Biomedical subjects

C Xie

Publications and source records attributed to C Xie.

At least 19 recordsLinked to original sources

PubMed2006

Development and evaluation of a multiplex RT-PCR for detecting main viruses and a viroid of potato.

A multiplex RT-PCR (mRT-PCR) for detecting four potato viruses (Potato virus S (PVS), Potato virus X (PVX), Potato virus Y (PVY), and Potato leaf roll virus (PLRV)) and one potato viroid (Potato spindle tuber viroid (PSTVd)) was developed. The mRT-PCR consisted of one reaction with specific primers designed according to the sequences of coat protein (CP) genes of respective viruses and the sequence of the viroid. The entire procedure from tissue grinding to RT-PCR results takes about 4 hrs. The reliability of the method was tested on leaves sampled from the field, greenhouse and in vitro-grown plants by comparison with double-antibody sandwich ELISA (DAS-ELISA). A high correlation between these two methods was observed. The mRT-PCR was also evaluated by testing infected samples obtained from the International Potato Center, Lima, Peru; this testing confirmed its high reliability and sensitivity.

Capsid Proteins↗

PubMed2005

Identification of single bacterial cells in aqueous solution using confocal laser tweezers Raman spectroscopy.

We report on a rapid method for reagentless identification and discrimination of single bacterial cells in aqueous solutions using a combination of laser tweezers and confocal Raman spectroscopy (LTRS). The optical trapping enables capturing of individual bacteria in aqueous solution in the focus of the laser beam and levitating the captured cell well off the cover plate, thus maximizing the excitation and collection of Raman scattering from the cell and minimizing the unwanted background from the cover plate and environment. Raman spectral patterns excited by a near-infrared laser beam provide intrinsic molecular information for reagentless analysis of the optically isolated bacterium. In our experiments, six species of bacteria were used to demonstrate the capability of the confocal LTRS in the identification and discrimination between the diverse bacterial species at various growth conditions. We show that synchronized bacterial cells can be well-discriminated among the six species using principal component analyses (PCA). Unsynchronized bacterial cells that are cultured at stationary phases can also be well-discriminated by the PCA, as well as by a hierarchical cluster analysis (HCA) of their Raman spectra. We also show that unsynchronized bacteria selected from random growth phases can be classified with the help of a generalized discriminant analysis (GDA). These findings demonstrate that the LTRS may find valuable applications in rapid sensing of microbial cells in diverse aqueous media.

Bacteria↗

PubMed2005

Increased oxidative damage in nuclear and mitochondrial DNA in Alzheimer's disease.

Increasing evidence suggests that oxidative stress is associated with normal aging and several neurodegenerative diseases, including Alzheimer's disease (AD). Here we quantified multiple oxidized bases in nuclear and mitochondrial DNA of frontal, parietal, and temporal lobes and cerebellum from short postmortem interval AD brain and age-matched control subjects using gas chromatography/mass spectrometry with selective ion monitoring (GC/MS-SIM) and stable labeled internal standards. Nuclear and mitochondrial DNA were extracted from eight AD and eight age-matched control subjects. We found that levels of multiple oxidized bases in AD brain specimens were significantly (p < 0.05) higher in frontal, parietal, and temporal lobes compared to control subjects and that mitochondrial DNA had approximately 10-fold higher levels of oxidized bases than nuclear DNA. These data are consistent with higher levels of oxidative stress in mitochondria. Eight-hydroxyguanine, a widely studied biomarker of DNA damage, was approximately 10-fold higher than other oxidized base adducts in both AD and control subjects. DNA from temporal lobe showed the most oxidative damage, whereas cerebellum was only slightly affected in AD brains. These results suggest that oxidative damage to mitochondrial DNA may contribute to the neurodegeneration of AD.

Aged↗

PubMed2003

Reduction of soliton phase jitter by in-line phase conjugation.

The main impairment of differential-phase-shift-keyed communication systems is phase jitter. Noise-induced phase jitter, which is mediated by self-phase modulation, can be reduced significantly by a small number of in-line phase conjugators.

Journal Article↗

PubMed2003

Effects of cross-phase modulation on phase jitter in soliton systems with constant dispersion.

In wavelength-division-multiplexed communication systems phase jitter is driven by amplifier noise and mediated by cross-phase modulation. The variational method is used to derive formulas for the absolute phase variance of an ensemble of solitons and the relative phase variance of ensembles of neighboring solitons. The predictions of these formulas are consistent with the results of numerical simulations.

