies, blood and urinary sediments from patients with MM, and pleural effusion cytological specimens. SV40, JC and BK viral early regions were amplified by PCR and analyzed by Southern Blot hybridization with specific probes.

RESULTS

SV40 was positive in 9/23 MM, 5/18 tubercular and 1/7 nonspecific inflammatory biopsies, and 5/12 pleural effusion cytological specimens. JC was positive in 2/23 MM and in 7/15 urinary sediments. All blood samples were negative and BK was also negative in all samples.

CONCLUSIONS

Tissue specific factors, characteristic of MM and TB, may contribute to expression of SV40 in these diseases.

Virtual freezing of the hemiacetal-aldehyde equilibrium of the aglycones of oleuropein and ligstroside present in olive oils from Carolea and Coratina cultivars by ionspray ionization tandem mass spectrometry

The composition of the equilibrium between aldehydes and hemiacetals was evaluated by ionspray ionization tandem mass spectrometry. The methanolic extracts of virgin olive oil from Carolea and Coratina cultivars contain a complex mixture of hydroxytyrosol (3) and tyrosol (4) derivatives (5, 6) characterized by the presence of aldehyde moieties in equilibrium with their hydrated form (8) or with the corresponding methanol hemiacetals 9 and 10. The equilibrium was frozen by droplet evaporation, thus allowing the structure determination of each component. The formation of the decarboxylated species 11-14, reported previously, was not observed.

[The microbiology laboratory in the diagnosis of bacteremia associated with catheters]

Catheter related sepsis is an outstanding problem in patients in every age group. The microbiological diagnosis should consider the main pathways of infection (catheter-skin interface, endoluminal). With this aim we analysed 1496 central and peripheral short term catheters and 119 episodes of catheter related bacteremia. Catheters were cultured according to the quantitative technique of Brun Buisson (QT), the semiquantitative technique of Maki (SQ) and qualitative broth culture (QL). The following results of sensitivity, specificity, positive predictive value, negative predictive value and Youden index were obtained: SQ = 87%, 88%, 40%, 99%, 0.75; QT (> or = 10(2) CFU/ml) = 88%, 89%, 43%, 99%, 0.77; QT (> or = 10(3) CFU/ml) = 77%, 92%, 48%, 97%, 0.69; QL = 94%, 68%, 20%, 99%, 0.62. Results of SQ and QT > or = 10(2) were comparable, nevertheless, the addition of QT to SQ increased the detection of bacteremia by 12.8%, while in the opposite situation the increase was 10%. According to this, it is advisable to combine routinely SQ and QT. Finally, in 42 episodes of bacteremia related to implanted catheters processed by quantitative differential culture of blood drawn through the catheter and blood drawn through the peripheral vein the relationships were: > 1000 in 79% of cases, between 100 and 1000 in 9% of cases and between 5 and 10 in just 5% of cases.

[Evaluation of the reincubation of positive blood cultures for detection in the BACT-ALERT system for the detection of polymicrobial bacteremia]

Between February and September 1997, 6588 blood cultures at the Instituto de Cardiología y Cirugía Cardiovascular and Hospital de Niños Ricardo Gutiérrez were studied by using the Bact-Alert system (Organon Teknika) 341 contaminants and 294 episodes of bacteremia (600 samples) were analyzed. From these samples, 280 (95.3%) were monomicrobial episodes and 14 (4.7%) polymicrobial episodes. Positive blood cultures detected by the Bact-Alert system were processed and then reincubated during 7 days, when they were Gram stained and subcultured in blood agar, chocolate agar (both in 5-10% CO2), laked blood agar supplemented with hemin and vitamin K in anaerobic atmosphere (only anaerobic bottles) and CLDE (aerobic conditions). Following reincubation, 3 out of 14 polymicrobial bacteremias were detected, rising the level of detection from 3.7% to 4.7%. Taking into account the total number of bacteremias, only in 3 out of 294 (1%), a second microorganism was detected. Otherwise, in blood cultures where a contaminating microorganism was initially isolated, no further isolates representing a true bacteremia were recovered. Reincubation and terminal subculture of initially positive blood cultures did not provide relevant data in order to change therapeutic measures in the studied population. Due to the increase in costs and labor we consider that this methodology is not routinely advised.

Modulation of integrin expression on mesotheliomas: the role of different histotypes in invasiveness

The in vitro and in vivo integrin expression in human pleural malignant mesothelioma (MM) of three different histotypes was studied. Cell lines from MM of epithelioid (E1), fibrous (F1), byphasic histotype (B1) and normal mesothelial cells (NM) were analysed for the surface expression of alpha2, alpha3, alpha4, alpha5, alpha6, alphav, beta1, beta3, beta4 subunits and alphavbeta5 integrins. We found that alpha6, beta4 subunits and alphavbeta5, weakly detectable on NM cells, were expressed on MM cells. The beta3 subunit, well expressed on NM cells, was absent on MM cells. Differential expression among histotypes was observed, the MM-E1 was the least and the MM-B1 the most positive. Specimens for each MM histotype, were analysed by immunohistochemistry. The alpha6 and alphav subunits were more evident on the epithelioid histotype. Intense staining for beta3 and beta4 subunits, was found in all MM, particularly in invading cells, while the alpha5, and alphavbeta5 integrins were variously expressed. The different histotypes can affect the in vitro integrin expression and may indicate a preferential involvement of some subunits in vivo during MM tumor progression.

