Construction ofClostridium butyricum hybrid plasmids and transfer toBacillus subtilis

Summary Small plasmids were isolated from type strains ofClostridium butyricum. Strain NCIB 7423 carries one plasmid (pCBU1) of 6.4 kb, whereas strain NCTC 7423 carries two unrelated plasmids of 6.3 kb (pCBU2) and 8.4 kb (pCBU3). Cleavage sites for 18 restriction endonucleases have been mapped on these plasmids and detailed physical maps are presented. For the purpose of developing vector plasmids for gene cloning in saccharolytic clostridia these crypticC. butyricum plasmids were joined to a selectable marker that will likely be expressed in clostridia. This was achieved by cloning the clostridial plasmids into theE. coli vector pBR322 carrying the chloramphenicol acetyltransferase (CAT) gene from theStaphylococcus aureus plasmid pC194. The recombinant plasmids were tested for their ability to confer chloramphenicol resistance toBacillus subtilis. Hybrid plasmids (pHL105, pHL1051) derived from pCBU2 were identified, which are capable of replication and expression of theS. aureus drug resistance marker in bothE. coli andB. subtilis. No structural instability was detected upon retransformation of pHL105 fromB. subtilis intoE. coli. The recombinant plasmids might thus be useful as shuttle vectors for the gene transfer betweenE. coli and a wide range of bacilli and clostridia.     

Adaption of subjects in field studies of informatory working conditions (author's transl)]

Processes of adaption in measurements of performance - cycle-times, variance of cycle-times, informatory component of time and errors - and of physiological strain - electromyograms of musculus extensor digitorum and musculus rhomboideus, horizontal and vertical electrooculogram, heart rate and heart rate variability - are presented and described in type and frequency. Simultaneous reactions and successive reactions of measured variables in dependance of shift-time and of days are described. They are classified according to the causes "exercise" and "emotional habituation" and discussed in a model "experimenter - experimental situation".     

Karyometric observations of WISH cell cultures irradiated with 3 GHz microwaves.

WISH cell cultures 24 hours after passage were irradiated with 3 GHz microwaves (10 cm) at far field conditions in free space (anechoic chamber) for 30 minutes, at field power density 5 or 20 mW/cm2. Within 1,24 and 48 hours of the exposure to microwave fields the volumes of nuclei and nucleoli were measured with the use of a micrometer, and logvolumes and nucleo-nucleolar ratios were calculated. Under the applied irradiation conditions the culture medium temperature did not exceed 37 degrees C. In cultures irradiated at field power density 20 mW/cm2 increased number of cells with small nuclei and enlarged nucleoli was noted within 1 hour of the exposure. Within 24 and 48 hours after irradiation the nucleolar volume showed a slight decrease, whereas the nuclear volume increased. In cultures irradiated at field power density 5 mW/cm2 increased numbers of cells with enlarged nuclei and nucleoli were found. Analysis of the distribution curves of nuclear and nucleolar volumes suggests that non-thermal power densities of microwaves stimulate the metabolism of cell cultures. However, at higher power densities (20 mW/cm2) the stimulation phase is preceded by a period of reduced viability of cell cultures.     

Role of ultrasonography in diagnosing early rheumatoid arthritis and remission of rheumatoid arthritis - a systematic review of the literature

Introduction

Ultrasonography (US) might have an added value to clinical examination in diagnosing early rheumatoid arthritis (RA) and assessing remission of RA. We aimed to clarify the added value of US in RA in these situations performing a systematic review.

Methods

A systematic literature search was performed for RA, US, diagnosis and remission. Methodological quality was assessed; the wide variability in the design of studies prohibited pooling of results.

Results

Six papers on the added value of US diagnosing early RA were found, in which at least bilateral metacarpophalangeal (MCP), wrists and metatarsophalangeal (MTP) joints were scanned. Compared to clinical examination, US was superior with regard to detecting synovitis and predicting progression to persistent arthritis or RA. Eleven papers on assessing remission were identified, in which at least the wrist and the MCP joints of the dominant hand were scanned. Often US detected inflammation in patients clinically in remission, irrespective of the remission criteria used. Power Doppler signs of synovitis predicted X-ray progression and future flare in patients clinically in remission.

Conclusions

US appears to have added value to clinical examination for diagnosing of RA when scanning at least MCP, wrist and MTP joints, and, when evaluating remission of RA, scanning at least wrist and MCP joints of the dominant hand. For both purposes primarily power Doppler US might be used since its results are less equivocal than those of greyscale US.     

