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Copyright of Manuelle Medizin is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Coagulase-negative staphylococci (CoNS) are the most prevalent pathogens causing late-onset sepsis in neonates. The question is whether neonates acquire endemic hospital-adapted clones or incidentally occurring CoNS strains after birth during their hospital stay. Therefore, a prospective study was performed on the prevalence of CoNS in the stool of babies (born vaginally or by cesarean section) during their first days of life. Their clonal relatedness and potential to induce invasive disease were characterized. CoNS were analyzed from the stool samples of newborns with a load of CoNS above 10 colony-forming units (CFU)/mL. The identification of CoNS was performed phenotypically and genotypically. For typing, repetitive polymerase chain reaction (PCR), pulsed-field gel electrophoresis, and multilocus sequence typing were used. Resistance profiles, biofilm production, the presence of icaAD and of IS256 were determined as well. From a total of 207 stool samples (56 newborns), CoNS were detected in 41% of the newborns, mostly on day 3 for the first time (62.5%). Staphylococcus epidermidis was isolated in 85.7% of cases, harbored no IS256 element, and mostly expressed no biofilm. The isolates were separated into four main clusters by repetitive sequence-based PCR. 24% of the strains showed no antimicrobial resistance. 20% were resistant against four antibiotics of two different antibiotic classes. The remaining strains were resistant only against one antimicrobial substance class. Thus, it can be concluded that newborns do not acquire hospital-adapted endemic, multidrug-resistant S. epidermidis isolates during their first days of life. Yet, the results support the thesis that, during hospital stay, environmental parameters may convert sensible/noninvasive S. epidermidis strains into multidrug-resistant strains with characteristics of invasiveness. [ABSTRACT FROM AUTHOR]

Purpose: Anemia and vitamin D deficiency are both frequent in adult patients. Whether low vitamin D metabolite levels are an independent risk factor for different subtypes of anemia remains to be studied in detail. Methods: In 3299 patients referred for coronary angiography, we investigated the association of 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D [1,25(OH)D] with anemia [hemoglobin (Hb) <12.5 g/dl] of specific subtypes. Results: Compared with patients with 25OHD levels in the adequate range (50-125 nmol/l), patients with deficient 25OHD concentrations (<30 nmol/l; 33.6 % of patients) had 0.6 g/dl lower Hb levels. Hb values were 1.3 g/dl lower in patients with 1,25(OH)D levels <40 pmol/l (5.4 % of patients), compared with patients in the highest 1,25(OH)D category (>70 pmol/l). Of the participants, 16.7 % met the criteria for anemia. In multivariate-adjusted regression analyses, the odds ratios for anemia in the lowest 25OHD and 1,25(OH)D categories were 1.52 (95 % CI 1.15-2.02) and 3.59 (95 % CI 2.33-5.52), compared with patients with 25OHD levels in the adequate range and patients with 1,25(OH)D levels >70 pmol/l. The probability of anemia was highest in patients with combined 25OHD and 1,25(OH)D deficiency [multivariable-adjusted odds ratio 5.11 (95 % CI 2.66-9.81)]. Patients with anemia of chronic kidney disease had the highest prevalence of 25OHD deficiency and 1,25(OH)D concentrations of <40 pmol/l. Conclusions: Low 25OHD and 1,25(OH)D concentrations are independently associated with anemia. Patients with poor kidney function are most affected. Interventional trials are warranted to prove whether administration of plain or activated vitamin D can prevent anemia. [ABSTRACT FROM AUTHOR]

