SEARCH · PubMed Health

Results for “Expression profiling”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,567 records · Page 87Linked to original sources

PubMed2006

Gene expression profiling of human ovarian tumours.

There is currently a lack of reliable diagnostic and prognostic markers for ovarian cancer. We established gene expression profiles for 120 human ovarian tumours to identify determinants of histologic subtype, grade and degree of malignancy. Unsupervised cluster analysis of the most variable set of expression data resulted in three major tumour groups. One consisted predominantly of benign tumours, one contained mostly malignant tumours, and one was comprised of a mixture of borderline and malignant tumours. Using two supervised approaches, we identified a set of genes that distinguished the benign, borderline and malignant phenotypes. These algorithms were unable to establish profiles for histologic subtype or grade. To validate these findings, the expression of 21 candidate genes selected from these analyses was measured by quantitative RT-PCR using an independent set of tumour samples. Hierarchical clustering of these data resulted in two major groups, one benign and one malignant, with the borderline tumours interspersed between the two groups. These results indicate that borderline ovarian tumours may be classified as either benign or malignant, and that this classifier could be useful for predicting the clinical course of borderline tumours. Immunohistochemical analysis also demonstrated increased expression of CD24 antigen in malignant versus benign tumour tissue. The data that we have generated will contribute to a growing body of expression data that more accurately define the biologic and clinical characteristics of ovarian cancers.

Adenocarcinoma, Clear Cell↗

PubMed2006

Identification of transcripts associated with cell wall metabolism and development in the stem of sugarcane by Affymetrix GeneChip Sugarcane Genome Array expression profiling.

Sugarcane is an important crop in tropical regions of the world, producing a very large biomass and accumulating large amounts of sucrose in the stem. In this study, we present the first report of transcript profiling using the GeneChip Sugarcane Genome Array. We have identified transcripts that are differentially expressed in the sugarcane stem during development by expression profiling using the array and total RNA derived from three disparate stem tissues (meristem, internodes 1-3, 8, and 20) from four replicates of the sugarcane variety Q117 grown in the field. We have identified 119 transcripts that were highly differentially expressed with development and have characterised members of the cellulose synthase (CesA) and cellulose synthase-like (Csl) gene families, which displayed coordinated expression during stem development. In addition, we determined that many other transcripts involved in cell wall metabolism and lignification were also co-expressed with members of the CesA and Csl gene families, offering additional insights into the dynamics of primary and secondary cell wall synthesis in the developing sugarcane stem.

Cell Wall↗

PubMed2005

Cytokine gene expression profiles of bovine dendritic cells after interaction with Mycobacterium avium ssp. paratuberculosis (M.a.p.), Escherichia coli (E. coli) or recombinant M.a.p. heat shock protein 70.

Mycobacterium avium paratuberculosis (M.a.p.) resides and replicates in macrophages. Many of the of immune mechanisms aiding M.a.p. survival in the host's cells are known. However, little is known about interactions of M.a.p. with dendritic cells (DC). As DC are important for the induction of protective immunity against infectious diseases, we investigated the interaction of M.a.p. with these cells. Quantitative real-time PCR (RT-PCR) was used to analyse differential expression of cytokine genes after 6 h and 24 h of incubation by immature DC that phagocytosed either M.a.p. or Escherichia coli (E. coli). We hypothesized that phagocytosis of E. coli would induce pro-inflammatory cytokines due to abundant presence of lipopolysaccharide (LPS) and that the cytokine expression profile induced by phagocytosis of live M.a.p. would differ. In addition we hypothesized that incubation of immature DC with rHsp70, an immunodominant antigen of M.a.p., would induce a similar profile of cytokine gene expression as phagocytosis of intact M.a.p. However, phagocytosis of both E. coli and M.a.p. resulted in a cytokine gene expression pattern representative of a (pro-)inflammatory reaction, dominated by strong induction of IL-12 gene expression, that was higher after 24 h than after 6 h of incubation, although the response to M.a.p. was less vigorous than to E. coli. Incubation with rHsp70 resulted in a more inhibitory type of cytokine gene expression, with delayed IL-12 gene expression and downregulation of the genes for IL-1beta and IL-6 after 24 h of incubation. We conclude that bovine DC produce an immuno-stimulatory, anti-mycobacterial response to infection with M.a.p., while Hsp70 potentially contributes to pathogen virulence by allowing the bacteria to invade the host cell.

