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PubMed1989

Species-specific interpretive breakpoints for ciprofloxacin disk diffusion susceptibility testing.

When ciprofloxacin was introduced on the Swedish market the recommended interpretive standards for disk diffusion susceptibility testing using a 10 microgram disk were: Sensitive greater than or equal to 24 mm (MIC less than or equal to 1 mg/l) and Resistant less than 18 mm (MIC greater than 4 mg/l), except for enterococci where S greater than or equal to 18 mm and R less than 14 mm were recommended. A quality control study revealed that the accuracy of the routine susceptibility testing of ciprofloxacin was low. 50% of the strains of Staphylococcus aureus and 90% of Streptococcus agalactiae strains were falsely assigned to the intermediate instead of the sensitive category, and the test missed to detect true resistance in Pseudomonas maltophilia. New species-specific breakpoints were determined by the SRA method. Separate breakpoints were required only for the pseudomonas species. Streptococcus faecalis was found to belong mainly to the intermediate group and it is suggested that these strains are not categorized as sensitive. The breakpoints that gave acceptable accuracy in routine susceptibility testing of ciprofloxacin were S greater than or equal to 20 mm, R less than 13 mm for all relevant bacteria except Pseudomonas aeruginosa for which S greater than or equal to 27 mm, R less than 18 mm is proposed, and Pseudomonas maltophilia where S greater than or equal to 30 mm, R less than 23 mm are adequate breakpoints. The 10 microgram disk gave acceptable inhibition zones for all strains with MICs within the clinically interesting MIC range.

Bacteria↗
PubMed1988

The period gene of Drosophila carries species-specific behavioral instructions.

We have analyzed and compared the circadian locomotor activity rhythms of Drosophila melanogaster and D.pseudoobscura. The rhythms of D.pseudoobscura are stronger and the periods shorter than those of D.melanogaster. We have also transformed D.melanogaster flies with a hybrid gene containing the coding region of the D.pseudoobscura period (per) gene. Behavioral assays of flies containing this hybrid gene show that the per protein encoded by the D.pseudoobscura per gene is able to rescue the rhythmic deficiencies of arrhythmic, pero1 D.melanogaster. More important, the rhythms of some of these strains are stronger and the periods shorter than those of D.melanogaster (and those of transformants which carry the equivalent D.melanogaster per gene construct) and hence resemble those of D.pseudoobscura. The results suggest that the primary amino acid sequence of the per gene encodes species-specific behavioral instructions that are detectable when only the per gene is transferred to a different species.

Animals↗
PubMed1995

Immunogenicity of immunoliposomes: reactivity against species-specific IgG and liposomal phospholipids.

Immunoliposomes with surface-linked avidin-biotinylated mouse IgG2a were prepared from dipalmitoylphosphatidylcholine (DPPC), dimyristoylphosphatidylglycerol (DMPG) and biotinylated dipalmitoylphosphatidylethanolamine (DPPE-biotin) in the molar ratio 10:1:0.1 with or without 5 mol% poly(ethylene glycol) dipalmitate (PEG-(C18)2). The ability of IgG2a immunoliposomes to elicit anti-IgG2a antibodies in mice was compared with alum and N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP). IgG2a 5 microgram/mouse) did not elicit an IgG1 antibody response after 4 s.c. injections. Alum-adsorbed IgG2a elicited 2.1 +/- microgram IgG1 antibody/ml serum, whereas MDP elicited 24.3 +/- microgram/ml serum. IgG2a immunoliposomes elicited 12.4 +/- 3.7 microgram IgG1 antibody/ml serum, while immunoliposomes containing lipophilic PEG-(C18)2 elicited 21.4 +/- 5.1 microgram IgG1 antibody/ml serum. Elicited antibodies were specific for IgG2a, with no cross-reactivity with IgG2b. Anti-DPPC or anti-DMPG IgG antibody levels did not change during immunization. Anti-DPPE IgG antibody levels were slightly but significantly elevated during immunization, and there was a significant increase in the level of anti-DPPE-biotin antibodies. These results demonstrate that immunoliposomes prepared with species-specific antibody are immunogenic and induce significant levels of isotypespecific antibody upon repeated injection.