We consider random Schrödinger operators of the form $${\Delta+\xi}$$ , where $${\Delta}$$ is the lattice Laplacian on $${\mathbb{Z}^{d}}$$ and $${\xi}$$ is an i.i.d. random field, and study the extreme order statistics of the Dirichlet eigenvalues for this operator restricted to large but finite subsets of $${\mathbb{Z}^{d}}$$ . We show that, for $${\xi}$$ with a doubly-exponential type of upper tail, the upper extreme order statistics of the eigenvalues falls into the Gumbel max-order class, and the corresponding eigenfunctions are exponentially localized in regions where $${\xi}$$ takes large, and properly arranged, values. The picture we prove is thus closely connected with the phenomenon of Anderson localization at the spectral edge. Notwithstanding, our approach is largely independent of existing methods for proofs of Anderson localization and it is based on studying individual eigenvalue/eigenfunction pairs and characterizing the regions where the leading eigenfunctions put most of their mass. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift für Herz-, Thorax- und Gefaesschirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Single crystals of lead telluride doped with Nd were synthesized using the Bridgeman method. Room temperature far infrared reflectivity spectra were measured for PbTe samples with Nd content in the range 0.2–0.9 at.%. Optical reflectivity in the far infrared range was measured in the temperature range between 10 and 300 K for a highly polished PbTe sample with 0.6 at.% Nd. The experimental diagrams were numerically analyzed with a fitting procedure using a modified plasmon–phonon model. Two local modes were noted and their origin was discussed. Optical electron mobility was calculated for all analyzed samples. [ABSTRACT FROM AUTHOR]

Copyright of Manuelle Medizin is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Heterogeneous methicillin-resistant Staphylococcus aureus (MRSA) strains, including community-acquired MRSA strains, have been observed in Central Europe. The purpose of this study was to characterize by molecular methods MRSA isolated during the period 2002–2003 at the Otto-von-Guericke University Hospital in Magdeburg, Germany, and at a nearby chronic care facility. Strains were analyzed for their resistance phenotype. Selected isolates were typed by multilocus sequence typing (MLST), by a multiplex polymerase chain reaction (PCR) for the staphylococcal cassette chromosome mec (SCC mec), by an allele-specific PCR for the staphylococcal accessory gene regulator ( agr), and by PCR for the presence of toxin genes ( sea– sej, tsst-1, hlgA, C, and B, lukE/D, and luk-pvl). Of the 2,731 S. aureus isolates studied, 199 (7.3%) were MRSA, with a prevalence of 21.6%, 19.6%, and 12% in the department of dermatology, the chronic care facility, and the intensive care units. Six different sequence types (ST247, ST228, ST22, ST22a, ST225, and ST45) were observed. Of these, ST22, ST22a, and ST45 dominated (>50%) in the department of dermatology and the chronic care facility. Strains with these sequence types were usually not resistant to gentamicin and were associated with agr group I, the SCC mec type IV element, and the presence of the sec and sed toxin genes. ST228 strains were found mainly in the intensive care units and had a broader resistance phenotype and were associated with agr group II and the SCC mec type I element. All luk-pvl-positive MRSA isolates ( n=8) belonged to agr group I and were typed as ST22 or ST45 and contained the SCC mec type I ( n=1), type III ( n=1), or type IV ( n=6) element. The main observations of this study are in concordance with previously reported findings showing dissemination of MRSA in Central Europe. Through the multitude of applied methods, the data from this study contribute to a more precise knowledge about the heterogeneity of MRSA in a clinical setting. Rapid dissemination of MRSA clones at a university hospital was demonstrated, indicating that dissemination may depend on the environmental conditions within the individual departments. [ABSTRACT FROM AUTHOR]

An 11-year-old patient with anamnestic fever for 3 days and signs of upper respiratory tract infection underwent fulminant Staphylococcus aureus pneumonia with concomitant agranulocytosis. From autopsia influenza B virus and parvovirus B19 were detected by nucleic acid amplification technique (NAT). Specific IgG but no IgM points to preexisting parvovirus B19 infection. Whether in this case agranulocytosis can be interpreted as early manifestation of reactivated parvovirus B19 infection is under discussion. Therefore, parvovirus B19 could have provoked a foudroyant course of influenza B pneumonia which was superinfected with S. aureus. [ABSTRACT FROM AUTHOR]

