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At least 343 records · Page 19Linked to original sources
PubMed1998

Detection of Mycobacterium avium subsp. paratuberculosis in infected tissues by new species-specific immunohistological procedures.

We have previously described the cloning and sequencing of a gene portion coding for the terminal part of a 34-kDa protein of Mycobacterium avium subsp. paratuberculosis, the etiological agent of Johne's disease (P. Gilot, M. De Kesel, L. Machtelinckx, M. Coene, and C. Cocito, J. Bacteriol. 175:4930-4935, 1993). The recombinant polypeptide (a362) carries species-specific B-cell epitopes which do not cross-react with other mycobacterial pathogens (M. De Kesel, P. Gilot, M.-C. Misonne, M. Coene, and C. Cocito, J. Clin. Microbiol. 31:947-954, 1993). The present work describes the preparation of polyclonal and monoclonal antibodies directed against a362 and the use of these immunoglobulins for histopathological diagnosis of Johne's disease. The new immunohistological procedures herewith detailed proved to be able to identify M. avium subsp. paratuberculosis antigens in the intestinal tissues and lymph nodes of cattle affected by either the paucibacillary or pluribacillary form of the disease. They yielded negative responses not only with healthy animals but also with those affected by tuberculosis (Mycobacterium bovis). Both immunohistological procedures proved to be as sensitive as or more sensitive than Ziehl-Neelsen staining and, in addition, to be endowed with species specificity.

Animals↗
PubMed1990

Preparation of species-specific murine monoclonal antibodies against the yeast phase of Paracoccidioides brasiliensis.

A panel of four murine monoclonal antibodies showing species specificity for the yeast phase of the pathogenic dimorphic fungus Paracoccidioides brasiliensis was produced by using a modification of the standard monoclonal antibody technology. This involved the use of the immunosuppressive drug cyclophosphamide to suppress the immune response of test animals to fungi showing cross-reactivity, i.e., to Histoplasma capsulatum. One monoclonal antibody, P4, which had a high titer by enzyme-linked immunosorbent assay, was shown to recognize a linear antigenic epitope of P. brasiliensis at a molecular size of 70,000 to 75,000 daltons by Western blot (immunoblot) analysis. The potential use of these monoclonal antibodies, which are the first species-specific probes to P. brasiliensis that have been produced, in the field of serodiagnosis is discussed.

Animals↗
PubMed2005

Effects of sedimentation on macroalgae: species-specific responses are related to reproductive traits.

Although increases in sedimentation have been proposed to interfere with benthic communities in many coastal areas worldwide, few experimental studies have investigated the effect of sedimentation on community composition and assessed species-specific responses. In a field experiment on a rocky shore on the Swedish east coast (northern Baltic Proper) we confirmed the hypotheses that ambient sedimentation influences macroalgal abundance and community composition, and that species-specific responses to sedimentation correlate with reproductive strategies. We followed the establishment and development of macroalgal vegetation on artificial substrates at 8-m and 15-m depth for 4.5 years while manipulating the depositional environment by regularly removing accumulated sediment. Sediment removal significantly favoured macroalgal development and vegetation cover. Responses of macroalgal species to the sediment treatments were clearly species-specific; for example, the ephemeral green algae (Cladophora glomerata and Enteromorpha spp.) were highly tolerant to sedimentation while belt-forming perennial brown algae (Fucus vesiculosus and Sphacelaria arctica) were not. Accordingly, multivariate analyses (redundancy analysis) showed that variance in species abundances were significantly correlated to sediment conditions. The effect of sediment removal was higher at 15-m than at 8-m depth and some species' distributions seemed limited in depth by the present sediment load (e.g. F. vesiculosus). Vegetative propagation was common in the study area and many species mainly depended on dispersal by fragmentation. Generally, species with an extended reproductive period, either by long continuous spore release (C. glomerata and Enteromorpha spp.) or vegetative dispersal by fragmentation (e.g. Furcellaria lumbricalis and Polysiphonia fucoides), were most tolerant to sedimentation. This paper demonstrates long-term effects of sediment deposition on the development of a macroalgal community over several growing seasons. The results indicate that variation in sediment loads is an important constraint for species' local distributions and abundances, and affects the composition of sublittoral rocky-shore macroalgal communities.

