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PubMed1986

Immunohistologic identification of phenotypic antigens associated with Hodgkin and Reed-Sternberg cells. A paraffin section study.

A combination of two monoclonal antibodies, designated LN-1 and LN-2, were used in an attempt to identify the corresponding antigens in Hodgkin and Reed-Sternberg cells. The LN-1 antibody has been shown in previous studies in our laboratories to identify follicular center cells, whereas LN-2 marks certain B-cell subpopulations as well as interfollicular histiocytes. Utilizing the peroxidase-antiperoxidase (PAP) technique, paraffin-embedded sections were examined representing 39 cases of various histologic subgroups of Hodgkin's lymphoma following immunostaining with LN-1, LN-2, and the antibody to S-100. Of these 39 cases, the LN-2 antibody was found to consistently mark the majority of Hodgkin and Reed-Sternberg cells. LN-1 was found to identify Hodgkin and Reed-Sternberg cells in a smaller number of cases. In no instance were Hodgkin or Reed-Sternberg cells found to mark for the S-100 protein. The use of LN-1 and LN-2 antibodies facilitated the identification of Hodgkin and Reed-Sternberg cells and produced additional information regarding the phenotypic nature of these cells.

Antibodies, Monoclonal↗
PubMed2005

Development of a real-time fluorescence resonance energy transfer PCR to identify the main pathogenic Campylobacter spp.

A simple real-time fluorescence resonance energy transfer (FRET) PCR, targeting the gyrA gene outside the quinolone resistance-determining region, was developed to identify Campylobacter jejuni and Campylobacter coli. These species were distinguished easily, as the corresponding melting points showed a difference of 15 degrees C. A second assay using the same biprobe and PCR conditions, but different PCR primers, was also developed to identify the less frequently encountered Campylobacter fetus. These assays were applied to 807 Campylobacter isolates from clinical specimens. Compared to phenotypic identification tests, the FRET assay yielded the same results for all except three of the isolates. Analysis by standard PCR and 16S rDNA sequencing demonstrated that two of these isolates were hippurate-negative C. jejuni strains, resulting in an erroneous phenotypic identification, while the third was an isolate of C. coli that contained a gyrA gene typical of C. jejuni, resulting in misidentification by the FRET assay. The FRET assay identified more isolates than standard PCR, which failed to yield amplification products with c. 10% of isolates. It was concluded that the FRET assays were rapid, reliable, reproducible and relatively cost-efficient, as they require only one biprobe and can be performed directly on boiled isolates.

Amino Acid Sequence↗
PubMed2004

Genome-wide transposon mutagenesis of Borrelia burgdorferi for identification of phenotypic mutants.

The spirochete Borrelia burgdorferi is the causative agent of Lyme disease, the leading vector-borne illness in the United States. Many of the genetic factors affecting spirochete morphology and physiology are unknown due to the limited genetic tools available and the large number of open reading frames with unknown functions. By adapting a mariner transposon to function in B. burgdorferi, we have developed a random mutagenesis system that tags the mutated locus for rapid identification. Transposition occurs at saturating levels in B. burgdorferi and appears to be random, targeting both linear and circular replicons. By combining the transposon system with a screen for factors affecting growth rate, mutations were readily identified in genes putatively involved in cell division and chemotaxis and a hypothetical open reading frame involved in outer membrane integrity. The successful adaptation of a mariner transposon to function in B. burgdorferi should aid in identifying virulence factors and novel gene products related to spirochete physiology.

Animals↗
PubMed2003

Early diagnosis of Exophiala CAPD peritonitis by 18S ribosomal RNA gene sequencing and its clinical significance.

