Biomedical subjects

S Scherer

Publications and source records attributed to S Scherer.

At least 19 recordsLinked to original sources

PubMed2006

Ornithinibacillus gen. nov., with the species Ornithinibacillus bavariensis sp. nov. and Ornithinibacillus californiensis sp. nov.

A Gram-positive, aerobic, rod-shaped, motile, endospore-forming bacterium was isolated from pasteurized milk from Bavaria, Germany. 16S rRNA gene sequence similarities indicated that strain WSBC 24001(T) was most closely related to Virgibacillus species (95.3-96.1 %), Oceanobacillus species (95.6-95.7 %), Bacillus firmus IAM 12464(T) (95.5 %) and Bacillus niacini IFO 15566(T) (95.2 %). However, strain WSBC 24001(T) showed the highest level of sequence similarity to an unnamed strain, MB-9(T) (97.6 %), which was isolated from coastal surface sediments in California. Hence, this strain was included in our study. The genomic DNA G + C contents of strains WSBC 24001(T) and MB-9(T) were 36.4 mol and 40.8 mol%, respectively. The major respiratory quinone of both strains was menaquinone MK-7 and the peptidoglycan type was A4beta (L-orn<--D-Asp). The polar lipid profiles of these strains contained a predominance of diphosphatidylglycerol and moderate to minor amounts of phosphatidylglycerol, an unknown phospholipid and an unknown aminophospholipid. However, strain WSBC 24001(T) could be distinguished from strain MB-9(T) by the presence of an unknown lipid. The fatty acid profiles of the two strains comprised mainly iso- and anteiso-branched acids, but showed some significant quantitative differences in the amounts of certain acids. The DNA-DNA relatedness value (15.5 %) clearly demonstrated that strains WSBC 24001(T) and MB-9(T) are representatives of two different species. On the basis of their phylogenetic position and morphological, physiological and chemotaxonomic properties, a novel genus is proposed, Ornithinibacillus gen. nov., with two novel species, the type species Ornithinibacillus bavariensis sp. nov. (type strain WSBC 24001(T) = DSM 15681(T) = CCM 7096(T)) and Ornithinibacillus californiensis sp. nov. (type strain MB-9(T) = DSM 16628(T) = CCM 7237(T)).

Catalase↗

PubMed2006

Sources of the adventitious microflora of a smear-ripened cheese.

AIMS: To determine the relationships between the major organisms from the cheese-making personnel and environment and the surface of a smear cheese. METHODS AND RESULTS: 360 yeast and 593 bacteria from the cheese surface, the dairy environment and the hands and arms of personnel were collected. Pulsed-field gel electrophoresis, repetitive sequence-based polymerase chain reaction and 16S rDNA sequencing were used for typing and identifying the bacteria, and mitochondrial DNA restriction fragment length polymorphism and Fourier-transform infrared spectroscopy for typing and identifying the yeast. The three most dominant bacteria were Corynebacterium casei, Corynebacterium variabile and Staphylococcus saprophyticus, which were divided into three, five and seven clusters, respectively, by macrorestriction analysis. The same clones from these organisms were isolated on the cheese surface, the dairy environment and the skin of the cheese personnel. Debaryomyces hansenii was the most dominant yeast. CONCLUSIONS: A 'house' microflora exists in the cheese plant. Although the original source of the micro-organisms was not identified, the brines were an important source of S. saprophyticus and D. hansenii and, additionally, the arms and hands of the workers the sources of C. casei and C. variabile. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first time that the major contribution of the house microflora to the ripening of a smear-ripened cheese has been demonstrated.

Biodiversity↗

PubMed2005

Oxygen ions observed near Saturn's A ring.

Ions were detected in the vicinity of Saturn's A ring by the Ion and Neutral Mass Spectrometer (INMS) instrument onboard the Cassini Orbiter during the spacecraft's passage over the rings. The INMS saw signatures of molecular and atomic oxygen ions and of protons, thus demonstrating the existence of an ionosphere associated with the A ring. A likely explanation for these ions is photoionization by solar ultraviolet radiation of neutral O2 molecules associated with a tenuous ring atmosphere. INMS neutral measurements made during the ring encounter are dominated by a background signal.