Migration of mesothelioma cells correlates with histotype-specific synthesis of extracellular matrix

Three human pleural malignant mesothelioma cell cultures (MM) of epithelioid (E1), fibrous (F1) and byphasic (B1) histotype were studied in their synthesis of the extracellular matrix (ECM) components laminin (LM), fibronectin (FN), type IV collagen (cIV), and in their chemotactic and haptotactic migration towards the ECM produced proteins. MM-B1 showed the highest FN synthesis and release; MM-E1 produced the highest quantity of basement membrane constituents LM and cIV; MM-F1 weakly produced and released FN, LM and cIV. MM-B1 had the highest chemotactic and haptotactic motility, MM-F1 migrated toward the lowest concentration of LM while had reduced chemotactic activity toward FN and cIV; MM-E1 had the lowest migratory activity toward each ECM substrate. We demonstrated that three MM of different histotype are characterized by different ECM production and that these differences determine a variable ability of each MM to spread and migrate towards ECM substrates.

Synthesis of isoxazolidino analogues of 2',3'-dideoxynucleosides

The complete set of the 4'-aza analogues of 2',3'-dideoxynucleosides was synthesized by cycloaddition of N-tetrahydropiranyl or N-trityl methylene nitrones on suitably protected vinyl nucleobases. The convertible nucleoside approach was used in the preparation of cytosine and 5-methyl cytosine analogues.

Establishment of four new mesothelioma cell lines: characterization by ultrastructural and immunophenotypic analysis

The aim of this study was to assess the biological characteristics of four new malignant mesothelioma (MM) cell lines. Since simian virus (SV)40 sequences have been recently detected in MM, SV40 large T antigen (Tag) expression was also analysed. MM cell lines were characterized by morphological, ultrastructural and cytogenetic analysis. Expression of Tag and of relevant MM markers was studied by immunocytochemistry, surface antigens by indirect immunofluorescence and immunomodulating cytokines by enzyme-linked immunosorbent assay (ELISA). The four MM cell lines, established from pleural effusions, showed a slow proliferation rate and pleomorphic changes during culture. Cell lines expressed vimentin, cytokeratins 8 and 18, and the mesothelial antigen recognized by HBME-1 monoclonal antibody, but not carcinoembryonic antigen. Surface human leukocyte antigen (HLA)-class I and intercellular adhesion molecule (ICAM)-1 molecules were present on all the cell lines. While HLA class II and CD86 were constitutively undetectable, HLA-class II was present after interferon (IFN)-gamma stimulation. All cell lines displayed abnormal karyotypes with chromosome 6 abnormalities. Transforming growth factor (TGF)-beta2 and interleukin (IL)-6 were constitutively secreted, while tumour necrosis factor (TNF)-alpha was secreted only in response to lipopolysaccharide. Intranuclear Tag was expressed in two cell lines. The persistence of large T antigen with human leukocyte antigen class I and intercellular adhesion molecule-1 positivity may point to large T antigen as a target for cytotoxic T-lymphocyte-based immunotherapy in some malignant mesothelioma patients.

Basal lamina reduplication in malignant epithelioid pleural mesothelioma

Malignant mesothelioma of the pleura is divided in three morphological variants: epithelioid, sarcomatous, and biphasic. Histological similarities between epithelioid malignant mesothelioma (EMM) and lung adenocarcinoma are responsible for the difficult differential diagnosis. Monoclonal antibodies are useful for distinguishing the two neoplasms through immunohistochemical phenotyping, although many cases require ultrastructural characterization for definitive diagnosis. In this study, transmission electron microscopic observations of EMM were compared with those of peripheral adenocarcinoma of the lung (PAL). More specifically, the morphology of the basal lamina is described in 23 cases of EMM and 12 cases of PAL. Reduplication of the basal lamina (RBL) was found in 11 cases (48%) of EMM and in none of the PAL cases. The same cases were immunostained for type IV collagen and the localization of this basement membrane component corresponded to the areas where basal lamina was observed. Since RBL has been associated with neoplastic differentiation in other tumors, this novel feature in EMM needs to be evaluated in future prognostic studies in malignant mesothelioma of the pleura. Moreover, RBL expression in EMM may be an additional ultrastructural parameter used in the differential diagnosis between EMM and adenocarcinoma.