Antibmicrobial susceptibility of Serratia marcescens isolated from hospitalized patients in 2003 - 2005

500 strains of Serratia marcescens isolated in 2003-2005 were examined for drug susceptibility. By using several phenotypic methods it was shown that 67.6% of these strains produced ESBLs. Strains ESBL(-) and ESBL(+) were compared, paying special attention to their susceptibility to various antibiotics. It was revealed that strains ESBL(+) were much more resistant to majority of the investigated drugs. The biggest differences were in the case of amikacin and gentamicin, sensitive about 50% of ESBL(-) and 10% of ESBL(+), ciprofloxacin, sensitive 42% of ESBL(-) and 6.3% of ESBL(+) and trimethoprim/ sulphametoxazole, sensitive 45.8% of ESBL(-) and 9.4% of ESBL(+). Strains ESBL(-) retained a high susceptibility to ceftazidime (68.9%) and cefepime (71%). All strains ESBL(-) as well as ESBL(+) were susceptible to imipenem and meropenem. 78.9% of ESBL(-) and 67.3% of investigated ESBL(+) were susceptible to piperacillin/ tazobactam.     

Survey of susceptibility of clinical Clostridium diffiicile strains isolated from patients hospitalised in different departments of paediatric hospital to antimicrobial agents

This study was performed to determine the susceptibility of 50 C. difficile strains isolated from faecal samples of children suspected to antibiotic associated diarrhea (AAD) to antimicrobial agents: metronidazole, vancomycin, erythromycin, clindamycin, ciprofloxacin, moxifloksacin, gatifloksacin and imipenem. The all C. difficile strains were sensitived to metronidazole and vancomycin. Twenty six per cent of strains were resistant to erythromycin and clindamycin (MLS(B) type resistance). Resitance to ciprofloxacin, moxifloxacin, gatifloxacin and imipenem was detected in 98%, 8%, 8% and 30% of C. difficile strains, respectively.     

Introgression mapping of genes for winter hardiness and frost tolerance transferred from Festuca arundinacea into Lolium multiflorum

Genes for winter hardiness and frost tolerance were introgressed from Festuca arundinacea into winter-sensitive Lolium multiflorum. Two partly fertile, pentaploid (2n = 5x = 35) F(1) hybrids F. arundinacea (2n = 6x = 42) x L. multiflorum (2n = 4x = 28) were generated and backcrossed twice onto L. multiflorum (2x). The backcross 1 (BC(1)) and backcross 2 (BC(2)) plants were preselected for high vigor and good fertility, and subsequently, a total of 83 BC(2) plants were selected for winter hardiness after 2 Polish winters and by simulated freezing tests. Genomic in situ hybridization (GISH) was performed on 6 winter-hardy plants selected after the first winter and shown to be significantly (P < 0.05) more frost tolerant than the L. multiflorum control. Among the analyzed BC(2) winter survivors, only diploid (2n = 2x = 14) plants were found. Five plants carried 13 intact L. multiflorum chromosomes and 1 L. multiflorum chromosome with a single introgressed F. arundinacea terminal chromosome segment. The sixth BC(2) winter survivor appeared to be Lolium without any Festuca introgression capable of detection by GISH. A combined GISH and fluorescence in situ hybridization analysis with rDNA probes of the most winter-hardy (after 2 winters) and frost-tolerant BC(2) plant revealed the location of an F. arundinacea introgression on the nonsatellite arm of L. multiflorum chromosome 2, the same chromosome location reported previously as a site for frost tolerance genes in the diploid and winter-hardy species Festuca pratensis.     

Recording Large-scale Neuronal Ensembles with Silicon Probes in the Anesthetized Rat

Large scale electrophysiological recordings from neuronal ensembles offer the opportunity to investigate how the brain orchestrates the wide variety of behaviors from the spiking activity of its neurons. One of the most effective methods to monitor spiking activity from a large number of neurons in multiple local neuronal circuits simultaneously is by using silicon electrode arrays^1-3.Action potentials produce large transmembrane voltage changes in the vicinity of cell somata. These output signals can be measured by placing a conductor in close proximity of a neuron. If there are many active (spiking) neurons in the vicinity of the tip, the electrode records combined signal from all of them, where contribution of a single neuron is weighted by its ''electrical distance''. Silicon probes are ideal recording electrodes to monitor multiple neurons because of a large number of recording sites (+64) and a small volume. Furthermore, multiple sites can be arranged over a distance of millimeters, thus allowing for the simultaneous recordings of neuronal activity in the various cortical layers or in multiple cortical columns (Fig. 1). Importantly, the geometrically precise distribution of the recording sites also allows for the determination of the spatial relationship of the isolated single neurons⁴. Here, we describe an acute, large-scale neuronal recording from the left and right forelimb somatosensory cortex simultaneously in an anesthetized rat with silicon probes (Fig. 2).