Ecosystem↗
PubMed1994

The major species specific epitope in prion proteins of ruminants.

The species specific nature of an antigenic determinant previously discovered in the scrapie form of prion protein (PrPD) from cattle, sheep and mice, was further investigated in normal prion protein (PrPC) from these and other species. This was carried out with eight different anti-peptide sera raised in rabbits against various synthetic peptides representing segments of the amino acid (aa) sequence 101-122 of ovine, bovine, murine and hamster PrP. Antipeptide serum against a peptide representing aa 107-122 of ovine PrP showed almost specific reaction and crossreacted in immunoblot with caprine and human PrP only. Antisera to the corresponding bovine sequence stained bovine and porcine PrP and to a minor extent PrP of goat, man, cat, and mink, while antiserum to the murine aa sequence reacted with rodent and monkey PrP only. In contrast, antiserum to the corresponding hamster sequence displayed a broader reactivity pattern, just like the four other anti-peptide sera to various ovine and bovine sequences. Antisera were also tested for reactivity with the pathogenic isoforms of PrP of sheep, cow, hamster and mouse and showed generally similar reactivity patterns as by using PrPC. In conclusion, the region close to the actual or putative proteinase K cleavage sites of PrP seems to exhibit high structural variability among mammalian species.

Amino Acid Sequence↗
PubMedDate not supplied

[Development of species specific acoustic sensitivity in hole-nester fledgelings].

A study was made of acoustic sensibility of hole nestlings to species-specific signals of adult birds. It has been established that the final formation of sensibility to such signals is not completed in the embrional period of development, but continues, at least during the first half of life in the nest. In the embrional period, the formation of sensibility is concluded only within the spectrum of the "alimentary" signal complex, providing for adequate alimentary behaviour of the nestlings immediately after hatching. In the early postembrional period, the formation of acoustic sensibility in the spectrum of other species-specific signals (alarm signals) is completed in parallel with the organization of behavioral reactions controlled by these stimuli.

Animals↗
PubMed2002

Analysis of the 16S-23S rDNA intergenic spacers (IGSs) of marine vibrios for species-specific signature DNA sequences.

Vibrios are widespread in the marine environment and a few pathogenic species are known to be commonly associated with outbreaks of diarrheal diseases in humans due to the consumption of raw or improperly cooked seafood. However, there are also many Vibrio species which are potentially pathogenic to vertebrate and invertebrate aquatic animals, and of which little is known. In an attempt to develop rapid PCR detection methods for these latter class of vibrios, we have examined the 16S-23S intergenic spacers (IGSs) of 10 lesser-known Vibrio species and successfully developed species-specific primers for eight of them--Vibrio costicola, V. diazotrophicus, V. fluvialis, V. nigripulchritudo, V. proteolyticus, V. salmonicida, V. splendidus and V. tubiashii. The IGS amplicons were amplified using primers complementary to conserved regions of the 16S and 23S rRNA genes, and cloned into plasmid vectors and sequenced. Analysis of the IGS sequences showed that 37 ribosomal RNA (rrn) operons representing seven different IGS types have been cloned from the 10 vibrios. The three IGS types--IGS(0), IGS(IA) and IGS(Glu)--were the most prevalent forms detected. Multiple alignment of representative sequences of these three IGS types from different Vibrio species revealed several domains of high sequence variability, which were used to design species-specific primers for PCR. The specificity of the primers were evaluated using total DNA prepared from different Vibrio species and bacterial genera. The results showed that the PCR method can be used to reliably detect eight of the 10 Vibrio species in marine waters in this study.

Base Sequence↗
PubMed1978

Perception of sounds used in species-specific communication: the auditory cortex and beyond.