Journal Article↗

PubMed2003

T-bet expression is upregulated in active Behçet's disease.

AIM: To investigate T-bet mRNA and protein expression on peripheral blood mononuclear cells (PBMC) in patients with Behçet's disease with active uveitis. METHODS: Blood samples were taken from 24 patients with Behçet's disease who had active uveitis and 16 healthy individuals. PBMC were subjected to analysis of T-bet mRNA and protein expression using semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and western blot, respectively. The products from PCR were sequenced. In order to determine the influence of activation on T-bet expression, the phytohaemagglutinin (PHA) stimulated PBMC from each sample were also evaluated for expression of T-bet mRNA and protein. RESULTS: A significantly increased T-bet mRNA accumulation was detected in the samples from patients with active Behçet's disease compared with that in controls. A 62 kDa band was detectable in patients with active Behçet's disease, but not in controls. No difference was found between patients with Behçet's disease who had active uveitis and normal controls concerning the expression of either T-bet mRNA or its protein after stimulation with PHA for 72 hours. CONCLUSION: Behçet's disease is associated with an upregulation of T-bet expression, which supports a role for the Th1 subset of T cells in the pathogenesis of this disease.

Adult↗

PubMed2002

Neurodegeneration in the Niemann-Pick C mouse: glial involvement.

A mouse model of Niemann-Pick type C disease has been found that exhibits neuropathology similar to the human condition. There is an age-related neurodegeneration in several brain regions and a lack of myelin in the corpus callosum in these mice. The purpose of the present study was to examine the Niemann-Pick mouse and determine whether: (1) microglia and astrocytes exhibit ultrastructural pathology similar to that found in neurons; (2) nerve fiber number is reduced when the myelin sheath is absent; and (3) the lysosomal hydrolase, cathepsin-D, is involved in the neurodegenerative process. Using light and electron microscopic methods, and immunocytochemistry, Niemann-Pick and control animals were examined at several ages. Cathepsin-D content was semi-quantitatively measured in neurons and glial cells in brain regions known to exhibit neurodegeneration, as was the density of glial fibrillary acidic protein-labeled astrocytes. The Niemann-Pick mouse exhibited: (1) an age-related increase in inclusion bodies in microglia and astrocytes, similar to that observed within neurons; (2) an almost complete absence of myelin in the corpus callosum by 7-8 weeks of age, along with a 30% reduction in the number of corpus callosum axons; (3) a mild age-related increase in cathepsin-D content within nerve cells in many brain regions. However, the cathepsin-D elevation was greatest in microglial cells; (4) an age-related increase in the number of microglial cells containing intense cathepsin-D immunoreactivity in both the thalamus and cerebellum. Both of these brain regions have been shown previously to exhibit an age-related loss of neurons; and (5) an increase in the number of reactive astrocytes immunostained for glial fibrillary acidic protein, especially in the thalamus and cerebellum. These data indicate that glial cells are a major target for pathology in the Niemann-Pick mouse. The lack of myelin within the corpus callosum may be related to the loss of nerve fibers in this structure. The increase in cathepsin-D-laden microglial cells, in brain regions previously shown to undergo neurodegeneration, is consistent with a role for microglia in the phagocytosis of dead neurons and in actively contributing to the neurodegenerative process. The activation of astrocytes in regions that undergo neurodegeneration is also consistent with a role for these glial cells in the neurodegenerative process.

Animals↗

PubMed2001

Expression of glutathione-S-transferase isozyme in the SY5Y neuroblastoma cell line increases resistance to oxidative stress.

Glutathione-S-transferases (GSTs) are a superfamily of enzymes that function to catalyze the nucleophilic attack of glutathione on electrophilic groups of a second substrate. GSTs are present in many organs and have been implicated in the detoxification of endogenous alpha, beta unsaturated aldehydes, including 4-hydroxynonenal (HNE). Exogenous GST protects hippocampal neurons against HNE in culture. To test the hypothesis that overexpression of GST in cells would increase resistance to exogenous or endogenous HNE induced by oxidative stress, stable transfectants of SY5Y neuroblastoma cells with GST were established. Stable GST transfectants demonstrated enzyme activities 13.7 times (Clone 1) and 30 times (Clone 2) higher than cells transfected with vector alone. GST transfectants (both Clones 1 and 2) demonstrated significantly (p <.05) increased resistance to ferrous sulfate/hydrogen peroxide (20.9% for Clone 1; 46.5% for Clone 2), amyloid beta-peptide (12.2% for Clone 1; 27.5.% for Clone 2), and peroxynitrite (24.3% for Clone 1; 43.9% for Clone 2), but not to exogenous application of HNE in culture medium. GST transfectants treated with 1,1,4-tris (acetyloxy)nonane, a nontoxic derivative of HNE that is degraded to HNE intracellularly, demonstrated a statistically significant (p <.05) increase in viability in a dose-dependent manner compared with SY5Y cells transfected with vector alone. These results suggest that overexpression of GST increases resistance to endogenous HNE induced by oxidative stress or released in the degradation of 1,1,4-tris (acetyloxy)nonane, but not to exogenous application of HNE.