Specificity of olfactory receptor neurones plays an important role in food and host preferences of a species, and may have become conserved or changed in the evolution of polyphagy and oligophagy. We have identified a major type of plant odour receptor neurones responding to the sesquiterpene germacrene D in three species of heliothine moths, the polyphagous Heliothis virescens and Helicoverpa armigera and the oligophagous Helicoverpa assulta. The neurones respond with high sensitivity and selectivity to (–)-germacrene D, as demonstrated by screening via gas chromatography with numerous mixtures of plant volatiles. Germacrene D was present in both host and non-host plants, but only in half of the tested species. The specificity of the neurones was similar in the three species, as shown by the "secondary" responses to a few other sesquiterpenes. The effect of (–)-germacrene D was about ten times stronger than that of the (+)-enantiomer, which again was about ten times stronger than that of (–)-α-ylangene. Weaker effects were obtained for (+)-β-ylangene, (+)-α-copaene, β-copaene and two unidentified sesquiterpenes. The structure-activity relationship shows that the important properties of (–)-germacrene D in activating the neurones are the ten-membered ring system and the three double bonds acting as electron-rich centres, in addition to the direction of the isopropyl-group responsible for the different effects of the germacrene D enantiomers. [ABSTRACT FROM AUTHOR]

Background: Microorganisms become attracted to polymer surfaces for a number of reasons including positive charge of biomaterial or concentration of nutrients on the biomaterial surface. Many bacteria aditionally possess specific receptors for the interaction with extracellular host protein components that adhere on the biomaterial surface. Several authors suggest that application of closed in-line polypropylene suction catheters (CISC) in intubated patients for more than 24 h is safe and can reduce the costs associated with mechanical ventilation. Therefore, we evaluated the possible role of prolonged application of CISC to cause enhanced colonization of both the biomaterial and the lower respiratory tract. Materials and Methods: The prospective, randomized study included 23 mechanically ventilated patients. The CISC tips, adjacent segments and tracheobronchial aspirates of each patient were examined for microbial growth. Results: Application for 72 h significantly enhanced the microbial growth on the CISC tips and on the adjacent catheter segment. Usage for 3 days led to a significant increase in colonization in the lower respiratory tract. Conclusion: Normal saline instillation in conjunction with endotracheal suctioning may lead to a dispersion of microorganisms into the lower respiratory tract. More effective self-cleaning mechanisms are necessary to decontaminate the CISC surface after suctioning. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift für Herz-, Thorax- und Gefaesschirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A method for the enantioselective separation of the chiral polycyclic musks HHCB, AHTN, AHDI, and ATII is presented. Eighteen fish samples (rudd, tench, crucian carp, eel) and one pooled zebra mussel sample from the pond of a municipal sewage treatment plant were investigated with regard to their concentrations and the enantiomeric ratios (ERs) of polycyclic musks. In addition, three water samples taken at the effluent of the sewage plant, as well as two water samples and two series of semipermeable membrane devices (SPMDs) consisting of six samples each from the pond were included in the present study. This comprehensive data set allowed a reliable evaluation of species-dependent metabolization processes. The pattern of the polycyclic musks in the chromatograms obtained by enantioselective gas chromatography seems to be typical of each species, like a fingerprint. The highest deviations from the racemic ER were found for trans-HHCB and trans-ATII in crucian carp with values of or below 0.1. Calculations showed that enantioselective transformation seems to be the most important process, resulting in the observed lower concentrations in crucian carp compared to tench. Consequences for a risk assessment are discussed. [ABSTRACT FROM AUTHOR]

Background: Rapid and reliable identification of micro-organisms is a prerequisite for the diagnosis and subsequent treatment of infectious diseases. The identification of pathogenic bacteria is traditionally based on their isolation from clinical samples and propagation on culture medium in the routine laboratory. However, despite clinical signs of infection, culture of the pathogenic agent often fails. This may be due to a low number of microorganisms, prior antibiotic treatment, nonculturable microorganisms or specific culture requirements for presently unknown pathogens. Amplification and sequencing of the entire prokaryotic 16S-rRNA is time consuming, labor intensive and expensive. Materials and Methods: We describe here a procedure for the identification of a wide range of known and unknown clinically relevant microorganisms by sequencing a small, but highly informative region of the prokaryotic 16S-rRNA gene. This rapid ribosequencing method was evaluated with various reference strains and with clinical, samples including eye anterior chamber fluid, cerebrospinal. fluid (CSF) and blood cultures. Results: All, sequences obtained from the reference strains corresponded to the sequences in databases. We correlated severe eye infection with the isolation of Pseudomonas putida, neurological. disorder with Tropheryma whippelii and disseminated visceral, abscesses in a child with Blastobacter den itrificans. Conclusion: We consider the rapid ribosequencing method as a promising new tool for the analysis of infectious agents in primarily sterile body fluids where conventional, culturing of microorganisms fails. [ABSTRACT FROM AUTHOR]

