Effects of hand disinfection with alcohol hand rub, ozonized water, or soap and water: time for reconsideration?

The effect of alcohol hand rub was tested in eradicating Escherichia coli, and compared with hand wash using ozonized tap water or soap and water. Alcohol eradicated all bacteria in 10 out of 35 participants, but with an average (SD) of 2330 (4227) cfu/mL left after disinfection, whereas ozonized water removed all bacteria in 10 out of 55 participants, with an average of only 538 (801) cfu/mL left (P = 0.045). Soap washing was the most effective with total removal of bacteria in six out of 20 participants, with an average of 98 (139) cfu/mL (P = 0.048 and 0.018 versus ozonized water and alcohol, respectively).

Ozonized water as an alternative to alcohol-based hand disinfection.

BACKGROUND: Hand hygiene plays a vital role in the prevention of transmission of micro-organisms. Ozone (O3) is a highly reactive gas with a broad spectrum of antimicrobial effects on bacteria, viruses, and protozoa. It can easily be produced locally in small generators, and dissolved in tap water, and quickly transmits into ordinary O2 in the surrounding air. AIM: To compare ozonized tap water and alcohol rub in decontamination of bacterially contaminated hands. METHODS: A cross-over study among 30 nursing students. Hands were artificially contaminated with Escherichia coli (ATCC 25922), then sanitized with ozonized tap water (0.8 or 4 ppm) or 3 mL standard alcohol-based rub (Antibac 85%). The transient microbes from fingers were cultivated and colony-forming units (cfu)/mL were counted. The test procedure was modified from European Standard EN 1500:2013. FINDINGS: All contaminated hands before disinfection showed cfu >30,000/mL. The mean (SD) bacterial counts in (cfu/mL) on both hands combined were 1017 (1391) after using ozonized water, and 2337 (4664) after alcohol hand disinfection. The median (range) values were 500 (0-6700) and 250 (0-16,000) respectively (non-significant difference). Twenty per cent of participants reported adverse skin effects (burning/dryness) from alcohol disinfection compared with no adverse sensations with ozone. CONCLUSION: Ozonized tap water is an effective decontaminant of E. coli, and it could be an alternative to traditional alcohol-fluid hand disinfectants both in healthcare institutions and public places. Ozonized water may be especially valuable for individuals with skin problems.

Dechlorination of the dietary nona-chlorinated toxaphene congeners 62 and 50 into the octa-chlorinated toxaphene congeners 44 and 40 in zebrafish (Danio rerio) and Atlantic salmon (Salmo salar).

The relative feed-to-fish accumulation and possible biotransformation of the nona-chlorinated toxaphene congeners currently included in EU-legislation (CHB-50 and -62) and the octa-chlorinated congeners recommended by the European Food Safety Authority to be included in future surveillance of fish samples (CHB-40, 41, and 44) were investigated in the present study. Model fish Danio rerio were fed either (a) diets spiked with a combination as well as the pure individual toxaphene congeners CHB-50 or 62 or (b) diets spiked with the combination of CHB ∑50+62 and/or CHB ∑40+41+44. In addition, seawater adapted Atlantic salmon smolts were fed technical toxaphene enriched feeds for 62 days. Zebrafish fed a diet containing CHB-50 and CHB-62 accumulated newly formed CHB-40&41 and CHB-44, respectively. The biomagnifications factors (BMF) of the toxaphene congeners in Atlantic salmon muscle from the feeds spiked with technical toxaphene were significantly correlated with their relative lipophilicity (expressed as logK(ow)). An exception was CHB-44 which had a higher BMF than could be expected from its specific logK(ow), reflecting that CHB-44 is a metabolite formed under dietary exposure to CHB-62. This paper reports the in vivo dechlorination of nona-chlorinated toxaphene congeners into octa-chlorinated congeners in feeding trials with a model fish (zebrafish) and an oily food fish (Atlantic salmon).

Monocyte exposure to Saccharomyces cerevisiae cell wall mannan and decreased TNF-alpha production in mild asthma: a role for mannan-binding lectin?

A correlation between fungal exposure and aggravation of inflammatory symptoms in asthmatic individuals is well documented in the literature. However, the molecular mediators responsible for clinical symptoms due to fungal exposure in individuals with asthma are still not known. The fungal cell wall polysaccharide mannan stimulates production of pro-inflammatory cytokines such as tumour necrosis factor (TNF)-alpha in monocytes. Recently, a role for the plasma protein mannan-binding lectin (MBL) has been proposed in individuals with severe asthmatic disease, although little is known about its role in those with mild and untreated asthma. MBL has been reported to modulate inflammatory cytokine production, but the mechanisms are not known. We conducted a pilot study and found that the cell wall mannan preparation used stimulated lower TNF-alpha production by monocytes from asthmatic subjects compared with that from healthy subjects in the presence of autologous plasma. Lipopolysaccharide-induced TNF-alpha production was not significantly different between the groups. Further, plasma MBL levels in individuals with mild asthma were slightly increased compared with those in normal subjects, although the difference was not statistically significant. We speculate that reduced TNF-alpha production in monocytes from asthmatic subjects after fungal cell wall mannan stimulation could partly be influenced by plasma components such as MBL.