Aldehydes↗

PubMed2001

Selective neurodegeneration, without neurofibrillary tangles, in a mouse model of Niemann-Pick C disease.

The BALB/c mouse model of Niemann-Pick type C (NPC) disease exhibits neuropathological similarities to the human condition. There is an age-related cerebral atrophy, demyelination of the corpus callosum, and degeneration of cerebellar Purkinje cells in the NPC mouse. In human NPC, many cortical and subcortical neurons contain neurofibrillary tangles, which are thought by some investigators to play an important role in the neurodegenerative process. The purpose of the present study was to determine whether neurodegeneration occurs in the NPC mouse, in brain regions other than the cerebellum and whether the degeneration is related to the presence of neurofibrillary tangles. Using light microscopic methods with immunohistochemistry, electron microscopy, and cell counting methods, 11-week-old NPC(+/+) and NPC(-/-) animals were examined. In the NPC(-/-) mice, there were 96% fewer Purkinje cells, 28% fewer neurons in the prefrontal cortex, 20% fewer neurons in the thalamus, and 63% fewer glial cells in the corpus callosum. On the other hand, previous studies indicate normal numbers of neurons and glial cells in these same neuroanatomical regions in young NPC(-/-) mice. There were normal numbers of cholinergic neurons in sections assessed in the striatum and basal forebrain in the 11-week-old animals and no evidence of neurofibrillary tangles within cells. The present data indicate that both neurons and glial cells die in the NPC mouse but that all cells are not equally vulnerable. There was no evidence for neurofibrillary tangles in the NPC mouse, and therefore the degenerative process in the mouse is unrelated to the neurofibrillary tangle.

Animals↗

PubMed2001

Size effects of realgar particles on apoptosis in a human umbilical vein endothelial cell line: ECV-304.

Regulation of endothelial cell apoptosis is a critical modulator of normal and pathological angiogenesis. Inorganic arsenic, especially arsenic trioxide, has been demonstrated to induce clinical remission in patients with acute promyelocytic leukemia as well as those with several solid cancers. So, in this study, we examined the in vitro effect of realgar(As2S2), used to treat human diseases for centuries in traditional Chinese medicine, on cell survival and apoptosis in a human umbilical vein endothelial cell (HUVEC) line: ECV-304. Four different suspensions of realgar particles with diameters from 100-500 nm containing equivalent doses were investigated to determine their size effects. After 2, 4, 6 and 8 h, realgar particles of diameters 100 nm and 150 nm obviously reduced ECV-304 cell survival, which was evidenced by a reduction of cell viability in the MTT assay, whereas cells exhibited slight viability reduction in response to treatment with realgar particles of diameters 200 nm and 500 nm. Significant apoptosis was identified by morphological observation, flow cytometry assay and DNA gel electrophoresis in the ECV-304 cells by the presence of realgar particles of diameters 100 nm and 150 nm. It is demonstrated that particles of realgar with average diameters from 100 nm to 150 nm can induce ECV-304 cell apoptosis. These results suggest that particles of realgar smaller than 150 nm may provide a less toxic agent for anti-neoplasia by suppressing angiogenesis.

Acridine Orange↗

PubMed2001

Degeneration of neurons and glia in the Niemann-Pick C mouse is unrelated to the low-density lipoprotein receptor.