We consider the parabolic Anderson problem ∂[sub t] u = κΔu + ξ(x)u on ℝ[sub +] x ℝ[sup d] with initial condition u(0,x) = 1. Here κ > 0 is a diffusion constant and ξ is a random homogeneous potential. We concentrate on the two important cases of a Gaussian potential and a shot noise Poisson potential. Under some mild regularity assumptions, we derive the second-order term of the almost sure asymptotics of u(t, 0) as t → ∞. [ABSTRACT FROM AUTHOR]

Copyright of Umweltwissenschaften und Schadstoff-Forschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recently, we described the presence of a blocking factor (BF) in rat serum which inhibited the histamine release from rat mast cells in vivo and in vitro. The blocking activity was demonstrated in human serum as well. Purification of the human-BF was carried out in a similar way as previously described for the rodent molecule. Both protein fractions produced a marked suppression of histamine release from rat mast cells and human basophils in a dose-dependent fashion. Qualitative analysis of the purified preparations demonstrated a major component with a molecular weight of 70 000 daltons. In human serum the blocking factor was identified as transferrin by serological and biochemical methods. It is suggested that this molecule may play an important role in regulating histamine release during allergic and inflammatory reactions. [ABSTRACT FROM AUTHOR]

The close relation between rat mast cells and rat basophilic leukemia (RBL) cells with regard to the presence of receptors for IgE and Fcγ led us to generate monoclonal antobodies directed against cell surface antigens. Hybridomas were obtained by the fusion of NS1 mouse myeloma cells with murine spleen and lymph node cells. The culture supernatants were assayed by two ELISA techniques: a) for the production of mouse immunoglobulin in general and b) for antibodies directed against surface antigens of RBL cells. For this purpose RBL cells were attached to polyvinyl chloride microtitre plates. Eight hybrids produced antibodies directed against surface antigens on RBL cells. Hybrids were cloned and characterized with regard to their isotype and light chains. All eight clones secreted IgM with K light chains. Immunofluorescence studies performed with RBL cells revealed that all eight antibodies were able to show a specific fluorescence. Furthermore, four of these eight antibodies also showed a specific fluorescence with purified rat mast cells. These four antibodies were analyzed as to their ability of interacting with the IgE-receptor on RBL cells and purified rat mast cells. They reduced the binding rate of radiolabelled rat IgE to RBL and rat mast cells. A mutual inhibition of the passive cutaneous anaphylaxis (PCA) reaction in the rat by either mixing mouse reaginic serum directed against 2,4-dinitrophenol bovine serum albumin (DNP-BSA) or by mixing monoclonal mouse anti-DNP IgE with the monoclonal mouse anti-cell surface (rat basophilic leukemia, rat mast cell) IgM was determined. The histamine release of rat mast cells obtained from Nippo-strongylus brasiliensis infected rats was markedly reduced in the presence of two monoclonal anti cell surface antibodies. Our data suggest that monoclonal antibodies with specificity for the IgE receptor (inhibition of IgE-binding) can be distinguished from those which bind closely to the IgE-receptor but also modulate the histamine release from presensitized mast cells. [ABSTRACT FROM AUTHOR]

Mast cells from normal rats and animals reinfected with Nippostrongylus brasiliensis (N.b.) were sensitized in vitro with monoclonal anti-DNP mouse IgE, reaginic mouse serum with ovalbumin (OA) specificity and reaginic rat serum against N.b. The sensitized cells were triggered for the release of histamine with DNP-bovine-serum-albumin (DNP-BSA), OA, N.b.-homogenate and guinea-pig antimouse IgE. The histamine release from normal mast cells sensitized with monoclonal mouse IgE was inhibited either with N.b.-reaginic rat serum or OA-reaginic mouse IgE (30μg/10 mast cells) completely densensitized mast cells from reinfected rats for specific histamine release in the presence of either N.b.-antigen or DNP-BSA. Anti-mouse IgE which was prepared by monoclonal mouse IgE did not bind to rat mast cells sensitized with rat IgE as was revealed by immunofluorescence experiments. Consequently we observed that anti-mouse IgE failed to trigger the histamine release from mast cells of reinfected rats. [ABSTRACT FROM AUTHOR]

