Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SPECIES SPECIFICITY”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 199 records · Page 11Linked to original sources
PubMed1998

An immuno-biological test of species specificity in a low-molecular organic extract (<10,000 D).

A pharmacological formulation derived from bovine blood was studied for species-specific substances, the problem being the low-molecular weight of its components. A detection of the species specificity for bovines was possible exclusively by the use of monovalent bovine-specific blood group sera. All other sera showed cross-reactions. Inhibition tests and blood-group-specific bovine test sera enabled us to identify the species specificity of bovines in the drug concentrate at dilutions up to 1/1,000 which are used as the basis for the production of the medication. The requirement of the German authorities (BGA) to examine the specificity of the identity in the medication can therefore be met by this immunobiological method.

Animals↗
PubMed1988

The binding of mouse hybridoma and human IgE antibodies to the major fecal allergen, Der p I, of Dermatophagoides pteronyssinus. Relative binding site location and species specificity studied by solid-phase inhibition assays with radiolabeled antigen.

The relative binding site location and species specificity of 19 mouse hybridoma antibodies, produced in four laboratories, to Dermatophagoides pteronyssinus major fecal allergen, Der p I, was studied by using immobilized mAb and inhibitions of radiolabeled Ag binding. Four mAb groups were defined, within which 4, 6, 8, and 5 mAb, respectively, cross-inhibited each other. Five mAb were members of both group 2 and 3, demonstrating a considerable overlap of epitopes between the corresponding antibody-binding regions. The degree of mAb species specificity, as assessed by inhibition with cold Der p I and Ag Der m I and Der f I from the related species, Dermatophagoides microceras and Dermatophagoides farinae, was highly variable even for mAb binding to the same region on the Ag. Five cases of cross-reactivity between Der p I and Der m I and one case of cross-reactivity between Der p I and Der f I were found. The N-terminal 30 amino acids of the three species showed 7 substitutions between Der p I and Der m I/Der f I and 2 between Der f I and Der p I/Der m I. Single mAb inhibited up to 65% of labeled Der p I binding to immobilized human IgE from allergic patients' sera and up to 24% of labeled Der p I binding to immobilized rabbit antibodies. The spectrum of species specificities in human IgE sera, as assessed by inhibitions with cold Ag, was similar to that of the mAb. No evidence for the presence of strictly sequential epitopes, reactive with either mAb or human IgE was found, as judged from the weak inhibitory activity of acid-denatured Der p I.

Adult↗
PubMed1994

Species-specific identification of Sarcocystis and Toxoplasma by PCR amplification of small subunit ribosomal RNA gene fragments.

The small subunit (SSU) ribosomal RNA (rRNA) genes of four cyst-forming coccidia (Sarcocystis tenella, Sarcocystis arieticanis, Sarcocystis gigantea, Toxoplasma gondii) infecting sheep were analysed for unique target sequences which could be used as priming sites for species-specific polymerase chain reactions (PCR). A total of 11 putatively species-specific oligonucleotides were tested in combination with universal oligonucleotides designed for conserved regions of the SSU rRNA genes of eukaryotes. For each parasite species two of these oligonucleotide pairs were found to be ideal primers for species-specific amplification of SSU rRNA gene fragments. The specificity of the PCR assays was optimised by testing different PCR parameters (annealing temperature, magnesium ion concentration, number of amplification cycles) with genomic DNA preparations derived from S. tenella, S. arieticanis, S. gigantea, T. gondii and sheep. The new PCR assays are a powerful tool for species-specific differentiation of the three ovine Sarcocystis spp. and T. gondii.

Animals↗
PubMed2006

Total bacterial and species-specific 16S rDNA micro-array quantification of complex samples.

AIMS: We describe a novel DNA-micro-array-based method that targets 16S rDNA to quantify changes in both the total bacterial DNA and the species-specific DNA composition. METHODS AND RESULTS: Quantifications were achieved by combining competitive PCR for quantifying total bacterial DNA with quantification of species-specific DNA composition based on signature 16S rDNA sequences. We constructed 11 different probes, which were evaluated on 21 different strains, in addition to complex samples. The signals obtained with sequence-specific labelling of the probes corresponded well with what should be expected based on 16S rDNA phylogenetic reconstruction. The quantification of species-specific DNA composition showed that the micro-array approach could be used to accurately determine differential growth of bacteria in mixed samples. We analysed samples containing mixtures of Lactococcus lactis and different species of propionibacteria during a 2-week incubation period. Lactococcus lactis grew fast, reaching a maximum after 12 h, Propionibacterium acidipropionici and Propionibacterium freudenreichii reached a maximum after 48 h, whereas Propionibacterium jensenii showed a slow increase during the whole growth period. The 16S rDNA total bacterial DNA quantification was compared with real-time PCR, absorbance measurements (ABS600) and colony forming units (CFU). CONCLUSION: The accuracy of the array approach was in the same range or better than the alternative techniques. The potential of the 16S rDNA micro-array method was further demonstrated using a liquid cheese model. SIGNIFICANCE AND IMPACT OF THE STUDY: This is to our knowledge the first time quantification of the total bacterial DNA and the species-specific DNA compositions of mixed populations have been achieved in the same assay.