The BALB/c mouse model of Niemann-Pick type C disease exhibits similar neuropathological features to the human condition, including cerebral atrophy, demyelination of the corpus callosum, and degeneration of cerebellar Purkinje cells. The gene defect in Niemann-Pick C disease causes cholesterol to accumulate within the lysosomal compartment of neurons and glial cells. In order to determine whether cholesterol accumulation through the low-density lipoprotein receptor pathway plays an important role in the degenerative process, Niemann-Pick C mice were crossed with low-density lipoprotein receptor knockout mice. The purpose of the present study was to determine whether degeneration of neurons and glial cells is reduced in Niemann-Pick C animals lacking the low-density lipoprotein receptor. Using stereological counting methods, Purkinje cells were counted in the cerebellum and glial cell bodies were counted in the corpus callosum in mice at 3, 7.5 and 11 weeks of age. In the Niemann-Pick C animals, compared to wild-type control mice, there were 48% fewer glial cells at 3 weeks of age, and by 11 weeks of age there were 63% fewer glial cells. Purkinje cells were decreased in number by 13% at 3 weeks of age, and by 11 weeks of age there was a 96% loss. In the Niemann-Pick C animals lacking low-density lipoprotein receptors, there was no difference in the magnitude of glial cell or Purkinje cell loss compared to the Niemann-Pick C animals. These data indicate that both neurons and glia are vulnerable to degeneration in the Niemann-Pick C mouse, but that blocking the accumulation of cholesterol through the low-density lipoprotein receptor pathway does not alter the degenerative phenotype of Niemann-Pick C disease.

Animals↗

PubMed2001

Alpha-1-antitrypsin and a broad spectrum metalloprotease inhibitor, RS113456, have similar acute anti-inflammatory effects.

There is increasing evidence that antiproteases are able to affect the inflammatory response. To further examine this question, we administered human alpha-1-antitrypsin (alpha1AT) or a synthetic metalloprotease inhibitor (RS113456) to C57 mice followed by a single intratracheal dose of quartz, a dust that evokes a marked, lasting, polymorphonuclear leukocyte (PMN) infiltrate. At 2 hours after dust administration, both antiproteases completely suppressed silica-induced PMN influx into the lung and macrophage inflammatory protein-2 (MIP-2)/monocyte chemotactic protein-1 (MCP-1) (neutrophil/macrophage chemoattractant) gene expression, partially suppressed nuclear transcription factor kappaB (NF-kappaB) translocation, and increased inhibitor of NF-kappaB (IkappaB) levels. By 24 hours, PMN influx and connective tissue breakdown measured as lavage desmosine or hydroxyproline were still at, or close to, control levels after antiprotease treatment, and increases in NF-kappaB translocation and MIP-2/MCP-1 gene expression were variably suppressed. At both time points, neither agent prevented silica-induced increases in amount of whole lung MIP-2 or MCP-1 protein, but both did prevent increases in whole lung intercellular adhesion molecule-1 (ICAM-1) at 24 hours. Inactivating the alpha1AT by oxidation to the point that it no longer possessed antiproteolytic properties did not affect its ability to suppress inflammation. Both antiproteases also prevented the silica-induced acute inflammatory response in mice with knocked out genes for macrophage metalloelastase (MME -/-), mice that develop inflammation, but not connective tissue breakdown, and the pattern of alpha1AT breakdown fragments was identical in control and MME -/- animals. These findings suggest that, in this model of acute PMN mediated inflammation, a serine protease inhibitor and a metalloprotease inhibitor have similar anti-inflammatory properties, that inflammation is not mediated by proteolysis with generation of chemotactic matrix fragments, and that classic antiproteolysis (complexing of protease to antiprotease) probably does not play a role in suppression of inflammation. The antiproteolytic effects of these agents do not seem to be mediated by protection of endogenous alpha1AT.

Animals↗

PubMed2001

Anti-subnucleosome reactivities in systemic lupus erythematosus (SLE) patients and their first-degree relatives.

Antibodies specific for dsDNA appear to have different genetic origins and pathogenic consequences, compared with histone/dsDNA-specific antibodies, in a recently described murine model. The purpose of this study was to examine if this is also true in human lupus. Sera from 40 SLE families (comprising 40 probands and 153 first-degree relatives), and 45 normal adult controls were assayed for the levels of anti-dsDNA, anti-H1/dsDNA, anti-H2A/H2B/dsDNA, and anti-H3/H4/dsDNA autoantibodies by ELISA. Both the probands and the first-degree relatives exhibited significantly increased levels of antinuclear antibodies (ANA) targeting the different subnucleosomal epitopes. Importantly, probands with anti-dsDNA antibodies had a significantly higher incidence of renal disease compared with those with just anti-H2A/H2B/dsDNA antibodies, in resonance with murine studies. The frequency of anti-dsDNA and anti-H2A/H2B/DNA ANA among the first-degree relatives was 11.8% and 18.3%, respectively. Surprisingly, whereas probands with anti-dsDNA ANA had families with several seropositive members, first-degree relatives of patients with anti-H2A/H2B/DNA ANA (but not anti-dsDNA ANA) were uniformly ANA-free. These findings suggest that anti-dsDNA ANA in lupus may not only have worse disease associations, they may also have very different genetic origins, compared with anti-H2A/H2B/DNA (or anti-nucleosome) ANA.