Copyright of Infection is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In all the species of the Cataglyphis bicolor group examined yet, i.e. C. bicolor, C. diehli, C. isis, C. nodus, and C. viaticus, 2-methyl-1-hexanol is the characteristic substance and almost the only substance found in the mandibular glands. Its chirality has been determined in C. bicolor and shown to be exclusively ( S)-2-methyl-1-hexanol. [ABSTRACT FROM AUTHOR]

The far-infrared absorption spectrum (20-250cm) of the superionic conductor LiN -withLi- andLi-isotopes in the starting material-has been measured for different polarizations and temperatures (4-150 K). The E ⊥ c spectrum yields two lines near 80 and 140 cm, which are not observed for E ⊥ c. From the isotopic frequency ratio ( ω/ ω≃1.07) and from the comparison to lattice dynamics it is concluded that these lines are due to resonant modes, weakly coupled to the lattice. Measurements of the isotope effects on the dielectric properties (10 Hz to 1 MHz) establish that the local diffusive type motion in shallow potentials and the low lying resonant modes originate from the same defect system (including Li-ions in non-regular positions). [ABSTRACT FROM AUTHOR]

Copyright of Archiv für Mikrobiologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The role of lipoxygenase products was studied in children suffering from chronic diseases of the lung. Leukotrienes C, D, E and B were measured by high performance liquid chromatography (HPLC) and a specific radioimmunoassay (RIA) for C. Elevated levels (up to 40 ng/ml), especially for leukotriene E, were found in plasma of asthmatic and bronchitic patients (leukotriene C concentrations varied between 0.05 and 40 ng/ml, mean 4.9±7.8 ng/ml). In healthy donors the concentrations were below the detection limits of HPLC, leukotriene C ranging between 5±4 ng/ml (RIA data). The conversion of leukotriene C to D and E was observed by incubating the samples with synthetic leukotriene C. The half-life of leukotriene C in plasma varied greatly, ranging from <12 min to 72 min (mean 39±16 min). Bronchial lavages yielded leukotriene C concentrations of 0.2 to 7 ng. Leukotriene E was detected in 10 of 41 cases. Conversion of leukotriene C did not occur in 50% of all cases, but was regularly observed in putrid lavages. These data suggest that leukotrienes play an important role in allergic and infectious lung diseases. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Dermatological Research is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The influence of nicotine and its main metabolite cotinine on the spontaneous and cytokine-induced immunoglobulin synthesis was studied. The immunoglobulin (G,A) synthesis of peripheral blood mononuclear cells was altered by nicotine donor dependently in the concentration range from 10-6 to 10 M. Cotinine also modulates immunoglobulin (G, A) synthesis. The effective concentration range is about 100 fold higher. Only marginal effects on IgM synthesis were observed. Neither nicotine nor cotinine showed any effect on IgE production or on the IgE class switch. Moreover, both agents induced the production of the cytokines interleukin-1α, −2, −3, −4, and −6. Therefore it is suggested that the strongly donor-dependent heterogeneity in the response to nicotine or cotinine is the result of the fine balance of theinduced cytokines. [ABSTRACT FROM AUTHOR]

The Neotropical species Pachycondyla marginata conducts well-organized predatory raids on the termite species Neocapritermes opacus and frequently emigrates to new nest sites. During both activities the ants employ chemical trail communication. The trail pheromone orginates from the pygidial gland. Among the substances identified in the pygidial gland secretions, only citronellal was effective as a trail pheromone. Isopulegol elicited an increase in locomotory activity in the ants and may function as a synergist recruitment signal. The chemical signal is enhanced by a shaking display performed by the recruiting ant. [ABSTRACT FROM AUTHOR]