Animals↗

PubMed2006

Gene expression profile by inhibiting Raf-1 protein kinase in breast cancer cells.

Raf-1 protein serine-threonine kinase plays an important role in cell growth, proliferation, and cell survival. Previously, we and others have demonstrated that antisense raf oligonucleotide-mediated inhibition of Raf-1 expression leads to tumor growth arrest, radiosensitization and chemosensitization in vivo. Raf-1 inhibition is also associated with apoptotic cell death. In this study, we inhibited Raf-1 using an antisense raf oligonucleotide (AS-raf-ODN) to identify downstream targets of Raf-1 using microarray gene expression analysis. Treatment of MDA-MB-231 breast cancer cells with 250 nM AS-raf-ODN led to significant inhibition of Raf-1 protein (75.2 +/- 9.6%) and c-raf-1 mRNA levels (86.2 +/- 3.3%) as compared to untreated control cells. The lipofectin control or mismatch oligonucleotide had no effect on Raf-1 expression. To determine the changes in gene expression profiles that were due to inhibition of Raf-1, we simultaneously compared the gene expression patterns in AS-raf-ODN treated cells with untreated control cells and cells treated with lipofectin alone or MM-ODN. A total of 17 genes (4 upregulated and 13 down-regulated) including c-raf-1 were identified that were altered after AS-raf-ODN treatment. Functional clustering analysis revealed genes involved in apoptosis (Bcl-XL), cell adhesion (paxillin, plectin, Rho GDIalpha, CCL5), metabolism (GM2A, SLC16A3, PYGB), signal transduction (protein kinase C nu), and transcriptional regulation (HMGA1), and membrane-associated genes (GNAS, SLC16A3). Real-time PCR, Northern analysis and Western analysis confirmed the microarray findings. Our study provides insight into Raf-1 related signaling pathways and a model system to identify potential target genes.

Blotting, Northern↗

PubMed2006

Gene expression profiles of brain dopamine neurons and relevance to neuropsychiatric disease.

Dysfunction of dopamine neurons has been implicated in several neuropsychiatric disorders, including Parkinson's disease, addiction, bipolar disorder and depression. Recent elucidation of gene expression profiles in dopamine neuron subpopulations has shed light on the function of different groups of dopamine neurons in the CNS and on their dysfunction in disease states. In particular, concerted differences in gene expression appear to underlie the unique properties of distinct dopamine neurons. Specifically, dopamine neurons in the substantia nigra (SN), which are prone to degenerate in Parkinson's disease, express high levels of transcripts related to energy metabolism, mitochondria and phosphate signalling pathways. In contrast, ventral tegmental area (VTA) dopamine neurons prominently express genes related to synaptic plasticity and neuropeptides, suggesting intriguing mechanisms for the involvement of VTA dysfunction in addiction and mood disorders. As new functions of dopaminergic neurotransmission become clearer, continued exploration of the transcriptional neuroanatomy of these unique neurons will be vital for producing targeted, selective, and effective therapeutic agents.

Animals↗

PubMed2006

Differential gene expression profiling in aggressive bladder transitional cell carcinoma compared to the adjacent microscopically normal urothelium by microdissection-SMART cDNA PCR-SSH.

Identifying novel and known genes that are differentially expressed in aggressive bladder transitional cell carcinoma (BTCC) has important implications in understanding the biology of bladder tumorigenesis and developing new diagnostic and therapeutic agents. In this study we identified the differential gene expression profiles comparing tumor to the adjacent microscopically normal mucosa by manual microdissection on frozen sections. The RNAs extracted from microdissected tissues were amplified by SMART cDNA PCR technology to generate forward subtractive cDNA library by suppressive subtractive hybridization (SSH). We obtained 376 positive clones, one hundred clones of aggressive BTCC subtracted cDNA library were selected at random and inserts were reamplified by PCR. After differential screening by reverse dot blotting, 73 positive clones, that contend inserts putatively upregulated in aggressive BTCC, were further analysed by DNA sequencing, GenBank and EST database searching. Sequencing results showed that 66 clones stand for 23 known genes and 7 clones for three new EST (Genbank number: DN236875, DN236874 and DN236873). In conclusion, microdissection-SMART cDNA PCR-SSH allowed for an efficient way to identify aggressive BTCC-specific differential expressed genes that may potentially be involved in the carcinogenesis and/or progression of aggressive BTCC. These differentially expressed genes may be of potential utility as therapeutic and diagnostic targets for aggressive BTCC.