Atmosphere↗

PubMed2005

Description and characterization of two new HLA alleles, B4051 and DRB11364, identified by sequence-based typing.

Human leukocyte antigen (HLA)-B and HLA-DRB1 typing in two female individuals revealed reaction patterns that did not correspond to any known HLA-B specificity and appeared to identify a very rare HLA-DRB1 allele, respectively. Sequence-based analysis of these samples revealed two new HLA alleles, one similar to B*4023 and the other to DRB1*1308. The new HLA-B allele, which was assigned the name HLA-B*4051, could have been generated by a double crossing over recombination between B*4001 and B*1401 or 1402, whereas DRB1*1364, the new DRB1 allele, could have been generated either by a double crossing over recombination between DRB1*1308 and DRB1*1201, 1202, or 1203 or by two independent crossing over events between DRB1*1401, DRB1*1201, 1202, or 1203 and DRB1*1301.

Alleles↗

PubMed2004

Universality of the rho meson coupling in effective field theory.

It is shown that both the universal coupling of the rho meson and the Kawarabayashi-Suzuki-Riadzuddin-Fayyazuddin expression for the magnitude of its coupling constant follow from the requirement that chiral perturbation theory of pions, nucleons, and rho mesons is a consistent effective field theory. The prerequisite of the derivation is that all ultraviolet divergences can be absorbed in the redefinition of fields and the available parameters of the most general effective Lagrangian.

Journal Article↗

PubMed2004

Identification of two new HLA alleles: B3546 and B5611. How reliable are the published HLA-B intron 2 sequences?

Polymerase chain reaction-sequence-specific primer (PCR-SSP) typing for human leukocyte antigen (HLA)-B in a male 25-year-old Caucasian individual of Iranian origin and in a 42-year-old German Caucasian bone marrow donor revealed reaction patterns that did not agree with any known HLA specificity, thus suggesting in both cases the existence of a novel allele. Sequence-based typing (SBT) after allelic separation revealed the sequences of the new alleles HLA-B*5611 and B*3546. The sequence patterns of both new alleles might have been generated as the results of double crossing over, possibly over several generations. During the analysis of the HLA-B*3546 intron 2 sequence for possible crossing over points, a base insert, an additional G after position 700, was found. This insert was analyzed using SBT and PCR-SSP and was found to be present not only in all samples carrying B*35, but also in all HLA-B specificities tested. It appears that all known HLA-B alleles may contain a G insert at position 700 of intron 2, and that the published intron 2 sequence alignments of the HLA-B locus may contain errors at this position.

Adult↗

PubMed2004

Visual learning in individually assayed Drosophila larvae.

An understanding of associative learning is facilitated if it can be analyzed in a simple animal like the fruit fly Drosophila. Here, we introduce the first visual associative learning paradigm for larval Drosophila; this is remarkable as larvae have an order of magnitude fewer neurons than adult flies. Larvae were subjected to either of two reciprocal training regimes: Light+/Dark- or Light-/Dark+. Subsequently, all larvae were individually tested for their preference between Light versus Dark. The difference between training regimes was therefore exclusively which visual situation was associated with which reinforcer; differences observed during the test thus reflected exclusively associative learning. For positive reinforcement (+) we used fructose (FRU), and for negative reinforcement (-) either quinine or sodium chloride (QUI, NaCl). Under these conditions, associative learning could be reproducibly observed in both wild-type strains tested. We then compared the effectiveness of training using differential conditioning, with both positive and negative reinforcement, to that using only positive or only negative reinforcement. We found that FRU only, but neither QUI nor NaCl, was in itself effective as a reinforcer. This is the first demonstration of appetitive learning in larval Drosophila. It is now possible to investigate the behavioral and neuronal organization of appetitive visual learning in this simple and genetically easy-to-manipulate experimental system.

Animals↗

PubMed2002

Characterization of a new HLA-A allele, A*0256, identified in a Caucasian individual.

HLA-A typing by the PCR-SSP method in a male 21-year-old Caucasian individual revealed a very rare allele combination corresponding to a unique reaction pattern. Therefore, the result was examined using sequence-based typing. Sequencing of exons 2 and 3 of the HLA-A locus after allelic separation with specific primers revealed the sequence of a new allele, similar to A*0245. Sequencing of exons 1 and 4 resulted in no additional inconclusive positions. The sequence pattern of the new allele HLA-A*0256 might have been generated as a result of a double crossing over recombination of an A*0201 and either an A*03 or an A*11.