Phenotypic identification of fungi in clinical microbiology laboratories is often difficult and late, especially for slow growing and rarely encountered fungi. We describe the application of 18S ribosomal RNA (rRNA) gene sequencing in the early diagnosis of a case of Exophiala peritonitis. A yeast-like fungus was isolated from the dialysate fluid of a 66-year-old man undergoing continuous ambulatory peritoneal dialysis. It grew slowly after 12 days of incubation to yield mature cultures to permit recognition of microscopic features resembling those of Exophiala, a dematiacerous mold. 18S rRNA gene sequencing provided results 12 days earlier than phenotypic identification and revealed 15 base difference (0.9%) between the isolate and Exophiala sp. strain GHP 1205 (GenBank Accession no. AJ232954), indicating that the isolate most closely resembles a strain of Exophiala species. The patient responded to 4 weeks of intravenous amphotericin B therapy. Early identification of the fungus was important for the choice of anti-fungal regimen. As opportunistic fungal infections in immunocompromised patients are globally emerging problems, the development of molecular techniques for fungal identification is crucial for early diagnosis and appropriate treatment.

Aged↗
PubMed2003

Phenotypic characterisation of cellular infiltrates in endomyocardial biopsies of heart transplant recipients with diagnosed steroid resistant cellular rejection.

OBJECTIVES: Aim of this study was to find features characteristic for steroid resistant cellular rejection (SRR) of the transplanted heart, using phenotypic identification of cells creating infiltrates in endomyocardial biopsies (EMBs) obtained before and after high dose steroids treatment. METHODS: 146 heart transplant recipients, treated with cyclosporine-A, azathioprine and prednisone, were taken under consideration. EMB results > or = 3A (ISHLT) were considered significant rejection, requiring treatment with 1 g i.v. methylprednizolone for 3 days followed by oral prednisone. SRR was diagnosed in case of increased grade of rejection in control EMB, lack of improvement in 2 consecutive EMBs or increasing hemodynamic compromise. SRR was found in 15 pts. (study group). Control group consisted of remaining 131 pts. Paraffin-embedded blocks containing EMB samples from 9 pts. from study group and randomly chosen 14 pts. from control group were used (2 EMBs per pt.). Significant rejection was present in the first EMB, the second EMB was performed 7 days after beginning of the treatment. In the study group, first 2 EMBs creating a sequence of SRR were analysed. Following antigens were identified: CD45RO (T-cells), CD8 (cytotoxic T-cells), CD20 (B-cells), and CD95 (marker of apoptosis). DR expression and macrophages presence were also quantified. RESULTS: CD45RO was predominant phenotype before and after treatment in both groups. Higher quantity of CD20 cells were observed in study group, however its number increased after treatment in control group. CDB-cells and macrophages were present in low amounts, that did not react to treatment. CD95 positive cells were present only in 3 EMBs. None of above differences was statistically significant. DR expression staining showed no difference either in biopsies taken before steroid treatment or after completing of high dose steroid therapy. CONCLUSION: Phenotype identification of cells infiltrating myocardium of the transplanted heart was not sufficient to predict or characterise steroid resistant rejection.

Antigens, CD20↗
PubMed2004

Phenotype matters: identification of light-responsive cells in the mouse suprachiasmatic nucleus.

The suprachiasmatic nucleus (SCN) of the hypothalamus is the neural locus of the circadian clock. To explore the organization of the SCN, two strains of transgenic mice, each bearing a jellyfish green fluorescent protein (GFP) reporter, were used. In one, GFP was driven by the promoter region of the mouse Period1 gene (mPer1) (Per1::GFP mouse), whereas in the other, GFP was inserted in the promoter region of calbindin-D(28K)-bacterial artificial chromosome (CalB::GFP mouse). In the latter mouse, GFP-containing SCN cells are immunopositive for gastrin-releasing peptide. In both mouse lines, light-induced Per1 mRNA and Fos are localized to the SCN subregion containing gastrin-releasing peptide. Double-label immunohistochemistry reveals that most gastrin-releasing peptide cells (approximately 70%) contain Fos after a brief light pulse. To determine the properties of SCN cells in this light-responsive region, we examined the expression of rhythmic Period genes and proteins. Gastrin-releasing peptide-containing cells do not express detectable rhythms in these key components of the molecular circadian clock. The results support the view that the mammalian SCN is composed of functionally distinct cell groups, of which some are light induced and others are rhythmic with respect to clock gene expression. Furthermore, the findings suggest that gastrin-releasing peptide is a potential mediator of intercellular communication between light-induced and oscillator cells within the SCN.