The auditory cortex, located in the superior temporal gyrus, has been studied in squirrel monkeys with respect to its role in detecting species-specific vocalizations. Single neurons tested with selected vocalizations from the species' repertoire have been grouped into seven functional categories. Each category reflects a different level of processing with regard to vocalizations and artificial sounds. It is argued that, while the auditory cortex has the capability to detect and distinguish species-specific vocalizations, the interpretation of their biological significance likely takes place elsewhere.

Animal Communication↗
PubMedDate not supplied

Influence of various types of species-specific acoustic signals on the heart rate of mammals.

It has been demonstrated in the experiments on rodents and artiodactyles that significant changes in the heart rate (HR) in response to the presentation to animals of species-specific acoustic signals are manifested only under the conditions of a deficit of pragmatic information. The HR is determined in many respects by the type of signal, by the ecological particularities, and the physiological state of the animal perceiving the signal. In colonial and herd mammals, inhabitants of open spaces, susliks and reindeer, marked changes in HR are observed only under conditions which exclude the acquisition of visual information regarding changes in the social milieu. The development of an active avoidance conditioned reflex in arctic susliks in response to one of the types of species-specific alarm signals, a series of cries (with automatization of the skill) leads to a decrease in the depth and probability of the cardiological reaction both to the conditional stimulus as well as to another type of species-specific alarm signals, whistling. It was demonstrated that the biological dominant of maternal care in white rats, according to HR data, selectively influences the degree of emotiogenicity of the acoustic signal of discomfort in the young.

Acoustic Stimulation↗
PubMed1991

Cloning and characterization of a species-specific repetitive DNA sequence from Loa loa.

A genomic DNA library of Loa loa was constructed in lambda gt11 using EcoRI-digested DNA from microfilariae isolated from two West African patients. Screening with labeled L. loa DNA yielded several potential repetitive DNA clones. An MboI fragment of one of these, LL3M9, was identified and characterized. Sequence analysis of LL3M9 revealed an 839-bp fragment with an unusual 356-bp region containing 37 copies of the hexamer CTTAGG, many of which are arranged in repeated motifs of 12, 27 and 63 bp. This region shares many of the characteristics of eukaryotic satellite DNA. A synthetic oligonucleotide corresponding to the 27-bp repeated motif, LL3M9REP, was found to be both sensitive and species-specific by dot hybridization. Species specificity of LL3M9REP was confirmed by amplification of the repetitive region using genomic DNA as a template in the polymerase chain reaction.

Animals↗
PubMed1999

Highly sensitive and species-specific assay for quantification of human transgene expression levels.

During the past few years great efforts have been made to construct and to test human factor VIII (hFVIII) and IX (hFIX) vectors suitable for haemophilia gene therapy in vivo. However, little is known about the molecular mechanisms of persistence and shut-off of transgene expression in the target organs after gene transfer using recombinant adenoviral vectors. To evaluate low transgene mRNA levels in different tissues, especially at long times after the gene transfer, the common northern blot method is often not sensitive enough. For this reason we developed a new, highly sensitive and species-specific method for hFIX mRNA quantification and employed it in mice treated with an adenoviral vector (Ad5CMVFIX) expressing human FIX. In addition to its very high sensitivity (lowest detection level=1 fg RNA), the method was shown to be strictly species-specific, since hFIX mRNA signals were never detected in untreated mice. In a long-term study of 18 vector-treated mice we compared the human FIX:Ag levels in the mouse plasma, the human FIX mRNA levels and human FIX vector DNA concentrations in the mouse liver. We found that a slow but continuous decrease of hFIX:Ag levels in mouse plasma was associated with a corresponding decrease of hFIX mRNA levels in the liver. However, the Ad5CMVFIX vector DNA levels did not decrease to a comparable degree, suggesting that the decrease of human FIX:Ag levels in mouse plasma is, to a significant extent, also caused by CMV promotor shut-off and only to a minor degree by loss of vector DNA.