Cheese↗
PubMed1992

Maternal serum reactivity to species-specific antigens in sheep-goat interspecific pregnancy.

Three models were used to test the hypothesis that interspecific pregnancy failure between the sheep and goat is due to a species-specific, maternal antibody response. Interspecific pregnancies were established in ewes and does, sheep in equilibrium goat chimeric conceptuses produced by injection of ovine blastocysts were transferred to ovine recipients, and ovine and caprine pregnancies were established in interspecific chimeras. Complement-mediated lymphocytotoxic and hemolytic assays were used to monitor onset and titer of antibodies. Sera from 3 of 8 injection-chimera recipients reacted with all caprine peripheral blood lymphocytes (PBL) and red blood cells (RBC) tested (n = 18). Sera from 3 of 6 ewes and 7 of 7 does also were pancytotoxic to PBL of the other species (n greater than or equal to 20). Absorptions with xenogeneic RBC generally removed the reactivity. The data were consistent with responses to species-specific, monomorphic antigens expressed on PBL and RBC, and probably trophoblast. The response preceded or coincided with interspecific pregnancy failure in does, but not in ewes. Accordingly, no xenoreactivity was observed in chimera sera but caprine pregnancies were resorbed (n = 16) and ovine pregnancies developed to term (n = 11). The data did not support the hypothesis that failure of caprine pregnancy in ewes or chimeras is due to a species-specific, maternal antibody response. In contrast, a maternal, cytotoxic antibody response to species-specific antigen(s) may contribute to failure of hybrid or ovine pregnancy in does.

Animals↗
PubMed1984

Identification of a species-specific antigen in Legionella pneumophila by a monoclonal antibody.

A species-specific antigen in Legionella pneumophila was identified by a monoclonal antibody in enzyme-linked immunosorbent and immunofluorescence assays of serogroups 1 through 8. The species-specific antigen was heat stable, and the molecular weight of the major band was 29,000 by immunoblot analysis. In direct immunofluorescence assays, the antigen was cryptic or only partly exposed on the surface of the cells but was effectively exposed by treating the cells with detergent and EDTA. The monoclonal antibody was utilized in direct immunofluorescence assays to specifically identify multiple cultures of L. pneumophila serogroups.

Animals↗
PubMed1991

Species-specific patterns of DNA bending and sequence.

Nucleotide sequences in the GenEMBL database were analyzed using strategies designed to reveal species-specific patterns of DNA bending and DNA sequence. The results uncovered striking species-dependent patterns of bending with more variations among individual organisms than between prokaryotes and eukaryotes. The frequency of bent sites in sequences from different bacteria was related to genomic A + T content and this relationship was confirmed by electrophoretic analysis of genomic DNA. However, base composition was not an accurate predictor for DNA bending in eukaryotes. Sequences from C. elegans exhibited the highest frequency of bent sites in the database and the RNA polymerase II locus from the nematode was the most bent gene in GenEMBL. Bent DNA extended throughout most introns and gene flanking segments from C.elegans while exon regions lacked A-tract bending characteristics. Independent evidence for the strong bending character of this genome was provided by electrophoretic studies which revealed that a large number of the fragments from C.elegans DNA exhibited anomalous gel mobilities when compared to genomic fragments from over 20 other organisms. The prevalence of bent sites in this genome enabled us to detect selectively C.elegans sequences in a computer search of the database using as probes C.elegans introns, bending elements, and a 20 nucleotide consensus sequence for bent DNA. This approach was also used to provide additional examples of species-specific sequence patterns in eukaryotes where it was shown that (A) greater than or equal to 10 and (A.T) greater than or equal to 5 tracts are prevalent throughout the untranslated DNA of D.discodium and P.falciparum, respectively. These results provide new insight into the organization of eukaryotic DNA because they show that species-specific patterns of simple sequences are found in introns and in other untranslated regions of the genome.