Adult↗

PubMed2002

Type II gonadotropin-releasing hormone receptor transcripts in human sperm.

GnRH regulates reproduction via the well-characterized mammalian pituitary GnRH receptor (type I). In addition, two homologous genes for a second form of the GnRH receptor (type II) are present in the human genome, one on chromosome 14 and the second on chromosome 1. The chromosome 14 gene is ubiquitously transcribed at high levels in the antisense orientation but lacks exon 1, required to encode a full-length receptor. In comparison, the chromosome 1 gene contains all three exons. The issue of whether this gene is transcribed in any human tissue(s), and whether these transcripts encode a functional receptor protein, remains unresolved. We have directly addressed this by screening a panel of human RNAs by hybridization and RT-PCR. These analyses showed that, unlike the chromosome 14 gene, chromosome 1 gene expression is limited and of low abundance. Exon 1-containing transcripts were detected by in situ hybridization in mature sperm and in human postmeiotic testicular cells. Further sequence analysis revealed that although all the potential coding segments were present, the human transcripts, like the gene, contain a stop codon within the coding region and a frame-shift relative to other mammalian GnRH receptors. Although this suggests that the human gene may be a transcribed pseudogene, a functional type II GnRH receptor cDNA has recently been cloned from monkeys. Given the well-established role of GnRH in spermatogenesis and reported evidence of type II GnRH receptor immunoreactivity in human tissues, it is possible that the chromosome 1 gene is functional.

Amino Acid Sequence↗

PubMed2001

Genetic mapping and DNA sequence-based analysis of deleted regions on chromosome 16 involved in progression of bladder cancer from occult preneoplastic conditions to invasive disease.

Histologic and genetic mapping with 30 hypervariable markers mapped to chromosome 16 were performed on 234 DNA samples of five cystectomy specimens from patients with invasive bladder cancer. Allelic losses of individual markers were related to microscopically identified precursor conditions in the entire bladder mucosa and invasive cancer. Their significance for the development and progression of neoplasia from in situ preneoplastic conditions to invasive disease was analysed by the nearest neighbor algorithm and binomial maximum likelihood analysis. Using this approach we identified five distinct regions of allelic losses defined by their flanking markers and predicted size as follows. p13.3(D16S418-D16S406, 1.2 cM), p13.1(D16S748-D16S287, 12.9 cM), q12 1(D16S409-D16S514, 24.0 cM), q22.1 (D16S496-D16S515, 5.4 cM), and q24 (D16S507-D16S511, 5.9 cM and D16S402-D16S413, 17.4 cM). The regions mapping to p13.1 and q24 were involved in early intraurothelial phases of bladder neoplasia such as mild to moderate dysplasia. On the other hand the deleted region mapping to p13.3 was involved in progression of severe dysplasia/carcinoma in situ to invasive bladder cancer. Testing of markers that exhibited statistically significant LOH in relation to progression of neoplasia from precursor conditions to invasive cancer on 28 tumors and voided urine samples from 25 patients with bladder cancer revealed that q12.1 showed LOH in 46.4% of tumor and 32.0% of voided urine samples. The LOH of a single marker D16S541 could be detected in approximately 28% of tumors and 20% of voided urine samples of patients with bladder cancer. These data imply that the deleted region centered around marker D16S541 spanning approximately 10 cM and flanked by D16S409 and D16S415 contains a novel putative tumor suppressor gene or genes playing an important role in the development of human bladder cancer. To facilitate more precise positional mapping and identification of pathogenetically relevant genes, we analysed of human genome contig and sequence databases spanning the deleted regions. Multiple known candidate genes and several smaller gene-rich areas mapping to the target regions of chromosome 16 were identified.

Aged↗

PubMed2001

The effects of altitude on heavy-duty diesel truck on-road emissions.

On-road measurements of carbon monoxide, hydrocarbons, and nitric oxide from 5772 heavy-duty diesel trucks at five locations in the United States and Europe show slightly increasing emissions with increasing altitude. The result for nitric oxide showed a statistically significant increase of 4.1 +/- 1 gNO/kg of fuel consumed/km increase in altitude. The increases for CO and HC were also statistically significant.