Animals↗
PubMed2005

Identification and phenotypic characterization of a subpopulation of T84 human colon cancer cells, after selection on activated endothelial cells.

The extravasation of metastatic cells is regulated by molecular events involving the initial adhesion of tumor cells to the endothelium and subsequently the migration of the cells in the host connective tissue. The differences in metastatic ability could be attributed to properties intrinsic of the various primary tumor types. Thus, the clonal selection of neoplastic cells during cancer progression results in cells better equipped for survival and formation of colonies in secondary sites. A cell line (T84SF) exhibiting an altered phenotypic appearance was selected from a colon cancer cell line (T84) by repetitive plating on TNFalpha-activated human endothelial cells and subsequent selection for adherent cells. Cell growth, motility, chemoinvasive abilities, tyrosine phosphorylation signaling, and the metastasis formation in nude mice of the two cell lines was compared. T84SF cells displayed in vitro an higher proliferation rate and a more invasive behavior compared to the parental cells while formed in vivo a greater number of metastatic colonies in nude mice. As concerns the signaling underlying the phenotypes of the selected cells, we examined the general tyrosine phosphorylation levels in both cell lines. Our results indicate that T84SF have an increased basal tyrosine phosphorylation of several proteins among which src kinase was identified. Treatment of cells with a specific inhibitor of src activity caused a greater in vitro inhibition of proliferation and invasive properties of T84 parental cells with respect to T84SF cells and diminished metastasis formation in vivo. Altogether, these data provide evidences that this new cell line may be valuable for identifying molecular mechanisms involved in the metastatic progression of colon cancer.

Animals↗
PubMed2005

Identification and phenotype characterization of two CYP3A haplotypes causing different enzymatic capacity in fetal livers.

BACKGROUND: The fetal liver cytochrome P450 (CYP) 3A enzymes metabolize potentially toxic and teratogenic substrates and drugs in addition to endogenous hormones and differentiation factors. CYP3A7 is the most abundant CYP in the human liver during fetal stages and the first months of postnatal age and shows a large interindividual variability of unknown molecular basis. METHODS: A new variant gene (CUpsilonP3A7*2), which carries a mutation in exon 11 of CUpsilonP3A7 causing a T409R substitution, was identified by direct sequencing. Genotype analysis was performed by use of polymerase chain reaction followed by restriction enzyme analysis. CYP3A7.2 activity was assessed in heterologous expression systems and human fetal liver microsomes. RESULTS: The frequency of CUpsilonP3A7*2 was 8%, 17%, 28%, and 62% in white, Saudi Arabian, Chinese, and Tanzanian individuals, respectively. By use of human HEK293 cells, no significant differences in expression between CYP3A7.1 and CYP3A7.2 were found and fetal livers homozygous for CUpsilonP3A7*2 had similar or higher CYP3A7 protein contents than CUpsilonP3A7*1 livers. Kinetic studies showed that CYP3A7.2 was a functional enzyme with a significantly higher catalytic constant (kcat) as compared with CYP3A7.1 (P < .05). Interestingly, fetal livers that expressed CYP3A7.2 also expressed CYP3A5 protein, and we found a linkage disequilibrium between the CUpsilonP3A7*2 and CUpsilonP3A5*1 alleles that was subject to interethnic differences. Determination of the alprazolam 1-hydroxylation rate revealed that CYP3A5 plays a significant role in the metabolism of CYP3A substrates in the fetal liver. CONCLUSION: We have identified 2 different CYP3A phenotypes in the fetal liver--one that is the result of a CUpsilonP3A7*1/CUpsilonP3A5*3 haplotype causing CYP3A7.1 but no CYP3A5 expression and another with higher detoxification capacity, inherent in the CUpsilonP3A7*2/CUpsilonP3A5*1 haplotype, where CYP3A5 and a more active form of CYP3A7 are expressed.

Aryl Hydrocarbon Hydroxylases↗
PubMed2004

Identification and phenotypic characterization of the cell-division protein CdpA.