Algorithms↗
PubMed1981

Species specificity of guinea pig and human lymphotoxin colony inhibitory activity.

The species specificity of lymphotoxin colony inhibitory activity was measured by in vitro colony growth of neoplastic and nonneoplastic cells in the presence of lymphotoxin from the same or from a xenogeneic species. Growth of guinea pig, rat, and mouse neoplastically transformed cells was inhibited by guinea pig lymphotoxin. Colony formation of benzo(a)pyrene transformed 104C1 guinea pig cells was inhibited 45% with lymphotoxin at 42 units/ml medium; nontransformed 104 and 118 guinea pigs cell were not inhibited. Alpha L929, a spontaneously transformed mouse cell, was completely inhibited. Dimethylbenz(a)anthracene (DMBA) 3T3-D and R4-2 mouse transformed cells were inhibited 40 and 100%, respectively, but parental nontransformed 3T3 cells were not inhibited. DMBA transformed R-2 and R-6 rat cells were inhibited 20 and 40%, respectively, but secondary nontransformed fetal rat cells were unaffected. In contrast, normal human xeroderma pigmentosum, Lesch-Nyhan and 1220 fibroblast cells were inhibited 50-60%. No inhibition of HeLa or RPMI 2650 human tumor cells occurred. HeLa and RPMI 2650 cells, however, were inhibited 30 and 60%, respectively, by human lymphotoxin, but normal human and tumorigenic guinea pig cells were unaffected. Thus, guinea pig and human lymphotoxin exhibit species specific and differential cytotoxicity mechanisms for normal and tumor cells.

Animals↗
PubMed1997

Species-specific tRNA recognition in relation to tRNA synthetase contact residues.

In spite of variations in the sequences of tRNAs, the genetic code (anticodon trinucleotides) is conserved in evolution. However, non-anticodon nucleotides which are species specific are known to prevent a given tRNA from functioning in all organisms. Conversely, species-specific tRNA contact residues in synthetases should also prevent cross-species acylation in a predictable way. To address this question, we investigated the relatively small tyrosine tRNA synthetase where contacts of Escherichia coli tRNA(Tyr) with the alpha2 dimeric protein have been localized by others to four specific sequence clusters on the three-dimensional structure of the Bacillus stearothermophilus enzyme. We used specific functional tests with a previously not-sequenced and not-characterized Mycobacterium tuberculosis enzyme and showed that it demonstrates species-specific aminoacylation in vivo and in vitro. The specificity observed fits exactly with the presence of the clusters characteristic of those established as important for recognition of E. coli tRNA. Conversely, we noted that a recent analysis of the tyrosine enzyme from the eukaryote pathogen Pneumocystis carinii showed just the opposite species specificity of tRNA recognition. According to our alignments, the sequences of the clusters diverge substantially from those seen with the M. tuberculosis, B. stearothermophilus and other enzymes. Thus, the presence or absence of species-specific residues in tRNA synthetases correlates in both directions with cross-species aminoacylation phenotypes, without reference to the associated tRNA sequences. We suggest that this kind of analysis can identify those synthetase-tRNA covariations which are needed to preserve the genetic code. These co-variations might be exploited to develop novel antibiotics against pathogens such as M. tuberculosis and P. carinii.

Acylation↗
PubMed1994

Different species-specific chromosome translocations in Triticum timopheevii and T. turgidum support the diphyletic origin of polyploid wheats.

Triticum timopheevii ssp. timopheevii and T. timopheevii ssp. araraticum were analysed by sequential N-banding and genomic in situ hybridization. Three chromosomes, 6At, 1G and 4G, were involved in At-G intergenomic translocations in all six lines analysed. These chromosomes may be derived from a cyclic translocation that is species-specific to T. timopheevii. In contrast, Triticum turgidum has a species-specific cyclic translocation involving chromosomes 4A, 5A and 7B. The discovery of different species-specific chromosome translocations supports the diphyletic hypothesis of the evolution of tetraploid wheats. The results from genomic blocking analysis also revealed that the chromosomes of Aegilops speltoides are closer to the G genome than the B genome chromosomes. The possible role of species-specific translocations in the evolution of wheat is discussed.

Chromosome Banding↗
PubMed1988

Difference in species specificity of TSH receptor antibodies in Graves' disease and Hashimoto's thyroiditis.