Adenoviridae↗
PubMed1994

Rapid detection and identification of Candida albicans and Torulopsis (Candida) glabrata in clinical specimens by species-specific nested PCR amplification of a cytochrome P-450 lanosterol-alpha-demethylase (L1A1) gene fragment.

PCR of a Candida albicans cytochrome P-450 lanosterol-alpha-demethylase (P450-L1A1) gene segment is a rapid and sensitive method of detection in clinical specimens. This enzyme is a target for azole antifungal action. In order to directly detect and identify the clinically most important species of Candida, we cloned and sequenced 1.3-kbp fragments of the cytochrome P450-L1A1 genes from Torulopsis (Candida) glabrata and from Candida krusei. These segments were compared with the published sequences from C. albicans and Candida tropicalis. Amplimers for gene sequences highly conserved throughout the fungal kingdom were first used; positive PCR results were obtained for C. albicans, T. glabrata, C. krusei, Candida parapsilosis, C. tropicalis, Cryptococcus neoformans, and Trichosporon beigelii DNA extracts. Primers were then selected for a highly variable region of the gene, allowing the species-specific detection from purified DNA of C. albicans, T. glabrata, C. krusei, and C. tropicalis. The assay sensitivity as tested for C. albicans in seeded clinical specimens such as blood, peritoneal fluid, or urine was 10 to 20 cells per 0.1 ml. Compared with results obtained by culture, the sensitivity, specificity, and efficiency of the species-specific nested PCR tested with 80 clinical specimens were 71, 95, and 83% for C. albicans and 100, 97, and 98% for T. glabrata, respectively.

Amino Acid Sequence↗
PubMed1992

A PCR-based method of identifying species-specific repeated DNAs.

A PCR-based method is described to facilitate the identification of DNA fragments that are highly repeated and species-specific. The precision of the technique was demonstrated by cloning a fragment that occurred in a high number of copies in the plant species Medicago granadensis but in a low number of copies in 17 other Medicago species and Melilotus officinalis. This method should greatly accelerate the isolation and cloning of short and long interspersed nuclear elements with species-specific distributions. Such clones should prove useful in studies of phylogenetic relationships in the identification of interspecific hybrids, as in situ chromosome markers and other applications.

Base Sequence↗
PubMed1999

Species specificity of cytokeratin polypeptide expression in the submandibular gland.

Using nine monospecific and seven polyspecific monoclonal antibodies (MoAbs) against cytokeratin (CK), we immunohistochemically studied the species specificity of CK localization in human, rat, mouse, hamster and guinea pig submandibular glands (SMGs). All species showed different staining patterns with various degrees of intensity. The pattern of immunostaining was broadly classified into three groups. Group I showed positive reactivity to the rodent salivary gland, but not to human SMGs (6B10 and 34betaE12). Group 2 showed the reverse staining pattern (M20, A53-B/A2 and Ks19.1). Group 3, for which almost all species were positive, showed interspecific diversity in the staining pattern (CY-90, K8.12, K8.13, C-11 and KH-1). Species specificity of CK should always be taken into consideration when immunohistochemically examining CK expression during development or during carcinogenesis in rodents.

Animals↗
PubMed1998

Species-specific immunostaining of embryonic corneal nerves: techniques for inactivating endogenous peroxidases and demonstration of lateral diffusion of antibodies in the plane of the corneal stroma.