Analysis of the automated computer annotation of the early draft phase genome of Lactobacillus acidophilus NCFM revealed the previously discovered S-layer gene slpA and an additional partial ORF with weak similarities to S-layer proteins. The entire gene was sequenced to reveal a 1799-bp gene coding for 599 amino acids with a calculated molecular mass of 64.8 kDa. No transcription or translation signals could be determined in close proximity to the 5'-region. However, a strong putative terminator with a free energy of -16.84 kcal/mol was identified directly downstream of the gene. A PSI-Blast analysis showed similarities to members of S-layer proteins, cell-wall associated proteinases and hexosyl-transferases. Calculation of an unrooted phylogenetic tree with other examples of S-layer proteins and proteinases placed the deduced protein separately from both groups. A derivative of L. acidophilus NCFM was constructed by targeted integration into the gene. SDS-PAGE analysis of non-covalently linked proteins of the cell wall of the mutant, compared to the wild type, revealed the loss of a cell-surface protein. Phenotypic analyses of the mutant revealed significant changes in cell morphology, altered responses to various environmental stresses, and lowered cell adhesion. Based on the in silico and functional analyses, we ascertained that this protein plays a role in cell-wall processing during the growth and cell-cell separation and designated the gene as cell-division protein, cdpA.

Bacterial Adhesion↗
PubMed1997

Identification and phenotypic analysis of two glyoxalase II encoding genes from Saccharomyces cerevisiae, GLO2 and GLO4, and intracellular localization of the corresponding proteins.

We have isolated and characterized two genes coding for the glyoxalase II enzyme from Saccharomyces cerevisiae. The coding region of the GLO2 gene corresponds to a protein with 274 amino acids and a molecular mass of 31,306 daltons. The open reading frame of the GLO4 gene could be translated into a protein with 285 amino acids and a molecular mass of 32,325 daltons. The amino acid sequences of the deduced proteins are 59.1% identical and show high similarities to the sequence of the human glyoxalase II. When grown on either glucose or glycerol as a carbon source, a glo2 glo4 double deletion strain contains no glyoxalase II activity at all and shows no obvious phenotype during vegetative growth. However, this strain showed a similar high sensitivity against exogenous methylglyoxal as compared with a glyoxalase I-deficient strain. Whereas the GLO2 gene is expressed on both glucose and glycerol, the GLO4 gene is only active on glycerol. The active Glo2p protein is localized in the cytoplasm and the active Glo4p in the mitochondrial matrix. Heterologous expression of the full-length GLO2 coding region in Escherichia coli resulted in an active protein. However, to get an active Glo4p protein in E. coli, the putative mitochondrial transit peptide at the N-terminal end had to be removed by shortening the 5' end of the GLO4 open reading frame.

Amino Acid Sequence↗
PubMed2002

Enumeration, phenotyping, and identification of activation events in conjugates between T cells and antigen-presenting cells by flow cytometry.

Microscopic analysis of T cell-antigen-presenting cell (T cell:APC) interactions at the single cell level has been a powerful, but tedious and subjective, technique. In this paper, we describe a rapid and quantitative method to identify T cell:APC conjugates using succinimidyl ester dyes, which irreversibly label free amine groups on the cell surface. The labeled cell conjugates and subsequent activation events are detected by flow cytometry.

Animals↗
PubMed2004

Identification and phenotyping of leukocytes in bovine bronchoalveolar lavage fluid.

A method is proposed to identify leukocyte subpopulations in bovine bronchoalveolar lavage fluid by dual-laser flow cytometry. The technique uses several parameters, i.e., exclusion of highly autofluorescent alveolar macrophages and inclusion of leukocytes on the basis of labeling by specific antibodies and light scatter characteristics.

Animals↗
PubMed1995

Application of capillary electrophoresis in the identification of phenotypes containing the beta-lactoglobulin C variant.

A method for the separation of the beta-LG variants A, B, and C was developed using free zone capillary electrophoresis. A separation buffer consisting of 50 mM 2-(N-morpholino)ethane sulfonic acid (pH 8.0) and polyoxyethylene (20)-sorbitan monolaurate was used for the separation. Milk samples from 424 Jersey cows were phenotyped using this method, and the gene frequencies for beta-LG A, B, and C were .41, .53, and .06, respectively. These frequencies were different from those found in studies of Jersey populations in other countries, where the beta-LG B allele had a significantly higher frequency, and the beta-LG A allele a significantly lower frequency, than those of this present study. The frequency of the beta-LG C allele was intermediate to those of other studies. The concentration of beta-LG in the milk was different among the beta-LG phenotypes and was, from greatest to least: AA, AB, AC, BB, and BC.