UNLABELLED: TSH receptor antibodies have been detected in the sera of patients with Graves' disease (GD) and Hashimoto's thyroiditis (HT). Since non-human thyroid tissue fractions or cells are used in the majority of assays, the species specificity of TSH receptor antibodies in GD or HT could be important. The species specificity was evaluated by means of an immunoprecipitation assay (IPA) using Triton X-100 solubilized TSH receptors prepared from human, porcine and rat thyroid as well as guinea pig fat cells (GPFC). In each assay the majority (4 or 5) of the 6 patients with GD were IPA-positive. In contrast, 9 out of 11 patients (82%) with HT had a positive human and rat IPA, while only 3 out of 11 (27% p less than 0.05) sera were positive in the porcine and GPFC assays. CONCLUSIONS: no species specificity of TSH receptor antibodies was detected for patients with GD; a selective species specificity for human and rat TSH receptors was found for HT sera. This suggests that TSH receptor antibodies in HT either recognize different determinants on the receptor than the antibodies in GD or are of lower affinity. Furthermore, the use of porcine thyroid tissue or GPFC may lead to an underestimation of the presence and level of TSH receptor antibodies in patients with HT.

Animals↗
PubMed1989

Demonstration of species-specific antigens of Gnathostoma spinigerum, a preliminary attempt.

An attempt was made to demonstrate the presence of species-specific antigens for Gnathostoma spinigerum advanced third-stage larvae (GsAL3) in a rabbit receiving weekly immunization with GsAL3 for seven weeks. The homologous and heterologous antibodies against GsAL3 and G. doloresi adult worm (Gd) antigens were initially detected by immunoelectrophoresis (IEP) and ELISA after the second immunization, and their levels were gradually increased with the number of immunizations. Though cross-reactivity between GsAL3 and Gd were shown with both tests, species-specific antibodies for the homologous antigens were demonstrated. After cross-absorption of rabbit hyperimmune serum was collected after the seventh immunization, seven 'putative' species-specific precipitin bands of GsAL3 were identified. The ELISA values of the rabbit hyperimmune serum showed 50% inhibition after absorption with 0.7 micrograms/ml of homologous GsAL3 antigens as opposed to 1.0 micrograms/ml of the heterologous Gd antigens.

Animals↗
PubMed1988

Species specificity in cell-substrate interactions in medusae.

A new system is described for the study of ECM-tissue interactions, using the ECM (called mesogloea) of various cnidarians and isolated striated muscle and endodermal tissue of jellyfish. The mesogloea consists mainly of water and collagen. It is present in all cnidarians and can be isolated without enzyme treatment. It can be used as a substrate to which cells and tissues adhere and on which they spread and migrate. Tissues of striated muscle and endoderm adhere and spread not only on mesogloea from regions they normally cover, but also from other regions of the animal. However, adhesion and spreading are highly species-specific. Species-specific adhesion is found throughout the whole mass of mesogloea even at regions where cells do not occur naturally. The cell adhesion factor can be extracted from the mesogloea so that the mesogloea no longer shows any cell adhesion properties. The extract consists mainly of a cysteine-containing collagen.

Animals↗
PubMed1984

Species-specific second antibodies reduce spurious staining in immunocytochemistry.

Spurious staining related to the second (linking) antibodies was observed in immunocytochemical specimens processed with an unlabeled antibody method. Some of this staining was suspected to result from species cross-reactivity of the second antibodies with endogenous immunoglobulin Gs in the tissue. Therefore, species-specific second antibodies were obtained, and the staining patterns of tissue processed with such antibodies were compared with those of tissue processed with standard (nonspecies-specific) second antibodies. In these studies, a monoclonal antibody to choline acetyltransferase (ChAT) was utilized as the primary antibody, and a similarly prepared monoclonal antibody that did not react with ChAT served as a control antibody. Spurious staining that included staining of discrete tissue and cellular components as well as amorphous background staining was present in both control and experimental tissue processed with standard second antibodies. Such staining was virtually eliminated in tissue processed with species-specific second antibodies. In specimens from the central nervous system, for example, species-specific second antibodies greatly reduced dark staining within the area postrema, in the pia-arachnoid membranes, and around blood vessels as well as the staining of small dot-like structures within some large neurons. In addition, the general level of background staining was reduced in both adult and developing tissues, thus permitting clearer visualization of many positively stained structures. In peripheral tissues such as skeletal muscle, spurious staining of connective tissue elements was eliminated, allowing the observation of previously occluded ChAT-positive structures such as nerve fibers and motor end-plates. Thus, species-specific second antibodies appear to be very useful for immunocytochemistry, particularly when the primary antibody and the tissue to be studied are from closely related species.