Recurrent chromosome 6 abnormalities in malignant mesothelioma

The long latency period between asbestos exposure and the onset of malignant mesothelioma (MM) suggests that a multistep tumorigenesis process occurs whilst the capability of asbestos fibres to interfere directly with chromosomes focuses on the critical role of the chromosomal abnormalities in this neoplasm. The aim of our study was to identify any recurrent chromosomal changes in ten primary MM cell cultures derived from pleural effusions of patients with MM from the same geographic area and environmental and/or occupational exposure to asbestos fibers. Cytogenetic analysis was performed in accordance with International System for Human Cytogenetic Nomenclature. Our results confirmed a great number of cytogenetic abnormalities in MM cells. Recurrent loss of the long arms of chromosome 6 (6q-) was the most frequent abnormality detected (four epithelial and two mixed subtypes) while, on the whole, abnormalities of chromosome 6 were found in nine out of ten cases whereas chromosome 6 was normal only in the case with fibromatous subtype. Monosomy 13 and 17 was found in five cases, monosomy 14 in four cases and 22 in three cases. Since deletion of 6q- was detected even in relatively undisturbed karyotype, we hypothesize a multistep carcinogenic process in which deletion of 6q- is an early event in the development and progression of malignant mesothelioma.

Human malignant mesothelioma of the pleura: new perspectives for diagnosis and therapy

The ability to immortalize human mesothelioma cells in vitro with simian virus (SV) 40 and the fact that SV40 induces mesotheliomas in hamsters prompted us to look for SV40 deoxyribonucleic acid (DNA) sequences in human mesotheliomas. In a previous study, we found that over half (29/48) of human malignant pleural mesotheliomas contained SV40-like sequences whereas only a few (3/47) control samples contained the same detectable sequences. The SV40 genome encodes the 90 KD nuclear large T-antigen (Tag) and the 17 KD small-t antigen (tag), responsible for SV40's transforming and oncogenic properties. These antigens block tumour suppressor gene products, such as p53. We considered the possibility of reverting this effect by adding exogenous wild-type p53 and thus restoring normal cell functions. For this purpose, we developed a recombinant adenovirus carrying complementary DNA (cDNA) for wild type p53 (AdCMV.p53) and infected mesothelioma cell lines with this virus. Inhibition of proliferation, halting of the cell cycle and massive apoptosis was observed in all mesothelioma cell lines tested. In addition, proliferation of human mesothelioma tumours into nude mice was inhibited by in vivo adenovirus-mediated p53 transgene expression. We also report preliminary evidence of expression, by immunoreactivity, of the extracellular matrix protein tenascin in human malignant pleural mesotheliomas. It was interesting to find predominant tenascin positivity at the tumour's invasive edge and in areas of tumour vascularization. This preliminary report suggests that adenovirus-mediated p53 hyperexpression counteracts transforming properties of the large T-antigen and suggests that gene therapy may be useful in treating human malignant mesothelioma.

Immunobiology and immune defense mechanisms of mesothelioma cells

Malignant mesothelioma (MM) is an aggressive tumor whose incidence is expected to rise in future years. Patients with this neoplasm have a poor prognosis. Immunotherapy has been shown to be effective in some neoplasms (e.g. melanoma), significantly improving their prognosis but we do not yet have sufficient data on the capability of MM cells to elicit an immune response. A "three step" event is required to determine an immune response: adhesion, recognition, and costimulation between the antigen presenting cells and the immunoeffector cells. Lack of one of these three steps leads to a defective immune response. The most important mechanism determining the defective immune response to the tumor cells is supposed to be the deficiency of the molecules involved in this "three step event", the release of immuno-depressant factors by the tumor cells and/or the tumor infiltrating cells and the lack of surface immunogen epitopes. Investigations on MM cells are not univocal, suggesting that, at least in some cases, an effective immune response to this neoplasm can occur. Blocking the release of immunodepressant factors by malignant mesothelioma cells and identification of effective, specific immunogen epitopes seem to be the most promising objective to achieve.

Increased levels of soluble P-selectin in hypercholesterolemic patients

BACKGROUND

Hypercholesterolemia is considered a major risk factor for the development of atherosclerosis. Enhanced lipid peroxidation and persistent platelet activation can be observed in vivo in hypercholesterolemic patients and may have pathophysiological implications in the occurrence of cardiovascular events. P-selectin may play an important role in the pathogenesis of multicellular events, including atherosclerosis. We studied the impact of hypercholesterolemia and oxidative stress on plasma levels of P-selectin.

METHODS AND RESULTS

Plasma levels of P-selectin were measured by means of an enzyme immunoassay in 20 hypercholesterolemic patients with no clinical evidence of cardiovascular disease and in 20 sex- and age-matched normocholesterolemic subjects. Hypercholesterolemic patients had higher levels of P-selectin compared with that of control subjects (98+/-61 versus 56+/-14 ng/mL; P=.001). They also displayed increased von Willebrand Factor (vWF) levels (176+/-22 versus 119+/-12%; P=.0001). A direct correlation was observed between P-selectin and LDL cholesterol levels (p=.453). Administration of vitamin E (600 mg/d for 2 weeks) to hypercholesterolemic patients significantly reduced plasma P-selectin (40%), and an inverse correlation was observed between vitamin E and P-selectin plasma levels (p=-.446).

CONCLUSIONS

Hypercholesterolemia is associated with elevated plasmatic P-selectin. Altered oxidative processes leading to endothelial dysfunction and persistent platelet activation may contribute to increased soluble P-selectin levels. P-selectin may be proposed as a marker of endothelial dysfunction in hypercholesterolemic patients.