We analyzed DNA-fragmentation in human polymorphonuclear neutrophil granulocytes (PMNs) from healthy donors after addition of exogenous arachidonic acid (AA) and eicosapentaenoic acid (EPA) by flow cytometry (propidium iodide staining of DNA and DNA strand break detection). The PMNs were incubated from 30 min up to 48 hours in RPMI 1640 which was supplemented with different concentrations of AA or EPA (5–40 μM). In contrast to EPA the addition of AA led to a significant increase in apoptosis up to 67.8% compared to the RPMI-control whereas the addition of EPA led to an inhibition of DNA-fragmentation. When the cells were incubated with MK 886 (1μM, inhibitor of leukotriene biosynthesis) an increase in DNA-fragmentation (up to 63.3%) was observed. Conversely, in the presence of indomethacin (1μM, inhibitor of prostanoid synthesis) an inhibition in DNA-fragmentation (up to 60.9%) occurred. Furthermore, preincubation of PMNs with pentoxifylline (1mM, phosphodiesterase inhibitor) reduced AA-stimulated DNA-fragmentation up to 43.4%. These data provide evidence for the involvement of AA and distinct AA metabolites in the regulation of apoptosis in human PMNs. [ABSTRACT FROM AUTHOR]

The differential cross section of the deuteron photodisintegration was measured at a protion c.m. angle of 180 degrees and for photon energies between 180 and 730 MeV. The protons were detected in a magnetic spectrometer. The proton energy resolution varied between 30 MeV and 50 MeV FWHM. Since these are the first data at 180 degrees in this energy range a comparison can only be done with data from other laboratories extrapolated to 180 degrees and with theoretical predictions. The agreement with existing calculations is poor. Contributions of dibaryons to the cross section seem not to improve the situation. [ABSTRACT FROM AUTHOR]

Toxic and nontoxic peptides were isolated from the cyanobacterium Microcystis aeruginosa PCC 7806 by a procedure including extraction of cells with water-saturated 1-butanol, chromatography of the extract on silica gel plates and high performance liquid chromatography (HPLC) on Partisil-5. The toxin was shown to be only a minor constituent, being negatively charged and thus separable by electrophoresis, within the HPLC-purified fraction. It contained erythro-β-methyl- D-Asp, D-Glu, D-Ala, L-Leu, and L-Arg known to be part of the Microcystis peptide-toxin with M 994. The major part of the HPLC-purified fraction was assigned, however, to a nontoxic peptide with a M of 956. Partial hydrolysis studies of the nontoxic peptide(s) revealed amino acid sequences composed of D-Glu, N-methyl-Phe, and 3,4-dehydro-Pro, aside from the common L-amino acids. Cyclic linkage in the nontoxic peptide(s) appears likely. [ABSTRACT FROM AUTHOR]

L-Ornithine is the only diamino acid of the peptidoglycan of the gliding phototrophic Chloroflexus aurantiacus. The other constituents are L- and D-alanine, D-glutamic acid, N-acetyl-glucosamine and N-acetyl-muramic acid (in part as muramic acid-6-phosphate), all in approximate equimolar ratios to L-ornithine, aside from small amounts of glycine and histidine. Furthermore unlike typical Gram-negative bacteria, protein is not bound to this peptidoglycan. Instead, the rigid layer (sodium dodecyl sulfate insoluble cell wall fraction) contained large amounts of a complex polysaccharide consisting of sugar O-methyl ethers, hexoses and pentoses. Its binding site is presumably muramic acid-6-phosphate of the peptidoglycan. In contrast, in Chlorobium vibrioforme f. thiosulfatophilium, meso-diaminopimelic acid was found as the only diamino acid of this peptidoglycan. As with other Gramnegative bacteria, L- and D-alanine, D-glutamic acid, N-acetyl-glucosamine and N-acetyl-muramic acid (no muramic acid-6-phosphate) were observed in approximate equimolar ratios to meso-diaminopimelic acid, except a lower D-alanine content. The rigid layer of Chlorobium vibrioforme f. thiosulfatophilum contained protein, and there were no indications for a complex polysaccharide comparable to that of Chloroflexus aurantiacus. [ABSTRACT FROM AUTHOR]