Adolescent↗

PubMed2001

The role of caspases in methotrexate-induced gastrointestinal toxicity.

BACKGROUND: Enterocolitis is the major toxicity of methotrexate-based cancer chemotherapy, which limits its clinical applications. Methotrexate induces gut mucosal apoptosis in vivo; however, little is known about the molecular mechanism involved. The effectors of apoptosis include the caspase family of proteases, which are selectively activated in a stimulus-specific and tissue-specific fashion. The aims of this study were (1) to establish an in vitro model of methotrexate-induced gut apoptosis and (2) to determine the role of caspases in methotrexate-induced apoptosis in intestinal epithelial cells. METHODS: Rat intestinal epithelial cells (RIE-1) were treated with methotrexate in the absence or presence of ZVAD-fluoromethyl ketone, a general caspase inhibitor. Apoptosis was quantified by means of deoxyribonucleic acid (DNA) fragmentation assays and Hoechst nuclear staining. Caspase activation was measured with the use of fluorogenic substrates. RESULTS: Methotrexate induced apoptosis and decreased cell number in RIE-1 cells. DNA fragmentation was preceded by the sequential activation of caspases 9, 2, and 3, whereas caspases 1 and 8 remained inactive. ZVAD-fluoromethyl ketone inhibited methotrexate-induced caspase activation, DNA fragmentation, and nuclear condensation. CONCLUSIONS: These results indicate that methotrexate activates specific caspases and induces apoptosis in RIE-1 cells. Furthermore, caspases may play an important role in methotrexate-induced apoptosis in RIE-1 cells and may be potential therapeutic targets to attenuate methotrexate-induced enterocolitis.

Amino Acid Chloromethyl Ketones↗

PubMed2001

Disturbed expression of Fas/FasL on CD4(+) and CD8(+)T cells in Behcet's disease, Vogt-Koyanagi-Harada syndrome, and idiopathic anterior uveitis.

AIMS: To evaluate the expression of Fas/FasL antigen on peripheral blood T lymphocytes in patients with Behcet's disease, Vogt-Koyanagi-Harada (VKH) syndrome, and idiopathic anterior uveitis. METHODS: The expression of Fas and FasL on peripheral blood T lymphocytes was determined using flow cytometry in 26 patients with Behcet's disease (BD), 17 patients with VKH syndrome, 25 patients with idiopathic anterior uveitis, and 43 healthy individuals (controls). RESULTS: A higher proportion of CD4(+) T cells expressing Fas was noted in patients with Behcet's disease (25.70 +/- 7.32%), VKH syndrome (19.60 +/- 11.02%), and idiopathic anterior uveitis (20.81+/- 7.40%) compared with controls (14.02 +/- 6.30%). The expression of Fas on CD8(+) cells from patients with Behcet's disease (9.47 +/- 6.97%) and VKH syndrome (6.84+/- 5.5%) was also higher than that seen in controls (3.47+/- 2.75%). There was no difference in FasL expression on T cells between patients and controls except that a lower expression of FasL on CD8(+) T cells was noted in patients with idiopathic anterior uveitis. CONCLUSION: A disturbed expression of Fas and FasL on T cells is present in patients with Behcet's disease, VKH syndrome, and idiopathic anterior uveitis, which may be involved in the perpetuation and recurrence of uveitis.

Adult↗

PubMed2001

[The effects of intrapleural anti-TNFalpha antibody on chemical pleurodesis induced by talc slurry or doxycycline].