Species-specific and species-common monoclonal antibodies (MAbs) to nerve-specific cell surface epitopes were used to compare pre-treatment techniques for nerve staining. Endogenous peroxidases were inactivated in four ways: (1) 0.3% hydrogen peroxide (H2O2); (2) 1% periodic acid (PA) (pH 1.85-1.95); (3) sodium meta-periodate (10-40 mM, pH 4.5); or (4) HCl (pH 1.80). Staining of chick and quail corneal nerves and dorsal root ganglia (DRG) nerves with the MAbs was species-specific. Staining of chick and quail corneal nerves was unaffected by pre-treatment with 0.3% H2O2, but was eliminated by pre-treatment with 1% PA. Chick and quail DRG nerve staining tolerated 0.3% H2O2, and at least one epitope also tolerated 1% PA. Corneal nerves of both chick and quail displayed concentration-dependent sensitivity to pre-treatment with sodium meta-periodate; DRG nerves were not sensitive to such pre-treatment. Corneal nerves tolerated pre-treatment with HCI (pH 1.80), whereas DRG nerves did not. These findings indicate sensitivity of corneal nerve epitopes to oxidation, in contrast with sensitivity of DRG nerve epitopes to low pH. Results also indicate that tissue trimming regulated whole-mount staining of corneal nerves, suggesting that antibodies cannot diffuse across corneal basement membranes, even after detergent extraction. However, antibodies are able to diffuse laterally into the stroma from any cut edge.

Animals↗
PubMedDate not supplied

Marked species specificity of guinea pig luteinizing hormone: validation of a bioassay.

The Guinea pig is a potentially interesting alternative small animal model for the study of the neuroendocrine regulation of reproduction. However, appropriate gonadotropin assays are not widely available for this species. The aim of the present study was to validate a bioassay procedure for guinea pig luteinizing hormone (LH). The well-established interstitial cell-testosterone in vitro bioassays with the use of dispersed mouse or rat Leydig cells, successfully applied for measurement of LH from a variety of mammalian species, were found to be unsuitable for assay of guinea pig LH because of a marked species specificity of guinea pig LH. An alternative bioassay procedure was established with the use of dispersed guinea pig Leydig cells. This assay has been shown to allow for the assessment of serum LH response to exogenous gonadotropin-releasing hormone and of the expected spontaneous pulsatile pattern of basal LH secretion, with an apparent mean serum LH pulse interval of 31.4 minutes and 51.9 minutes, in long-term castrated and sham operated male guinea pigs, respectively. This bioassay can be a useful tool for more intensive exploration of guinea pig reproductive physiology.

Animals↗
PubMed1986

Stage and species specificity of antigens encoded by two geographic strains of Schistosoma mansoni mRNA.

Proteins translated in vitro from Schistosoma mansoni adult worm mRNA were assessed for their antigenic specificities compared to different stages, strains and species of the parasite. RNA was extracted from both Puerto Rican and Brazilian parasites and directed the synthesis of high molecular weight proteins. Preabsorption of immune human serum with schistosomula was used to determine whether the in vitro translated proteins contained antigens shared between the adult and this immature stage. Three antigens (Mr 36,000, 29,000, 18,000) were observed to be present in both stages. When adult worm mRNA from 2 different geographic strains of S. mansoni (Puerto Rican and Brazilian) were compared, certain antigenic differences were found in their in vitro translation products (proteins at Mr 78,000, 26,000, 24,000, 22,000, 15,500), suggesting that different antigenic pools may exist in nature. The species specificity of the in vitro proteins was assessed using individual sera from humans whose species of schistosome infection and egg counts were known. Immunoprecipitation with these sera demonstrated that a large number of immunologically cross-reactive proteins were shared between S. mansoni and Schistosoma haematobium but not Schistosoma japonicum. Antigens or antigen complexes at Mr 47,000 and 37,000 were detected only in the immunoprecipitations using anti-S. mansoni sera, whereas an antigen of Mr 39,000 was precipitated only by anti-S. haematobium sera. The recognition of any 1 antigen or group of antigens, however, did not distinguish between intensities of infection.

Animals↗
PubMed1990

[Isolation and primary characteristics of the common species-specific outer membrane protein of Rickettsia prowazekii].

Common species-specific protein is isolated for the first time in the chromatographically pure state from the outer membrane of Rickettsia prowazekii, and its amino acid composition is determined. As revealed by chromatofocusing technique, the protein possesses pI 4.18 +/- 0.03. Three basic ninhydrin-positive compounds, differing from usual amino acids, were discovered in the protein hydrolyzate. Data suggesting the subunit structure of the isolated protein are presented.

Amino Acids↗