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Copyright of Archives of Microbiology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archives of Microbiology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archives of Microbiology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The characteristics of mobile radio channels place fundamental limits on the performance of mobile radio communication systems. Reliable information about these characteristics are obtained in this paper by analysing wideband propagation measurements, which were performed by using an high performance wideband channel sounder in mountainous areas in the German Alps and in typical urban areas in Munich. In addition to well known results obtained from propagation measurements in similar scenarios [1, 2], novel aspects of practical relevance enable for a realistic analysis of the performance of mobile radio systems in terms of the discussed channel parameters and support a compromise between system costs and the quality of signal processing with respect to the system availability and reliability. [ABSTRACT FROM AUTHOR]

An eddy effect of tropical deep convection on the large-scale momentum, resp vorticity budget is investigated. The process is specified by a simple parameterization approach which is based on a concept of rotating clouds exerting a momentum on the large-scale flow. The cloud rotation is associated with the thermal properties of a cloud ensemble by the principle of conservation of potential vorticity. A decomposition of cloud classes is applied in consistency with the thermodynamical parameterization scheme of Arakawa and Schubert (1974). The parameterization is tested with observations of GATE74, Phase III. The data are processed on a B/C-scale grid (55km) in a region within 9N and 16N, and between 21W and 27W, and with a vertical resolution of 41 levels. The parameterization results correspond to the observed patterns, especially in situations with strong large-scale wind shear. The findings suggest that certain large-scalle flow regimes provoke convective scale momentum generation rather than redistributing large-scale momentum by convective circulations. [ABSTRACT FROM AUTHOR]

The effects of clouds on the large-scale vorticity budget are parameterized in terms of cloud mass flux and momentum differences between the cloud ensemble and the large-scale environment. The cloud mass flux distribution is calculated using the parameterization scheme of Arakawa and Schubert (1974). For the determination of the momentum effects of a cloud ensemble, three different parameterization concepts are developed: first, constant momentum in the cloud which is injected from the environment in the convergence layer of the lower troposphere; second, a generation of a vortex couplet induced by the tilting of horizontal vorticity components; third, drag effects of clouds which interact with the large-scale flow. The computed momentum effects from each of the three parameterizations are compared with the residual of the large-scale vorticity budget for B/C-scale observations during GATE 74 Phase III using a composite technique. With moderate convection and wind shear best results are achieved by the description of the vortex couplet; intense convection and small wind shear are best explained by the constant cloud momentum model; the drag of the clouds on the large-scale flow appears to dominate during periods of weak convection. [ABSTRACT FROM AUTHOR]

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In vitro IgE synthesis by lymphoid cells was studied during the course of infection of mice with Nippostrongylus brasiliensis. The studies involved inbred strains of mice which had been shown to be high IgE responders (A.CA, B10.M), or non-responders (Balb/c, B10.D2) to parasite antigen. In addition, F hybrids of low and high responders and irradiated non-responders were studied. Infection with N. brasiliensis led to an increase in IgE synthesis in vitro which was most pronounced during reinfection of mice. Addition of mitogens e.g. pokeweed mitogen (PWM), lipopolysaccharide (LPS), concanavalin A (ConA) to the cultures induced enhancement, suppression or had no effect on IgE synthesis. Addition of N. brasiliensis homogenate or worm culture supernatant led to a fluctuating pattern of IgE synthesis. No correlation was found between lymphocyte proliferative response to mitogen and worm antigens and IgE synthesis. Our data suggest, that PWM is more likely to enhance IgE synthesis in vitro than LPS or ConA. An enhancement is more easily observed with the cells of non-infected animals or during the early phase of infection or reinfection. The mitogen-induced increase in IgE synthesis did not exceed the values obtained during infection or reinfection. [ABSTRACT FROM AUTHOR]