Carcinoma, Transitional Cell↗

PubMed2006

Strain-dependent pulmonary gene expression profiles of a cystic fibrosis mouse model.

Cystic fibrosis (CF) lung disease severity is influenced by unknown genetic factors apart from the disease causative gene, cystic fibrosis transmembrane conductance regulator (CFTR). Previous studies have shown the C57BL/6J congenic Cftr(-/-) (B6 CF) mouse to develop a fibrotic lung disease compared with both CF mice of the BALB/c background and wild-type animals. In this report, gene expression profiling with microarrays was used to identify genes differentially expressed in the lungs of B6 and BALB CF mice compared with non-CF littermates. Seven hundred two genes or expressed sequence tags (ESTs) were identified to be differentially expressed between the B6 CF and non-CF control lungs (P < 0.05), and, by Gene Ontology classification, the B6 CF response included the cell proliferation categories of DNA metabolism and mitosis. In the response of BALB mice to nonfunctional Cftr, 943 genes/ESTs were differentially expressed compared with controls. The biological processes of apoptosis and T and B cell proliferation were prominent in the gene list of the BALB CF strain. In support of this strain difference, increased T lymphocyte infiltration was evident in the lungs of BALB CF mice, through immunohistochemical staining, compared with the lungs from both B6 CF and non-CF control mice. Four hundred forty-four genes/ESTs were differentially expressed between B6 CF and BALB CF mice (P < 0.05, fold > 2), including 56 that map to previously identified linkage intervals. These results suggest that the variable severity of CF lung disease in this mouse model is controlled by multiple genetic factors, including those of an immune response.

Animals↗

PubMed2001

Analysis of temporal gene expression profiles: clustering by simulated annealing and determining the optimal number of clusters.

MOTIVATION: Cluster analysis of genome-wide expression data from DNA microarray hybridization studies has proved to be a useful tool for identifying biologically relevant groupings of genes and samples. In the present paper, we focus on several important issues related to clustering algorithms that have not yet been fully studied. RESULTS: We describe a simple and robust algorithm for the clustering of temporal gene expression profiles that is based on the simulated annealing procedure. In general, this algorithm guarantees to eventually find the globally optimal distribution of genes over clusters. We introduce an iterative scheme that serves to evaluate quantitatively the optimal number of clusters for each specific data set. The scheme is based on standard approaches used in regular statistical tests. The basic idea is to organize the search of the optimal number of clusters simultaneously with the optimization of the distribution of genes over clusters. The efficiency of the proposed algorithm has been evaluated by means of a reverse engineering experiment, that is, a situation in which the correct distribution of genes over clusters is known a priori. The employment of this statistically rigorous test has shown that our algorithm places greater than 90% genes into correct clusters. Finally, the algorithm has been tested on real gene expression data (expression changes during yeast cell cycle) for which the fundamental patterns of gene expression and the assignment of genes to clusters are well understood from numerous previous studies.

Algorithms↗

PubMed2005

Differentiation of follicular thyroid adenoma from carcinoma by means of gene expression profiling with adapter-tagged competitive polymerase chain reaction.

OBJECTIVE: Since preoperative differentiation between follicular thyroid adenoma (FTA) and carcinoma (FTC) remains very difficult, the purpose of this study was to identify the genes differentially expressed in FTA and FTC in order to construct a diagnostic system based on such genes for differentiation of FTA and FTC. METHODS: Gene expression profiles of 45 FTAs and 22 FTCs were analyzed by means of adapter-tagged competitive polymerase chain reaction (ATAC-PCR) with 2,516 genes (learning set). The genes differentially expressed in FTAs and FTCs were then used to construct a diagnostic system based on the weighted-voting algorithm. In addition, a validation study of this diagnostic system was conducted using 12 FTAs and 6 FTCs (validation set). RESULTS: The diagnostic system for differentiation of FTA and FTC, constructed with the aid of the learning set samples, was based on 60 genes differentially expressed in FTA and FTC, which included several genes previously identified as overexpressed in FTC (DPP4, KRT19 and IGFBP3) or FTA (trefoil factor 3 and thyroid peroxidase). The leave-one-out cross-validation study showed that the accuracy of this diagnostic system was as high as 90% (sensitivity: 77.3% and specificity: 95.6%), and was confirmed by the validation study (diagnostic accuracy: 83.3%; 95% confidence interval: 62.8-95.4%, sensitivity: 66.7% and specificity: 91.2%). CONCLUSIONS: This diagnostic system using the ATAC-PCR assay is expected to be clinically useful for preoperative differentiation between FTA and FTC since ATAC-PCR can be used for the small amount of RNA obtained from fine needle aspiration biopsy.