Adjuvants, Immunologic↗
PubMed2006

Species-specific calls activate homologs of Broca's and Wernicke's areas in the macaque.

The origin of brain mechanisms that support human language-whether these originated de novo in humans or evolved from a neural substrate that existed in a common ancestor-remains a controversial issue. Although the answer is not provided by the fossil record, it is possible to make inferences by studying living species of nonhuman primates. Here we identified neural systems associated with perceiving species-specific vocalizations in rhesus macaques using H(2)(15)O positron emission tomography (PET). These vocalizations evoke distinct patterns of brain activity in homologs of the human perisylvian language areas. Rather than resulting from differences in elementary acoustic properties, this activity seems to reflect higher order auditory processing. Although parallel evolution within independent primate species is feasible, this finding suggests the possibility that the last common ancestor of macaques and humans, which lived 25-30 million years ago, possessed key neural mechanisms that were plausible candidates for exaptation during the evolution of language.

Acoustic Stimulation↗
PubMed2000

Fungal endophthalmitis diagnosis by detection of Candida albicans DNA in intraocular fluid by use of a species-specific polymerase chain reaction assay.

Candida endophthalmitis is a serious infection secondary to hematogenous dissemination or direct inoculation of the organisms following trauma or eye surgery. The diagnosis is based on the characteristic findings in the infected eye and on culture of vitreous samples. Unfortunately, the yield of vitreous cultures is limited. The use of a Candida albicans species-specific polymerase chain reaction (PCR) assay in the diagnosis of Candida endophthalmitis is reported herein. Four patients with suspected fungal endophthalmitis underwent vitrectomy for diagnostic and therapeutic purposes. In 2 of the 4, vitreous cultures were negative. However, characteristic PCR products were generated in all 4 patient specimens, enabling the rapid diagnosis of Candida endophthalmitis in all 4. Clinical response was observed in all cases. These results demonstrate the utility of PCR-mediated detection of C. albicans in vitreous samples.

Adult↗
PubMed1976

Differential cytotoxicity of activated lymphocytes on allogeneic and xenogeneic target cells. III. Species specificity of lymphocyte target cell recognition in vitro.

Cytotoxic effector lymphocytes were produced by stimulation of human peripheral blood or mouse spleen lymphocytes with PPD, PHA or PWM in vitro. The specificity of the lymphocyte target cell interaction was studied in vitro. The specificity of the lymphocyte target cell interaction was studied by adsorption of effector cells on various target cell monolayers. The cytotoxic activity of human lymphocytes against 51Cr-labeled human or monkey target cells was reduced by prior incubation on primate monolayers while it was much less affected by incubation on rodent monolayers. Conversely the cytotoxicity of mouse lymphocytes against mouse L cells was strongly reduced by absorption on mouse or rat monolayers but significantly less by that on human monolayers. This suggests that this species-specific cytotoxicity reflects recognition by activated lymphocytes of some common surface structures present only on cells of the species of the effector cell donor, or on cells from phylogenetically closely related species. Lymphocyte-mediated cytotoxicity against xenogeneic target cells was studied after stimulation with PWM. The capacity of human lymphocytes to kill 51Cr-labeled mouse cells was reduced by adsorption on either rodent or primate monolayers. Conversely, prior incubation of mouse lymphocytes on either human or mouse monolayers led to inhibition of 51Cr release from labeled Chang cells. These results suggest that the mitogen-activated effector cells which are cytotoxic for more distantly related xenogeneic target cells have receptors for structures which are common for these cells and for target cells of the species of the lymphocyte donors.

Animals↗
PubMed1987

Species-specific immunodiagnosis of Taenia solium cysticercosis by ELISA and immunoblotting.