Air Pollutants↗

PubMed2001

Genomic evidence for a complete sexual cycle in Candida albicans.

Candida albicans is a diploid fungus that has become a medically important opportunistic pathogen in immunocompromised individuals. We have sequenced the C. albicans genome to 10.4-fold coverage and performed a comparative genomic analysis between C. albicans and Saccharomyces cerevisiae with the objective of assessing whether Candida possesses a genetic repertoire that could support a complete sexual cycle. Analyzing over 500 genes important for sexual differentiation in S. cerevisiae, we find many homologues of genes that are implicated in the initiation of meiosis, chromosome recombination, and the formation of synaptonemal complexes. However, others are striking in their absence. C. albicans seems to have homologues of all of the elements of a functional pheromone response pathway involved in mating in S. cerevisiae but lacks many homologues of S. cerevisiae genes for meiosis. Other meiotic gene homologues in organisms ranging from filamentous fungi to Drosophila melanogaster and Caenorhabditis elegans were also found in the C. albicans genome, suggesting potential alternative mechanisms of genetic exchange.

Animals↗

PubMed2001

Experimental annotation of the human genome using microarray technology.

The most important product of the sequencing of a genome is a complete, accurate catalogue of genes and their products, primarily messenger RNA transcripts and their cognate proteins. Such a catalogue cannot be constructed by computational annotation alone; it requires experimental validation on a genome scale. Using 'exon' and 'tiling' arrays fabricated by ink-jet oligonucleotide synthesis, we devised an experimental approach to validate and refine computational gene predictions and define full-length transcripts on the basis of co-regulated expression of their exons. These methods can provide more accurate gene numbers and allow the detection of mRNA splice variants and identification of the tissue- and disease-specific conditions under which genes are expressed. We apply our technique to chromosome 22q under 69 experimental condition pairs, and to the entire human genome under two experimental conditions. We discuss implications for more comprehensive, consistent and reliable genome annotation, more efficient, full-length complementary DNA cloning strategies and application to complex diseases.

Algorithms↗

PubMed2001

A physical map of the human genome.

The human genome is by far the largest genome to be sequenced, and its size and complexity present many challenges for sequence assembly. The International Human Genome Sequencing Consortium constructed a map of the whole genome to enable the selection of clones for sequencing and for the accurate assembly of the genome sequence. Here we report the construction of the whole-genome bacterial artificial chromosome (BAC) map and its integration with previous landmark maps and information from mapping efforts focused on specific chromosomal regions. We also describe the integration of sequence data with the map.

Chromosomes, Artificial, Bacterial↗

PubMed2001

A high-resolution map of human chromosome 12.

Our sequence-tagged site-content map of chromosome 12 is now integrated with the whole-genome fingerprinting effort. It provides accurate and nearly complete bacterial clone coverage of chromosome 12. We propose that this integrated mapping protocol serves as a model for constructing physical maps for entire genomes.

Chromosomes, Artificial, Bacterial↗

PubMed2001

High incidence of Listeria monocytogenes in European red smear cheese.

The incidence of Listeria and Listeria monocytogenes in European red smear cheese was determined in order to assess whether the lack of recent outbreaks of listeriosis associated with cheese is due to improved hygenic conditions in the dairies. Out of European red-smear cheese samples of various types, 15.8% contained organisms of the genus Listeria, 6.4% of the samples were contaminated with L. monocytogenes, 10.6% with L. innocua, and 1.2% with L. seeligeri. Six cheese samples contained two or more Listeria species, including at least one L. monocytogenes isolate. The incidences of L. monocytogenes in cheeses from various countries were: Italy 17.4%, Germany 9.2%, Austria 10%, and France 3.3%. Listeria were found most frequently in soft and semi-soft cheese. Eight samples contained more than 100 L. monocytogenes cfu/cm2 cheese surface, 2 samples had counts above 10(4) cfu/cm2 cheese surface. Surprisingly, a higher incidence of L. monocytogenes was observed in cheeses made from pasteurized milk (8.0%) than in cheeses manufactured from raw milk (4.8%). Phage-typing of isolated Listeria strains clearly confirmed that (i) contaminations within dairy plants were persistent over a period of several weeks to months and (ii) that cross-contamination within the dairy plant is and important factor. Comparison of our data with past surveys seems to indicate that contamination of red smear soft cheese with L. monocytogenes has not decreased sufficiently over the past 15 years. It is therefore strongly recommended that these products are monitored carefully by cheese-making companies.