OBJECTIVE: To determine whether the intrapleural injection of TNFalpha neutralizing Fab antibody fragment (anti-TNFalpha Fab) would prevent the pleurodesis that occurs after the intrapleural injection of talc or doxycycline. METHODS: In a randomized blinded placebo controlled study, 34 New Zealand white rabbits were given 400 mg/kg talc or 10 mg/kg doxycycline intrapleurally as a sclerosant via a chest tube. Half of the rabbits in each group were also given polyclonal affinity purified anti-TNFalpha Fab 2 000 units or saline as placebo immediately before and 12 hours after the injection of the sclerosants. Chest tube were aspirated at 12 hours intervals until their removal at 4 days. Rabbits were sacrificed at 28 days. The pleural fluid volume, cell counts, LDH and pleurodesis scores were compared among groups. RESULTS: Both talc and doxycycline produced an exudative pleural effusion. The pleural fluid volume and LDH levels were significantly greater in the doxycycline group than talc group. However, the pleural fluid leukocyte counts in talc group were higher than doxycycline group. The administration of anti-TNFalpha Fab had no significant effect on pleural fluid volume, LDH or leukocyte counts in either groups. However, the intrapleural administration of anti-TNFalpha Fab results in a significant decrease in the pleurodesis score for the talc group than doxycycline group (1.8 +/- 0.9 vs 3.2 +/- 0.8). In contrast the pleurodesis score was virtually identical in the doxycycline group with (3.5 +/- 0.5) and without (3.4 +/- 0.7) anti-TNFalpha Fab. CONCLUSION: The intrapleural administration of anti-TNFalpha Fab diminishes the pleurodesis induced by talc but not that which results from doxycycline. These findings suggest that different mechanisms are involed with the two different sclerosants.

Animals↗

PubMed2001

[Values of TNF, IL-8, sICAM-1 and CD11b/CD18 in benign and malignant pleural effusions].

OBJECTIVES: To explore the significance of TNF, IL-8, sICAM-1 and CD11b/CD18 in pleural effusions and/or in peripheral blood in formation of pleural effusions and the possible role in differential diagnosis. METHODS: Levels of TNF, IL-8, sICAM-1 and PMN CD11b/CD18 expression were measured by radioimmunoassay (RIA), enzyme-linked immunosorbent assay (ELISA) and flow cytometry (FCM). 31 patients with tuberculous pleural effusions, 31 malignant pleural effusions and 31 healthy persons as control were studied. RESULTS: The serum levels of TNF, IL-8 and PMN CD11b/CD18 expression in benign and malignant effusions were markedly higher than those in controls (P < 0.01). The levels of TNF, IL-8 and PMN CD11b/CD18 in patients with tuberculous pleural effusions were elevated higher than those with malignant effusions (P < 0.01). The levels of sICAM-1 in pleural effusions were much lower in tuberculosis than malignancy (P < 0.01). TNF levels in pleural effusions were positively correlated to the IL-8 and sICAM-1 levels (r = 0.74 and 0.79, respectively, P < 0.01). TNF levels in serum was positively correlated to the PMN CD11b/CD18 expression (r = 0.61, P < 0.01), but the latter was negatively correlated to sICAM-1 levels of pleural effusions (Y = 1442.31 - 36.85X + 0.25X(2), R(2) = 0.59, F = 19.83, P < 0.01). CONCLUSIONS: The results show that TNF, IL-8, sICAM-1 and CD11b/CD18 may work and affect each other in immunopathological process of tuberculous and malignant pleural effusions. The changes of TNF, IL-8 in pleural effusions and the expressions of PMN CD11b/CD18 are of clinically diagnostic value in distinguishing tuberculous from malignant pleural effusions.

Adult↗

PubMed2001

[Comparison of the diagnostic value of telomerase activity with CEA level in benign and malignant pleural effusions].

OBJECTIVE: To study the diagnostic value of telomerase activity in differentiating malignant from nonmalignant pleural effusions. METHOD: Sixty-five specimens of pleural effusion were examined for telomerase activity and CEA level by PCR-ELISA and EIA, respectively. According to the final diagnosis achieved, the patients were classified into two groups: group I, 35 nonmalignant pleural effusions, group II, 30 malignant pleural effusions diagnosed by either fluid cytology or pleural biopsy. The results of telomerase activity were compared with CEA levels. RESULTS: Two of thirty-five (5.7%) samples of pleural effusions in group I were found to possess weak telomerase activity and 27 of 30 (90%) samples in group II showed positive enzymatic activity. The diagnostic sensitivity is 0.90, specificity is 0.94, and the positive and negative predictive value are 0.93 and 0.92, respectively. The overall accuracy is 0.92. The diagnostic efficiency of CEA as following: sensitivity 0.60, specificity 0.89, positive and negative predictive value are 0.82 and 0.72, respectively, accuracy 0.75. CONCLUSION: The results indicate that the detection of telomerase activity in pleural effusions is more sensitive, more accurate than CEA in differentiating benign from malignant effusions and can be used as an adjunctive measure in the diagnosis of malignant pleural effusions.

Adult↗