Adenoma↗

PubMed2002

Gene expression profiling in chronic myeloid leukemia patients treated with hydroxyurea.

Using array technology that allows the simultaneous detection of gene expression of hundreds of genes, four patients with chronic myeloid leukemia (CML) were investigated at diagnosis and after starting administration of hydroxyurea. To detect the gene expression of peripheral blood mononuclears and granulocytes Human Cancer cDNA Array (CLONTECH) with 588 gene probes was used. Gene expression mononuclear and granulocyte profiles of patients at diagnosis were compared with the control profiles. The significant expression changes observed in most patients seemed to be important. Increased expression of c-jun N-terminal kinase 2 (JNK2), integrin alpha E, MMP-8, MMP-9 was detected in both fractions of most patients. In some samples PCNA, HDGF, MAPK p38, CD59 increased expressions were found. Significant down-regulation of expression in patients was detected in genes CDK4 inhibitor A, PURA, notch1 in mononuclears; STAT2, STAT5, RAR-alpha, MCL-1, junB, caspase 4 in granulocytes; CDK6, GADD153, ERBB-3, cadherin 5 in both fractions. Expression profiles detected in patients at diagnosis did not differ markedly from those after one-week treatment with hydroxyurea. Only in a few genes were significant changes after hydroxyurea administration observed and inter-individual expression differences were rather common.

Adult↗

PubMed2003

Clinically potential subclasses of retinoid synergists revealed by gene expression profiling.

Retinoids have chemopreventive and therapeutic potency in oncology and dermatology, although their application is restricted by many undesirable side effects. For the development of more effective and less toxic retinoids, gene expression analyses using DNA microarrays have the potential to supplement conventional screening methods, which are based on the changes in cell morphology and/or function. In this study, we applied the class prediction algorithm, which was used in the molecular phenotyping of tumors, for the classification of synthetic retinoids (Am80 and Tp80) and retinoid synergists (HX630, TZ335, and PA024) as all-trans retinoic acid-like, 9-cis retinoic acid-like, and control-like classes. By analyzing the effects of all-trans retinoic acid and 9-cis retinoic acid on the gene expressions in a human promyelocytic leukemia cell line, HL60, we successfully selected 50 marker genes whose expression pattern could distinguish these classes. Moreover, the classification revealed the existence of two subclasses among the retinoid synergists used with Am80. Close inspection of the DNA microarray analyses indicated that these two subclasses had different effects on the apoptosis of HL60 cells, and this was confirmed by in vivo experiments. These results indicate that the retinoidal activity of Am80, which has already been used in clinical trials, could be modulated differently by the two classes of retinoid synergists. Thus, these two subclasses of retinoid synergists have the potency to widen the usage of Am80. Our analyses demonstrated that the gene expression profiling could provide important information for developing useful retinoid synergists by compensating conventional screening methods.

Alitretinoin↗

PubMed2004

Gene expression profiling of bovine macrophages in response to Escherichia coli O157:H7 lipopolysaccharide.

The aim of this study was to identify changes in bovine macrophage gene expression in response to treatment with Escherichia coli 0157:H7 lipopolysaccharide (LPS), utilizing a human gene microarray. Bovine cDNA from control and LPS-treated primary macrophages hybridized to greater than 5644 (79.8%) of the non-control gene targets on a commercially available microarray containing greater than 7075 targets (Incyte Genomics, St. Louis, MO). Of these target sequences, 44 were differentially expressed upon exposure to LPS, including 18 genes not previously reported to exist in cattle. These included a pentaxin-related gene, CASP8, TNF-induced genes, interferon-induced genes, and inhibitors of apoptosis. Using the human microarray, cDNA from bovine LPS-treated and control macrophages consistently hybridized to targets known to be expressed constitutively by macrophages, as expected given the predicted cDNA sequence homology. That this human system was accurately estimating levels of bovine transcripts was further verified by real-time quantitative reverse transcriptase polymerase chain reaction (RTQ-PCR) using bovine-specific primers. This first report of bovine-human cross-species expression profiling by microarray hybridization demonstrates the utility of this technique in bovine gene expression and discovery.