A combination of ELISA and immunoblotting was evaluated for immunodiagnosis of human T. solium cysticercosis. The sensitivity of ELISA for diagnosis of European, Latin-American, Asian and South African patients with cysticercosis was 75% for serum and 55% for cerebrospinal fluid specimen. Antigens originating from cysticerci in pigs from Mexico and South Africa were of adequate applicability. A species-specific confirmation of T. solium cysticercosis by immunoblotting (detection of antibody activity to the 26 K and 8 K bands) was achieved in 92% (serum) and 100% (CSF) of samples positive in ELISA. No antibodies from 147 patients with other helminth infections reacted with the 26 K and the 8 K band in immunoblotting, resulting in a specificity of 100%.

Adult↗
PubMed1995

FokI DNA repeats in the genome of Vicia faba: species specificity, structure, redundancy modulation, and nuclear organization.

Tandemly repeated DNA sequences about 60 bp in length, which may be isolated by digestion with FokI restriction endonuclease, were studied by means of molecular and cytological hybridization in Vicia faba and other Vicia species. The results obtained can be summarized as follows: (i) FokI repeats are almost species specific to V. faba, since they hybridize to a minimum extent to genomic DNA of only two out of five related species; (ii) these tandemly repeated elements display variability in structure even within one and the same array, where different repeats may share not more than 71% homology; (iii) their redundancy in the genome of V. faba is remarkably high and varies largely between land races (copy numbers per haploid, 1C, genome range from 21.51 x 10(6) to 5.39 x 10(6)); (iv) FokI repeats are clustered in differing amounts in each subtelocentric pair of the chromosome complement and are missing or present in a nondetectable amount in the submetacentric pair; (vi) chromosome regions that bear these repeats associate closely to varying degrees in interphase nuclei. These results are discussed in relation to possible functional roles that tandemly repeated DNA sequences such as the FokI elements might play.

Base Sequence↗
PubMed2001

Development of a species-specific PCR assay for detection of Leishmania donovani in clinical samples from patients with kala-azar and post-kala-azar dermal leishmaniasis.

We have developed a PCR assay that is capable of amplifying kinetoplast DNA (kDNA) of Leishmania donovani in a species-specific manner among Old World leishmanias. With Indian strains and isolates of L. donovani the assay was sensitive enough to detect kDNA in an amount equivalent to a single parasite or less. The extreme sensitivity of the assay was reflected in its ability to detect parasite DNA from small volumes of peripheral blood of patients with kala-azar (KA) and from skin lesions from patients with post-KA dermal leishmaniasis (PKDL). A total of 107 clinical leishmaniasis samples were analyzed. Of these 102 (95.3%) were positive by PCR. The test provided a diagnosis of KA with 96% sensitivity using patient whole-blood samples instead of bone marrow or spleen aspirates that are obtained by invasive procedures. The assay was also successful in the diagnosis of 45 of 48 PKDL cases (93.8%). Cross-reactions with pathogens prevalent in the area of endemicity, viz., Mycobacterium tuberculosis, Mycobacterium leprae, and Plasmodium spp., could be ruled out. Eighty-one control samples, including dermal scrapings from healthy portions of skin from patients with PKDL were all negative. Two of twenty controls from the area of endemicity were found positive by PCR assay; however, there was a good possibility that these two were asymptomatic carriers since they were serologically positive for KA. Thus, this PCR assay represents a tool for the diagnosis of KA and PKDL in Indian patients in a noninvasive manner, with simultaneous species identification of parasites in clinical samples.

Animals↗
PubMed1990

Species-specific high molecular weight forms of basic fibroblast growth factor.

bFGF was extracted from either mouse, rat and human cell lines or mouse, rat bovine and human brain tissue and partially purified by cation exchange chromatography and heparin-affinity chromatography. When the heparin-affinity purified proteins were probed on Western blots with antisera against either a highly conserved internal bFGF sequence or recombinant 18 kDa bFGF, species-specific forms of bFGF were detected. bFGF proteins from rat and mouse sources were of apparent molecular weight 18,000, 21,500 and 22,000 whereas those from human sources were of 18,000, 22,500 and 24,000. Bovine bFGF proteins were similar to the multiple human bFGFs. The 22.5 kDa and 24 kDa proteins from human cells were also recognized by an antibody specific for the N-terminally extended forms of human bFGF, whereas this antibody failed to detect 18 kDa bFGF. We showed that the differences in molecular weight between human and rat bFGFs are consistent with the predicted ATG (methionine) or alternative CTG (leucine) translational start sites in the 5' upstream sequences of bFGF cDNAs. In addition we show that, irrespective of the species of origin, the larger bFGF proteins may be separated from 18 kDa bFGF by Mono S chromatography.