Hybridomas secreting monoclonal antibodies to Nippostrongylus brasiliensis antigens were generated by hybridization of IR983F myeloma cells with spleen cells from Lou/M/Wol rats infected with living third-stage larvae. Antibodies specific either for larval or worm antigens were identified by enzyme-linked immunosorbent assays with Nippostronylus brasiliensis fragments, homogenates and secretions as antigens. The results demonstrate that all antibodies which recognized larval antigens (38 antibodies) also reacted with worm surfaces. Ten antibodies were specific only for worm antigens. Ten antibodies reacted with worm homogenate, three antibodies recognized components of worm secretion and 17 antibodies combined with acetylcholinesterase. The epitope specificity was investigated by the capacity of various glycosides, aminoacids, N-acetylneuraminic acid and phosphorylcholine to inhibit the binding to worm fragments. The analysis revealed that α-methylglucoside, α-methylmannoside, N-acetylglucosamine, N-acetylgalactosamine, fucose and the amino acids leucine, phenylalanine, tyrosine, serine, tryptophan did not combine with the antigen-binding sites of the antibodies. Proline, arginine and histidine, however, displayed inhibitory effects. With N-acetylneuraminic acid as inhibitor three groups of antibodies could be discriminated. At a concentration of 10-20 mM, phosphorylcholine was a potent inhibitor for all antibodies. [ABSTRACT FROM AUTHOR]

The frontal secretion of Nasutitermes princeps consists of 89% diterpenes and 11% monoterpenes. In the samples studied, (+)-α-pinene, whose optical purity reaches 99.5%, accounts for more than 80% of the monoterpenic content. [ABSTRACT FROM AUTHOR]

Antigenic proteins were characterized by the immunoblotting technique with sera from rats and mice after infection as well as hyperimmune sera. The immune response of infected animals was mainly directed toward five proteins of adult worms (190, 118, 110, 98, and 52 kDa) and four proteins of the third larval stage (L3; 92, 78, 58, and 24 kDa). The immunoblots indicated that stage-specific proteins of the homogeneates were recognized. Three stage-specific proteins of L3 larvae (150, 135, and 125 kDa) and three proteins typical to the adult worm (100, 82, and 67 kDa) were identified. The majority of the worm proteins elicited an IgG response. IgE synthesis was induced by living and dead parasites and was directed towards four proteins (190, 150, 125, and 98 kDa). Three proteins additionally induced an IgG or IgM antibody response. The immune response as shown by the immunoblotting technique seems to be directed towards (1) antigens that are present for the duration of an infection and (2) stage-specific antigens that are expressed for only a short time during the life cycle of the parasite. [ABSTRACT FROM AUTHOR]

The effect of serum factors on Ig synthesis (IgE, IgG) in vitro was analyzed. Spleen and mesenteric lymph node cells were obtained from Nippostrongylus brasiliensis-infected and non-infected mice. Sera and ammonium sulphate precipitated serum fractions from mice of different genetic origin (Balb/c - H-2, A.CA - H-2, B10.G - H-2) suppressed in vitro IgE synthesis whereas a pronounced enhancement of IgG antibody synthesis was obtained in several experiments. Our results obtained with sera from both high and low IgE responder strains demonstrated that no strain specificity exists as to the inhibitory efficacy of mouse sera for total IgE synthesis in vitro. The suppressive activity of the mouse sera was concentrated in a fraction precipitated with 20%-50% saturated ammonium sulphate. Amicon XM50 ultrafiltration suggested that this fraction had an apparent molecular weight >50,000 daltons. Suppressive activity was removed by immunoadsorption of the 20-50% fraction with anti-IgE Sepharose. After exogenous addition of monoclonal IgE to an inactive fraction in vitro neither the fraction enriched in IgE nor monoclonal IgE alone were able to suppress IgE synthesis in the culture. Our results suggest that one or more serum factors in the presence of IgE are responsible for the suppression of total IgE synthesis in vitro. [ABSTRACT FROM AUTHOR]

( S)-;(+)-4-Methyl-3-heptanone is the principal component in the secretion from the mandibular glands of unmated and mated males and females of Atta sexdens rubropilosa. In mated and unmated females, it is essentially the only component in the glandular secretion. In unmated males up to 50% of the secretion is a mixture of (3 S, 4 S)- and (3 R, 4 S)-4-methyl-3-heptanol. After mating, the amount of alcohol in the males decreases markedly. [ABSTRACT FROM AUTHOR]