Animals↗
PubMed2005

Identification of phenotypic neural stem cells in a pediatric astroblastoma.

OBJECT: The goal of this study was to illustrate the findings of a significant subpopulation of cells within a pediatric astroblastoma that have the specific cell surface phenotype found on known human neural stem cells. METHODS: Cells with a cell surface marker profile characteristic of human neural stem cells were isolated using fluorescence-activated cell sorting from a mostly nonmitotic astroblastoma removed from the brain of an 11-year-old girl. An unusually high proportion (24%) of the cells were CD133 positive and CD24, CD34, and CD45 negative (CD133(+)CD24(-)CD34(-)CD45(-) cells), the phenotypic antigenic pattern associated with neural stem cells; very few CD133-positive cells were not also CD24, CD34, and CD45 negative. Some cells (12%) were CD34 positive, indicating the presence within the tumor of hematopoietic stem cells. Cells formed cytospheres that resembled neurospheres when seeded into stem cell media and coexpressed beta-tubulin and glial fibrillary acidic protein (GFAP) but did not express the oligodendrocyte marker O4. Cell proliferation was demonstrated by incorporation of bromodeoxyuridine. The cells lost their capacity for self-renewal in vitro after four to six passages, although they continued to coexpress beta-tubulin and GFAP. The cells did not differentiate into neurons or astrocytes when placed in differentiation medium. CONCLUSIONS: Although this astroblastoma contained a high proportion of phenotypic neural stemlike cells, the cells had limited proliferative capacity and multipotency. Their role in astroblastoma formation and growth is unknown.

Antigens, CD↗
PubMed2003

[Identification of phenotype and Interferon-alpha-producing capability of circulating type II dendritic cells and its clinical implication in HBV-infected patients].

OBJECTIVE: To investigate the number, phenotype, and interferon-alpha (INF-alpha) of type II dendritic cells (DC2) in persons with hepatitis B and evaluate the role of DC2 subset in the immunopathogenesis of chronic HBV infection. METHODS: Peripheral blood was extracted from 103 hepatitis B (HB) virus-infected persons, including 11 cases of HB virus (HBV)-infected persons, 11 cases of acute HB, 81 cases of chronic HB, and 11 cases of asymptomatic HBV infection, and 25 healthy blood donors used as controls. Flow cytometry was used to calculate the number and the phenotype of circulating DC2. Ultraviolet-inactivated herpes simplex virus (HSV)-1 was added into the suspension of peripheral blood mononuclear cells (PBMCs) and then co-cultured for 24 hours to stimulate the production of INF-alpha by DC2 that was examined by ELISA assay. RESULTS: The number of DC2 in patients with chronic HB was 3.3 +/- 1.0 10(6)/L, significantly lower than that in the healthy controls (7.2 +/- 2.4 10(6)/L, P < 0.01). However, the number of DC2 was not significantly different between any other groups. The proportion of GS2 to PBMCs in the patients with chronic HB was 1.12 +/- 1.13 approximately 0.22 +/- 0.10, all significantly lower than that in the healthy controls (0.32% +/- 0.13%, P < 0.01). However, the proportion of GS2 to PBMCs was not significantly different between any other groups. The decrease of number of DC2 and that of proportion of DC2 to PBMCs in patients with chronic HB were related with the progress of disease. The INF-alpha concentration in the suspensions of PBMCs of different groups without stimulation by HSV-1 were low and there was no significant difference in INF-alpha concentration between different groups. The INF-alpha concentration in the suspension of PBMCs of healthy controls was 789 +/- 82 pg/ml, significantly higher than those of the patients with acute HB (161 +/- 36 pg/ml) and the patients with chronic HB (183 +/- 113 pg/ml, 147 +/- 39 pg/ml, and 156 +/- 39 pg/ml, all P < 0.05). However, there was no significant difference between the patient groups (all P > 0.05). CONCLUSION: The number and INF-alpha producing function of DC2, and the numbers of NK cells and CD8+ T cells in peripheral blood of patients with chronic HB decrease significantly, which results the deficiency of HBV-specific immune response.