Animals↗

PubMed2002

Microarray-based expression profiling of normal and malignant immune cells.

Recent advances in gene microarray technology have facilitated global analyses of gene expression profiles in normal and malignant immune cells. Great strides have been made in our understanding of molecular differences among various types of immune cells, the process of T and B cell activation, and the genomic changes that convert normal cells to malignant ones. Genomic analysis has become a crucial aspect of cancer classification, diagnosis, therapy, and prognosis. This technology has the potential to reveal the comprehensive transcriptional alterations that dictate fundamental biological processes such as signal transduction in response to specific stimuli, cell growth, differentiation, and apoptosis. While reaping the benefits of genomic analyses, it is important to realize its limitations with respect to accuracy of interpretation, reproducibility, and signal detection. It is crucial to optimize signals for individual probe-target pairs and to develop a uniform set of criteria for data analyses. The development of a public-access database of results from individual laboratories will pave the way for identifying discrepancies and advancing scientific breakthroughs.

Gene Expression Profiling↗

PubMed2002

Analysis of gene expression profile in p130(Cas)-deficient fibroblasts.

p130(Cas) (Cas) is a docking protein that becomes tyrosine phosphorylated in v-Src- or v-Crk-transformed cells and in integrin-stimulated cells. Cas -/- fibroblasts show defects in stress fiber formation, cell spreading, cell migration, and transformation by activated Src. To further characterize the role of Cas in signaling, we compared the expression profile in Cas -/- fibroblasts with that in Cas-re-expressing fibroblasts using the microarray methods. In Cas -/- fibroblasts, the expression of heme oxygenase 1 and caveolin-1 was reduced, but the expression of procollagen 1 alpha 1, procollagen 3 alpha 1, procollagen 11 alpha 1, elastin, periostin, TSC-36, and MARCKS was enhanced. The domains in Cas necessary for the change varied among these genes. Activated Src reduced the expression of most of these genes both in Cas -/- and in Cas +/+ fibroblasts. These results suggest the existence of signaling pathways that emanate from Cas to gene expression.

Animals↗

PubMed2004

Microarray expression profiling reveals candidate genes for human uterine receptivity.

The endometrium undergoes cyclic changes in response to circulating ovarian steroid hormones as it prepares for implantation. This dynamic tissue is well suited to microarray expression profiling for elucidation of molecular players participating in the maturation of the endometrium and during the process of implantation. Recent advances in sequencing the human and mouse genomes and the availability of microarray technology and bioinformatic analyses have made elucidating these molecular participants and dialogs a reality. Analysis of the window of implantation, a temporal and spatially unique period in which the endometrium is receptive to embryonic implantation, has revealed numerous processes to be occurring simultaneously or sequentially. These include cell cycle regulation, angiogenesis, immune modulation of implantation, defense mechanisms put into place by antibacterial agents and detoxicants, secretion of unique products, transport of ions and water, growth factor actions, steroid hormone action and metabolism, and production of extracellular matrix proteins, unique cell surface glycoproteins, and a variety of transcription factors, to name a few. Several groups have recently conducted studies with human endometrium, and remarkable similarities exist with mouse. Also, many genes and gene families involved in the unique differentiation process of stromal cell decidualization are conserved. In addition, infertility associated with endometriosis is partly implantation-based, and gene profiling of such tissue during the window of implantation has revealed additional insight into mechanisms underlying infertility in this disorder. Global profiling of genes in the endometrium, decidua, and at the interface between the trophoblast and the decidua, has provided remarkable in sight into endometrial maturation and implantation.

Animals↗

PubMed2001

Expression profiling reveals hepsin overexpression in prostate cancer.

