Bacterial community changes in copper and PEX drinking water pipeline biofilms under extra disinfection and magnetic water treatment.

AIMS: To study the stability of biofilms and water quality in pilot scale drinking water copper and PEX pipes in changing conditions (extra disinfection, magnetic water treatment, MWT). METHODS AND RESULTS: Next-generation sequencing (NGS) of 16S ribosomal RNA genes (rDNA) to describe total bacterial community and ribosomal RNA (rRNA) to describe active bacterial members in addition to traditional microbiological methods were applied. Biofilms from control copper and PEX pipes shared same most abundant bacteria (Methylobacterium spp., Sphingomonas spp., Zymomonas spp.) and average species diversities (Shannon 3·8-4·2) in rDNA and rRNA libraries, whereas few of the taxa differed by their abundance such as lower total Mycobacterium spp. occurrence in copper (<0·02%) to PEX (<0·2%) pipes. Extra disinfection (total chlorine increase from c. 0·5 to 1 mg l-1 ) affected total and active population in biofilms seen as decrease in many bacterial species and diversity (Shannon 2·7, P < 0·01, rRNA) and increase in Sphingomonas spp. as compared to control samples. Furthermore, extra-disinfected copper and PEX samples formed separate clusters in unweighted non-metric multidimensional scaling plot (rRNA) similarly to MWT-treated biofilms of copper (but not PEX) pipes that instead showed higher species diversity (Shannon 4·8, P < 0·05 interaction). CONCLUSIONS: Minor chlorine dose addition increased selection pressure and many species were sensitive to chlorination. Pipe material seemed to affect mycobacteria occurrence, and bacterial communities with MWT in copper but not in PEX pipes. SIGNIFICANCE AND IMPACT OF THE STUDY: This study using rRNA showed that chlorination affects especially active fraction of bacterial communities. Copper and PEX differed by the occurrence of some bacterial members despite similar community profiles.

Copper as an antibacterial material in different facilities.

The present study was performed in real life settings in different facilities (hospital, kindergarten, retirement home, office building) with copper and copper alloy touch surface products (floor drain lids, toilet flush buttons, door handles, light switches, closet touch surfaces, corridor hand rails, front door handles and toilet support rails) in parallel to reference products. Pure copper surfaces supported lower total bacterial counts (16 ± 45 vs 105 ± 430 CFU cm-2 , n = 214, P < 0·001) and a lower occurrence of Staphylococcus aureus (2·6 vs 14%, n = 157, P < 0·01) and Gram-negatives (21 vs 34%, n = 214, P < 0·05) respectively than did reference surfaces, whereas the occurrence of enterococci (15%, n = 214, P > 0·05) was similar. The studied products could be assigned to three categories according to their bacterial loads as follows (P < 0·001): floor drain lids (300 ± 730 CFU cm-2 , n = 32), small area touch surfaces (8·0 ± 7·1 to 62 ± 160 CFU cm-2 , n = 90) and large area touch surfaces (1·1 ± 1·1 to 1·7 ± 2·4 CFU cm-2 , n = 92). In conclusion, copper touch surface products can function as antibacterial materials to reduce the bacterial load, especially on frequently touched small surfaces. SIGNIFICANCE AND IMPACT OF THE STUDY: The efficiency of copper as an antimicrobial material has been noted in laboratory studies and in the hospital environment. The present study further shows that copper exerted an antibacterial effect in different facilities, i.e. in a hospital, a kindergarten, an office building and in a retirement home for the elderly. The study suggests that copper has potential use as an antibacterial material and therefore might serve as a means to lower the incidence of transmission of infectious agents from inanimate surfaces in different facilities, with everyday functions.

Interleukin-6, interleukin-1 receptor antagonist and interleukin-1beta production in patients with focal epilepsy: A video-EEG study.

UNLABELLED: Experimental and clinical studies have shown that prolonged seizures result in increased cytokine production in the central nervous system. The purpose of this study was to examine plasma concentrations of interleukin-6 (IL-6), interleukin-1 receptor antagonist (IL-1Ra), and interleukin-1 beta (IL-1beta) in 20 patients with epilepsy undergoing a video-EEG study. Plasma samples were obtained at the onset of the recordings and 3, 6, 12 and 24 h after the index seizure. Localization of the seizure focus and classification of epilepsy was based on concordant electroclinical findings in the video-EEG study, and on MRI examination. Patients were divided into two groups: temporal lobe epilepsy (TLE) (n=11), and extratemporal lobe epilepsy (XLE) (n=9). RESULTS: Only the TLE group showed significant increase in plasma levels of IL-6 peaking at 6 h postictally. Postictal plasma levels of IL-1RA and IL-1beta did not significantly differ from baseline levels in either of the patient groups. IL-1RA showed a decreasing trend (p>0.059) in TLE patients during 12 to 24 postictal hours. CONCLUSIONS: This study further supports the role of focal seizures in regulation of cytokine responses.