Amino Acid Sequence↗
PubMed2001

Species-specific organization of CpG island promoters at mammalian homologous genes.

An essential issue derived from the sequencing of the human and other genomes is the identification of gene regulatory elements. Using in vivo footprinting and expression analysis, here we show that mouse and human CpG island promoters at homologous genes have a completely different organization in terms of size and binding of transcription factors. Despite these species-specific differences, a unifying picture emerges from the precise confinement of protein--DNA interactions between the 5' boundary of the CpG islands and the transcription initiation site. This finding allows direct localization of promoters on genomic sequences and reveals a very high rate of variation and evolutionary divergence of mammalian regulatory regions. Our results also show that CpG island promoters associated with tissue-specific genes, such as the human alpha-globin, are bound by ubiquitous factors that allow a constitutive low level of expression in many cell types.

Adenosine↗
PubMed1992

Development of polymerase chain reaction primer sets for diagnosis of Lyme disease and for species-specific identification of Lyme disease isolates by 16S rRNA signature nucleotide analysis.

We have determined and compared partial 16S rRNA sequences from 23 Lyme disease spirochete isolates and aligned these with 8 sequences previously presented. The 16S rRNA signature nucleotide compositions were defined for each isolate and compared with the genomic species signature nucleotide sets previously established. To identify positions truly indicative of species classification which could serve as targets for polymerase chain reaction species-specific identification primers, 16S rRNA-based phylogenetic analyses were conducted. On the basis of the identified signature nucleotides, we designed polymerase chain reaction primer sets which (i) amplify all spirochete species associated with Lyme disease and (ii) differentiate between these species. The primer sets were tested on 38 Borrelia isolates associated with Lyme disease and were found to be sensitive and specific. All Lyme disease isolates tested were amplification positive. These primers allow for the rapid species identification of Lyme disease isolates.

Base Sequence↗
PubMed2005

The neurophysiology of functionally meaningful categories: macaque ventrolateral prefrontal cortex plays a critical role in spontaneous categorization of species-specific vocalizations.

Neurophysiological studies in nonhuman primates have demonstrated that the prefrontal cortex (PFC) plays a critical role in the acquisition of learned categories following training. What is presently unclear is whether this cortical area also plays a role in spontaneous recognition and discrimination of natural categories. Here, we explore this possibility by recording from neurons in the PFC while rhesus listen to species-specific vocalizations that vary in terms of their social function and acoustic morphology. We found that ventral prefrontal cortex (vPFC) activity, on average, did not differentiate between food calls that were associated with the same functional category, despite having different acoustic properties. In contrast, vPFC activity differentiated between food calls associated with different functional classes and specifically, information about the quality and motivational value of the food. These results suggest that the vPFC is involved in the categorization of socially meaningful signals, thereby both extending its previously conceived role in the acquisition of learned categories and showing the significance of using natural categorical distinctions in the study of neural mechanisms.

Action Potentials↗
PubMed1971

Species-specific and interspecific antigenic determinants associated with the structural protein of feline C-type virus.

The group-specific protein of feline leukemia viruses has been isolated by isoelectric focusing. This protein has a molecular weight, calculated from sodium dodecyl sulfate-acrylamide gel electrophoresis, of 25,000 and forms a resolved band in such gels when disrupted virions are analyzed. This protein contains both species-specific antigenic determinants, as well as interspecific cross-reactive determinants, as an integral part of its structure.

Animals↗
PubMed1986

Species-specific non-expression of ribosomal RNA genes in a mammalian hybrid, the mule.