Adolescent↗
PubMed1983

The human serum paraoxonase polymorphism: identification of phenotypes by their response to salts.

A method for identifying two human serum paraoxonase phenotypes in vitro has been developed based upon the effect of NaCl upon paraoxonase activity. In a sample population of 336 individuals from the United States, 53.9% of the samples had serum paraoxonase that was highly stimulated (60%-257% above the control activity) by 1 M NaCl (salt-responsive), whereas the activity of the remaining samples was not salt-responsive (-23%-35%). The degree of stimulation was consistent and reproducible in frozen samples collected from an individual over a two-year period. Pedigree studies with 37 families indicate that the salt-responsive characteristic is inherited as a simple autosomal, Mendelian trait. Although the salt-responsive individuals on the average had a higher level of activity when assayed without added salt (basal activity) than did the non-salt-responsive individuals, there was considerable overlap in the basal paraoxonase activities. The quantitative polymorphism in serum paraoxonase activity observed in other laboratories is associated with a qualitative difference, quite possibly due to two distinct isozymic forms of the enzyme. A new designation for these alleles is proposed, and some preliminary studies on the molecular basis of the polymorphism are reported.

Alleles↗
PubMed1983

Identification of phenotypically distinct subpopulations of cytotoxic T lymphocytes.

Two distinct subpopulations of cytotoxic T lymphocytes (CTL) were identified on the basis of their expression of a marker recognized by a monoclonal antibody H9/25. Conventional bulk mixed lymphocyte reactions (MLR) against either major histocompatibility antigens or minor histocompatibility antigens yield cytotoxic T cells which carry the H9/25 marker (H9/25+). Removal of H9/25+ spleen cells before MLR culture did not prevent the generation of CTL. However, the CTL had the phenotype H9/25-. These results imply that two distinct subpopulations of CTL exist, H9/25+ and H9/25-. Under normal conditions the H9/25+ CTL subpopulation dominates. Removal of H9/25+ spleen cells from the responder spleen cell population before MLR stimulation allows the expression of the otherwise silent H9/25- subpopulation of CTL. The data suggest that H9/25+ spleen cells regulate the expression of CTL subpopulations in bulk MLR cultures.

Animals↗
PubMed1994

Deletions spanning the neurofibromatosis 1 gene: identification and phenotype of five patients.

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder characterized by marked variation in clinical severity. To investigate the contribution to variability by genes either contiguous to or contained within the NF1 gene, we screened six NF1 patients with mild facial dysmorphology, mental retardation, and/or learning disabilities, for DNA rearrangement of the NF1 region. Five of the six patients had NF1 gene deletions on the basis of quantitative densitometry, locus hemizygosity, and analysis of somatic cell hybrid lines. Analyses of hybrid lines carrying each of the patient's chromosomes 17, with 15 regional DNA markers, demonstrated that each of the five patients carried a deletion > 700 kb in size. Minimally, each of the deletions involved the entire 350-kb NF1 gene; the three genes--EVI2A, EVI2B, and OMG--that are contained within an NF1 intron; and considerable flanking DNA. For four of the patients, the deletions mapped to the same interval; the deletion in the fifth patient was larger, extending farther in both directions. The remaining NF1 allele presumably produced functional neurofibromin; no gene rearrangements were detected, and RNA-PCR demonstrated that it was transcribed. These data provide compelling evidence that the NF1 disorder results from haploid insufficiency of neurofibromin. Of the three documented de novo deletion cases, two involved the paternal NF1 allele and one the maternal allele. The parental origin of the single remaining expressed NF1 allele had no dramatic effect on patient phenotype. The deletion patients exhibited a variable number of physical anomalies that were not correlated with the extent of their deletion. All five patients with deletions were remarkable for exhibiting a large number of neurofibromas for their age, suggesting that deletion of an unknown gene in the NF1 region may affect tumor initiation or development.

Adolescent↗