Increased plasma levels of cytokines after seizures in localization-related epilepsy.

OBJECTIVES: Experimental studies suggest increased cerebral production of inflammatory cytokines after prolonged seizures. Whether a single non-prolonged seizure in human patients is associated with activation of cytokine network is still unknown. MATERIALS AND METHODS: We studied the levels of interleukin-1beta (IL-1beta), interleukin-1 receptor antagonist (IL-1ra), interlukin-6 (IL-6) and soluble IL-6 receptors (sIL-6R and Gp130) in plasma after single seizures during video-EEG recordings in patients with chronic localization-related epilepsy. RESULTS: The levels of IL-1ra and IL-6 were increased after seizures, whereas IL-1beta and IL-6 cytokine receptors remained unchanged. CONCLUSIONS: These results show that only single seizures cause activation of cytokine cascade and associated inflammatory signals. In the case of recurrent seizures, these signals may result in structural changes in the nervous tissue, which are generally associated with drug refractory epilepsy.

The asthma programme of Finland: an evaluation survey in primary health care.

OBJECTIVE: To evaluate the basic structures and processes of asthma care 6 years after the launch of the Finnish Asthma Programme. The evaluation will serve as the baseline for the implementation of the evidence-based guidelines for asthma published in 2000. DESIGN: A descriptive type-2 evaluation (managerial monitoring of a policy implementation), based on operationalised statements of the Asthma Programme. RESULTS: A co-ordinating doctor for asthma, usually a general practitioner (GP), was interviewed in 248 (91%) health centres; 83% of the health centres have at least one GP nominated as the local asthma co-ordinator and 94% have a nurse. Asthma education for the professionals had been organised in 71% of the health centres in the previous 2 years. First-line treatment consists of an inhaled corticosteroid. Guided self-management is used in 98% of the health centres, but its components were not clear to the doctors. CONCLUSION: The basic structure of equipment and organisation for the diagnosis and treatment of asthma has been set up in the primary health care services.

Switching supramolecular polymeric materials with multiple length scales

It was demonstrated that polymeric supramolecular nanostructures with several length scales allow straightforward tailoring of hierarchical order-disorder and order-order transitions and the concurrent switching of functional properties. Poly(4-vinyl pyridine) (P4VP) was stoichiometrically protonated with methane sulfonic acid (MSA) to form P4VP(MSA)1.0, which was then hydrogen-bonded to pentadecylphenol. Microphase separation, re-entrant closed-loop macrophase separation, and high-temperature macrophase separation were observed. When MSA and pentadecylphenol were complexed to the P4VP block of a microphase-separated diblock copolymer poly[styrene-block-(4-vinyl pyridine)], self-organized structures-in-structures were obtained whose hierarchical phase transitions can be controlled systematically. This microstructural control on two different length scales (in the present case, at 48 and 350 angstroms) was then used to introduce temperature-dependent transitions in electrical conductivity.

Transformation of hydroxyapatite to fluorapatite by irradiation with high-energy CO2 laser.

High-energy laser irradiation has been shown to cause crystalline transformations in apatites, which may lead to the formation of tricalcium phosphates with a resulting decrease in acid resistance. Depending on the nature and energy density of laser irradiation used, however, an increase of acid resistance of dental enamel has also been reported after laser irradiation. The aim of the present study was to investigate the phase transformation of hydroxyapatite (HA) to fluorapatite (FA) in a model system that incorporates sodium fluoride (NaF) into apatite structure by using laser irradiation. A CO2 laser was used at energy densities ranging from 21 to 500 J/cm2. Synthetic HA mixed with NaF (10:1) was the target of laser irradiation. The crystalline structures were then investigated using X-ray diffraction analysis. The results showed that a phase transformation of HA to FA could be realized, and that the threshold energy density needed was 38 J/cm2. Not only is the finding crystallographically important, but it also opens new perspectives for future research regarding the development of laser technology for clinical purposes.

Healing of rat mouth mucosa after irradiation with CO2, Nd:YAG, and CO2-Nd:YAG combination lasers.