The expression of nucleolus organizer activity in diploid cells was investigated in a model system for mammalian hybrids, the horse-ass cross (mule), by means of sequential Ag-NOR and chromomycin A3/distamycin A-DAPI (CDD) staining in lectin-stimulated peripheral blood lymphocytes (PBL). As a rule we found species-specific non-expression of the horse-derived NOR chromosomes in the mule, whereas the ass-derived NOR chromosomes were active. The results of PBL interphase studies were compatible with the data gained from mitotic metaphase analyses.

Animals↗
PubMed1995

Species-specific expression of cytochrome c oxidase isozymes.

Cytochrome c oxidase was isolated from livers and hearts of sheep, dog and rabbit, and the polypeptide composition was analyzed by two different SDS-PAGE separation systems. The gels were blotted on PVDF-membranes and the N-terminal amino acid sequences of the tissue-specific subunits VIa, VIIa and VIII were determined in a protein sequencer. Except for subunit VIIa from rat, subunits VIa and VIIa from all investigated mammals are tissue-specific expressed in liver and heart. In contrast, subunit VIII is clearly different in liver and heart of bovine, dog and rat, but identical in liver and heart of human (liver-type), sheep, rabbit and also in rainbow trout (heart-type). The data suggest a strong species-specific variation of the regulatory properties of cytochrome c oxidase in different tissues.

Amino Acid Sequence↗
PubMed1995

Coxsackieviral proteins functionally recognize the polioviral cloverleaf structure of the 5'-NTR of a chimeric enterovirus RNA: influence of species-specific host cell factors on virus growth.

The 5'-non-translated region (NTR) of enteroviruses contains secondary structures which do not only serve in the initiation of translation but also in the initiation of plus-strand RNA synthesis by binding of viral and cellular proteins. To investigate a very early step of enteroviral replication by cis- and trans-complementation, 220 nucleotides of the 5'-region of coxsackievirus B3 (CVB3) were exchanged with the corresponding region of poliovirus type 1 (PV1) to yield the chimeric virus CVB3[PV5']. The viability of this chimera demonstrates that the polioviral cloverleaf structure of the 5'-NTR is functional in the replication of a chimeric CVB3 RNA. The HeLa-generated chimera reveals a 4-nucleotide deletion (nt 232-235) within a short direct repeat. Besides clearly reduced growth characteristics in all permissive cell lines, the chimera exhibits a small-plaque phenotype. The host range is changed since the virus grows well in human HeLa cells, but does not replicate in murine YAC-1 and Ltk cells, although these cell lines are permissive for the replication of both parental viruses. Moreover, in simian Vero, COS-1, or FRhK-4 cells the HeLa-generated chimera CVB3[PV5'] exhibits a strict temperature sensitivity at 39 degrees C. After infection of simian cells with high m.o.i. in situ hybridization data reveal that the chimera replicates in single cells at almost normal rates indicating that only a small fraction of HeLa-generated virus is able to multiplicate in simian cell lines. After passaging the virus chimera in Vero cells two further mutations occur at nucleotide positions 185 and 227. Since this genome region is known to interact with viral proteins and several host cell factors during the initiation of replication and translation, interactions of such factors with either viral RNA or viral proteins may be disturbed but still functional at permissive temperatures in HeLa cells and simian cell lines, whereas murine cell lines are not permissive. These experiments suggest that phenomena like host range, tissue tropism and cell-type specificity may be explained as a complex interplay of cellular surface receptors and intracellular host factors. Such intracellular factors could be part of the enteroviral initiation complex during the plus-strand RNA synthesis or during translation initiation and could be expressed in a tissue-, organ- or species-specific way or might be regulated developmentally.

Animals↗
PubMed2004

Species-specific accumulation of interspersed sequences in genus Saccharum.

The genus Saccharum consists of two wild and four cultivated species. Novel interspersed sequences were isolated from cultivated sugar cane S. officinarum. These sequences were accumulated in all four cultivated species and their wild ancestral species S. robustum, but were not detected in the other wild species S. spontaneum and the relative Erianthus arundinaceus. The species-specific accumulation of interspersed sequences would correlate to the domestication of sugar canes.

Agriculture↗