Animals↗

PubMed2001

Human leukocyte antigen class II allele frequencies and haplotype association in Iranian normal population.

The polymorphism of the HLA class II genes DRB1, DQA1, and DQB1 was investigated in 100 unrelated Iranian individuals from Fars province in Southern Iran, using the restriction fragment length polymorphism (RFLP) method. Subtyping of DRB1*04, *15, and *16 alleles was performed using PCR amplification with sequence specific primes (PCR-SSP). The allele and the haplotype frequencies were calculated. The most common DRB1 alleles were DRB1*11, DRB1*15, and DRB1*04 with a frequency of 25.0%, 14.5%, and 10.5%, respectively. In contrast, the allelic frequency of DRB1*12 and DRB1*08 was very low (1.5% for each). In the DR15 group DRB1*1501 was the most prevalent variant (6.0%). Concerning DR4, the most common alleles were DRB1*0405 and DRB1*0402 (3.5% for each). Interestingly, DRB1*0402 was associated with DQB1*0302 and DRB1*0405 was associated with DQB1*0302 and DQB1*02, the latter being a rare DRB1/DQB1 haplotype in Caucasian individuals. The most frequent DQB1 alleles were DQB1*0301 (31.0%), and DQB1*05 (22.0%). The most frequent DQA1 variants were DQA1*0501 (39.0%) and DQA1*0102 (14.5%). The most common haplotype was DRB1*11-DQB1*0301-DQA1*0501 (25.0%) followed by DRB1*0301-DQB1*02-DQA1*0501 (10%) and DRB1*0701- DQB1*02-DQA1*0201 (6.5%). Data presented in this study suggest that the Iranian population shares some HLA components with populations resident in eastern and southern European countries.

Alleles↗

PubMed2001

Preservation of products with MCI/MI in Switzerland.

Preservation of products with the combination of 5-chloro-2-methyl-4-isothiazolinone (methylchloroisothiazolinone, MCI) and 2-methyl-4-isothiazolinone (methylisothiazolinone, MI), commercialized as Kathon CG or WT, is widely used. Allergic contact dermatitis reactions to the preservative have been described in many publications of epidemiological studies. In addition, a number of allergic, airborne reactions to MCI/MI were observed in recent years. The aim of the presented study was: (i) to compare epidemiological data of MCI/MI with data of other preservatives; (ii) to estimate the possible exposure to MCI/MI from commercial products and the distribution of MCI/MI in chemical products based on a product evaluation of the chemical product register of the Swiss Federal Office of Public Health; (iii) to estimate the exposure to MCI/MI, volatile organic chemicals (VOC) and glycols from freshly painted walls; (iv) to compare the contact allergenic potential of MCI/MI with other preservatives. It was found that the number of registered chemical products, unambiguously identifiable as containing MCI increased from 3644 products in July 1999 to 4843 products in April 2001 in Switzerland. It is estimated that today, the total number of chemical products preserved with MCI/MI on the Swiss market is about 6000. A further increase is to be expected. The contact allergenic potential of MCI/MI seems to be higher than for other preservatives. Measurements of MCI/MI concentrations in air samples of freshly painted rooms have shown that the concentration of MCI/MI in the air a few days after painting may be high enough to elicit airborne reactions in already-sensitized patients. In a single case, reactions to MCI/MI were observed over months after wall painting. In this case, both wall paint and plaster contained MCI (40 and 46 ppm). Volatile organic chemicals (VOC) may also be relevant for the elicitation of airborne reactions. In 1/3 of the measurements, the VOC concentrations measured within 14 days after painting were in a range within which sensory irritation and discomfort may be induced. Declaration of MCI/MI-containing products, replacement of MCI/MI by alternative preservatives or the separate use of preservatives in industrial products and in cosmetics might reduce the risk of airborne reactions.

Air Pollution, Indoor↗