The healing process of wounds made by a combination laser was studied in 90 rats. The laser system enabled both separate and combined use of CO2 and Nd:YAG laser irradiations. The laser wounds and the control excision wounds made by alligator forceps appeared on both sides of the tongue. Specimens from the wound sites were taken immediately, 6 h, and 1, 2, 4, 7, 11, 21, 28, and 42 days after surgery. The wound-healing process was studied by macroscopic evaluation before preparing the specimens for light microscopy. Some differences were noted in the wound-healing process among the three groups into which the experimental animals were divided. Tissue coagulation damage was most extensive in the Nd:YAG laser sites, where it was observed in its full extent 4 days after surgery. Epithelial cells were seen to begin to proliferate in all the wounds 6 h after surgery. Re-epithelialization was completed by between 7 (CO2) and 21 days (Nd:YAG) at all the wound sites. The inflammatory cell infiltration was more prominent in the Nd:YAG and the CO2-Nd:YAG combination laser wounds than in the CO2 and excision wounds during healing. Tissue regeneration occurred faster with less contraction in the combination CO2-Nd:YAG wounds than in Nd:YAG wounds. The best macroscopic healing result was seen in the CO2 wound sites. The combination laser was effective both at cutting and at coagulating tissue. Combining the CO2 and Nd:YAG laser irradiation into one beam resulted in a greater incision depth than what could have been expected from using the two lasers separately.

Paraprofessional staff: a review and report on current duty assignment in academic health sciences libraries in North America.

This paper reviews paraprofessional employment in libraries and examines the trend toward assigning increasingly complex duties to academic library paraprofessionals. During the spring of 1989, directors of academic health sciences libraries in the United States and Canada were surveyed to determine the duties assigned to paraprofessionals. The results show that paraprofessionals are assigned a wide range of duties, including supervising functional areas, such as circulation and interlibrary loan, and some tasks often considered professional, such as original cataloging and in-depth reference work. The findings illustrate the importance of the paraprofessional to librarianship.

Effects of carbon dioxide, Nd:YAG and carbon dioxide-Nd:YAG combination lasers at high energy densities on synthetic hydroxyaptite.

The aim of this study was to determine the crystalline structure and chemical alterations of synthetic hydroxyapatite after irradiation with either CO2, Nd:YAG or CO2-Nd:YAG combination lasers at high energy densities of 500-3,230 J.cm2. Further, dissolution kinetics of the lased material were analysed and compared with those of unlased apatite. Electron microscopy showed that the lased material consisted of two kinds of crystals. From the micrographs their diameters varied from 600 to 1,200 A and from 3,000 to 6,000 A, respectively. The larger crystals showed 6.9-Angström periodic lattice fringes in the transmission electron microscope. alpha-Tricalcium phosphate (TCP) was identified by X-ray diffraction. Selective-area electron diffraction identified the large crystals to consist of tricalcium phosphate while the smaller crystals were probably hydroxyapatite. Assays of dissolution kinetics showed that at these high energy densities lased material dissolved more rapidly than unlased synthetic hydroxyapatite due to the higher solubility of TCP.

Irradiation of human dental tissues with CO2-, Nd:YAG-, and CO2-Nd:YAG combination laser.

Extracted third molars were used to study the effect of Nd:YAG laser irradiation combined with CO2 laser beam on dental hard tissues. The specimens were studied with SEM after lasing and the size of the impact areas and beam penetration into enamel and dentin were planimetrically analyzed. High-energy CO2 laser (e.g. 10 s irradiation with 10 W output energy) penetrated all enamel and dentin. The simultaneous addition of Nd:YAG irradiation to the CO2 beam was found to increase the effect of CO2 laser, while Nd:YAG irradiation alone, used with equivalent energy densities, did not cause any effect on enamel surface. Thus, Nd:YAG laser was found to potentiate statistically significantly the effect of CO2 irradiation, but the morphologic alterations on dental hard tissues, such as crater formation at the beam focus site, appeared to be due to CO2 irradiation alone.

Remodelling by asymmetrical epiphysial growth. An experimental study in dogs.

Spontaneous correction of deformity is produced by bone remodelling during the period of growth. The purpose of this experimental study was to find out in which phase and to what extent asymmetrical epiphysial growth participated in the correction of an experimentally produced deformity. Transverse wedge osteotomy was performed in the legs of twenty growing mongrel dogs, the fragments being fixed with bent AO-plates. From radiographs taken at intervals of two weeks the epiphysial and axial angles were measured. Nine dogs were given tetracycline ten to twenty days before death and the cut surfaces were photographed in reflected ultra-violet light. It was found that epiphysial growth played an important role in the remodelling process. This factor accounted for roughly half of the total correction and averaged 12-5 degrees during the observation time of 160 days. The greatest correction occurred during the first weeks. Correction of the epiphysial angle took place with acceleration of growth.