Prostate cancer is the most commonly diagnosed noncutaneous cancer in men. Despite this fact, many of the genetic changes that coincide with prostate cancer progression remain enigmatic. We have addressed this problem by characterizing the expression profiles of several benign and malignant human prostate samples, and we have identified several genes that are differentially expressed between benign and malignant glands. One gene that was overexpressed encodes the serine protease hepsin. We used an independent sample set to confirm that hepsin is overexpressed in prostate tumors, and in situ hybridization demonstrates that hepsin is specifically overexpressed in the carcinoma cells themselves. These facts, together with the molecular properties of hepsin, make it an ideal target for prostate cancer therapy.

Gene Expression Profiling↗

PubMed2005

Gene expression profiling of arthritis using a QTL chip reveals a complex gene regulation of the Cia5 region in mice.

One of the major quantitative trait loci (QTLs) associated with arthritis in crosses between B10.RIII and RIIIS/J mice is the Cia5 on chromosome 3. Early in the congenic mapping process it was clear that the locus was complex, consisting of several subloci with small effects. Therefore, we developed two novel strategies to dissect a QTL: the partial advanced inter-cross (PAI) strategy, with which we recently found the Cia5 region to consist of three loci, Cia5, Cia21 and Cia22, and now we introduce the QTL-chip strategy, where we have combined congenic mapping with a QTL-restricted expression profiling using a novel microarray design. The expression of QTL genes was compared between parental and congenic mice in lymph node, spleen and paw samples in five biological replicates and in dye-swapped experiments at three time points during the induction phase of arthritis. The QTL chip approach revealed 4 genes located in Cia21, differently expressed in lymph nodes, and 14 genes in Cia22, located within two clusters. One cluster contains six genes, differently expressed in spleen, and the second cluster contains eight genes, differently expressed in paws. We conclude the QTL-chip strategy to be valuable in the selection of candidate genes to be prioritized for further investigation.

Animals↗

PubMed2001

Expression profile of human herpesvirus 8 (HHV-8) in pyothorax associated lymphoma and in effusion lymphoma.

AIMS: Pyothorax associated lymphoma (PAL) occurs in a clinical setting of longstanding pyothorax or chronic inflammation of the pleura. Like primary effusion lymphoma, it has an association with Epstein-Barr virus (EBV), and is confined to the pleural cavity, but has differing morphological and phenotypic features. Human herpesvirus 8 (HHV-8) has been consistently reported in primary effusion lymphoma. This study examines the immunophenotype of two European cases of PAL, investigates the presence of HHV-8 and its expression profile, and assesses whether PAL is similar to other effusion lymphomas. METHODS: Material was obtained from two European cases of PAL. Immunocytochemical analysis was performed using antibodies against CD45, CD20, CD79a, CD45RAA, CD3, CD43, CD45RO (UCHL1), CD30, BCL-2, CD68, epithelial membrane antigen (EMA), BCL-6, p53, Ki-67, kappa light chain, lambda light chain, and the EBV antigens latent membrane protein 1 (LMP-1) and EBV encoded nuclear antigen 2 (EBNA-2). The cases were examined for HHV-8 by means of polymerase chain reaction in situ hybridisation (PCR-ISH), solution phase PCR, in situ hybridisation (ISH), and real time quantitative TaqMan PCR to HHV-8 open reading frame 26 (ORF-26) and viral (v) cyclin encoding regions. The expression profile of HHV-8 in PAL and in BC-1 and BC-3 cells was assessed by RNA TaqMan PCR to the HHV-8 genes encoding v-cyclin, v-IL-6, and G protein coupled receptor (GPCR). RESULTS: Both cases expressed CD24, CD20, CD79a, BCL-2, light chain restriction, and high Ki-67 staining. EBV was identified by EBER-ISH in one case. HHV-8 was not identified by solution phase PCR, but was detected by PCR-ISH (sensitivity of 1 viral genome copy/cell) in 35% of the cells and by TaqMan PCR, which showed 50-100 HHV-8 copies/2,000 cell genome equivalents (sensitivity of 1 viral genome in 10(6) contaminating sequences). HHV-8 v-IL-6, v-cyclin, and GPCR encoded transcripts were identified using RNA TaqMan PCR. v-IL-6 was high in PAL and in BC-1 and BC-3 cells. CONCLUSION: The presence of HHV-8 in one of two patients with PAL raises interesting questions in relation to the pathobiology of the condition. Clearly, the results indicate that HHV-8 is not an obligate pathogen, necessary for the effusion phenotype, but might contribute to it by its secretion of specific cytokines.

Aged↗