Animals↗
PubMed1998

Species-specificity and sensitivity of a PCR-based assay for Perkinsus marinus in the eastern oyster, Crassostrea virginica: a comparison with the fluid thioglycollate assay.

We examined the species-specificity and sensitivity of a polymerase chain reaction (PCR)-based assay for Perkinsus marinus and compared its overall performance with the fluid thioglycollate medium (FTM) assay on oyster (Crassostrea virginica) hemolymph, mantle, and rectum samples. Our results indicated that the PCR-based methodology is species-specific because Perkinsus olseni, Perkinsus atlanticus, and Perkinsus spp. DNAs were not amplified with the PCR primers developed for P. marinus diagnosis. The sensitivity of the PCR method, as assessed through spike/recovery experiments, was established by the detection of as few as 1 cell of P. marinus in 30 mg of oyster tissue. Tissue samples from naturally infected oysters analyzed both by the FTM and PCR assay suggested that the latter was more sensitive for the diagnosis of P. marinus. Positive results for P. marinus infection ranged from 70% to 83% by FTM and from 92% to 100% by PCR, depending on the tissue examined. Therefore, species-specificity and sensitivity of the NTS-based PCR assay validate its use as a tool for assessment of P. marinus in mollusks.

Animals↗
PubMed1999

A single base substitution in the variable pocket of yeast tRNA(Arg) eliminates species-specific aminoacylation.

Early biochemical data showed that aminoacyl-tRNA synthetases often displayed species-specific recognition of tRNA. We compared the ability of purified Saccharomyces cerevisiae and Escherichia coli arginyl-tRNA synthetases to aminoacylate native and transcribed yeast tRNA(Arg) as well as E. coli tRNA(Arg). The kinetic data revealed that yeast ArgRS could charge E. coli tRNA(Arg), but at a lower efficiency than it charged either the transcribed or native yeast tRNA(Arg). E. coli ArgRS can acylate only its cognate E. coli tRNA. Strikingly, a single base change from C to A at position 20 in yeast tRNA(3)(Arg) altered the species specificity. The transcript of yeast tRNA(3)(Arg)CA20 mutant was aminoacylated by E. coli ArgRS with a 10(6) increase in k(cat)/K(m) over that for aminoacylation of yeast tRNA(3)(Arg) transcript. This indicates that A20 is not only an important identity of E. coli tRNA(Arg), but is also the key to altering species-specific aminoacylation of yeast tRNA(Arg).

Amino Acyl-tRNA Synthetases↗
PubMed1998

A species-specific monoclonal antibody to Cynodon dactylon.

BACKGROUND: It is usually difficult to differentiate between the pollens of different grass species on the basis of their appearance under a microscope, as they often appear similar. Such distinctions are important when interpreting the clinical relevance of pollens in air samples as individuals can differ in their allergic responses to different grass species. As this allergenic distinction occurs at the level of presence and differences of epitopes on the allergens associated with different species, it could be anticipated that species-specific monoclonal antibodies could provide such distinctions between pollens. METHOD: Monoclonal antibodies raised against Cynodon dactylon were screened and characterised in ELISA assays and blotting, using a range of grass pollen extracts, to identify clones which were species specific. RESULTS: The most specific monoclonal raised to C. dactylon did not react at a level of greater than 1.2% to extracts of 10 other grass pollens in a direct ELISA assay and showed no detectable cross-reactivity in a particle blotting assay. CONCLUSION: It has been possible to produce a monoclonal antibody that is functionally species specific to C. dactylon.

Animals↗
PubMed2000

Species-specific monoclonal antibodies for rapid identification of Bartonella quintana.

Seven species-specific monoclonal antibodies (MAbs) to Bartonella quintana were produced and characterized. The MAbs were of the immunoglobulin G class and reacted only with 13 B. quintana strains in indirect microimmunofluorescence and Western immunoblotting assays. They did not react with eight other Bartonella spp., including Bartonella henselae, the most closely related species, and a selected MAb did also not react with nine other strains of gram-negative bacteria. The MAbs reacted mainly with a 34-kDa protein epitope of B. quintana which was shown to be species specific by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Four of five body lice experimentally infected with B. quintana were found to be positive for the organism in microimmunofluorescence assays with one MAb. These MAbs may provide a specific, simple, rapid, and low-cost tool for the identification of B. quintana and the diagnosis of infections due to the microorganism.

Animals↗