An overview and analysis of theories employed in telemedicine studies. A field in search of an identity.

OBJECTIVES: This study asks: What theories are employed in telemedicine studies? How might they be categorized in ways that help distinguish the knowledge base of telemedicine? METHODS: Theories in use were identified from a database of telemedicine-related publications between 1990 and 2005. Eighty-three (5% of 1615) articles referred to a theoretical concept. Grounded Theory procedures were used to analyze and categorize theories, while descriptive statistics were used for supplementary information. RESULTS: The proportion of studies with theory was 3% in 1999 and 7% in 2005. The 83 articles were dispersed among 48 of the in total 795 different journals in the original sample. Identified theories were grouped into two main categories; 'shared' (used in two or more studies) and 'lone ranger'. All of the shared theories are social science theories employed without notable adjustments to any uniquely defining features of telemedicine; diffusion, technology acceptance, health behavior, science and technology studies (STS), and economics. Theoretical concepts within the lone ranger category may well address unique features of telemedicine, but have yet to attract the attention of colleagues. CONCLUSION: The theories identified as 'shared' play an important role, but are inadequate in illuminating any unique features of telemedicine. The future of telemedicine as a field will need to identify its underlying theoretical components. Frameworks employed in the field of evaluation may aid in identifying the types of theories worth articulating in telemedicine.

Mycotoxin-induced depletion of intracellular glutathione and altered cytokine production in the human alveolar epithelial cell line A549.

Mould exposure has been associated with asthma and other inflammatory airway conditions. However, cellular effects of inhaled mould components are not well understood. We hypothesised that host defence mechanisms, such as production of cytokines (TGFbeta1, IL-6 and IL-8) and the intracellular antioxidant glutathione (GSH), could be adversely affected by different concentrations of mycotoxins. We studied the effects of citrinin and gliotoxin on lipopolysaccharide (LPS)-stimulated alveolar epithelial cells (A549). Cytokines in cell culture supernatants were analysed by ELISA and levels of GSH were measured by colorimetric (absorbance) determination. We found that GSH decreased in a dose- and time-dependent manner when cells were exposed to citrinin in particular. TGFbeta1 was moderately reduced at low mycotoxin concentrations but elevated at higher sub-toxic concentrations. A tendency for an inverse relationship between TGFbeta1 and GSH levels was observed. IL-6 and IL-8 were not significantly reduced at non-toxic mycotoxin concentrations. Thus, reduced epithelial GSH and TGFbeta1 levels combined with elevated IL-6 and IL-8 levels may result in increased pro-inflammatory activity during mycotoxin exposure. We suggest that this mechanism can contribute to inflammation in mould exposure.

The mycotoxins citrinin and gliotoxin differentially affect production of the pro-inflammatory cytokines tumour necrosis factor-alpha and interleukin-6, and the anti-inflammatory cytokine interleukin-10.

BACKGROUND: Microbial growth is considered one of the major causes of indoor air problems. Moulds have been associated with asthma, allergy and a wide range of diffuse indoor air-related symptoms. However, mechanisms of the adverse health effects are not well understood. OBJECTIVE: We hypothesized that the mycotoxins citrinin and gliotoxin could cause an imbalance between the secretion of the pro-inflammatory cytokines TNF-alpha and IL-6 and the anti-inflammatory cytokine IL-10. METHODS: We investigated the influence of citrinin and gliotoxin on the human monocytic cell line Mono-Mac-6 (MM6) with and without lipopolysaccharide -stimulation. The levels of IL-10, IL-6 and TNF-alpha were analysed in cell culture supernatants by ELISA. Cell viability and cell apoptosis were measured by flow cytometry. RESULTS: The strongest inhibition of cytokine secretion was found for IL-10. IL-6 levels were found to decrease in a dose-dependent manner along with reduced cell viability. TNF-alpha levels increased with low gliotoxin exposure (less than 100 ng/mL), but decreased significantly at 375 ng/mL and higher along with increased cell apoptosis and reduced cell viability. TNF-alpha levels were not reduced by citrinin exposure. CONCLUSION: We observed a cytokine imbalance with a more pronounced reduction of IL-10 concentrations compared with those of TNF-alpha and IL-6. We suggest that low exposure doses of citrinin and gliotoxin (corresponding to less than 100 ng/mL gliotoxin and less than 10 mug/mL citrinin) may inhibit IL-10 and lead to increased risk of an inflammatory response with relative overproduction of TNF-alpha and IL-6. The findings and their clinical implications must be verified by human studies. However, we speculate that the observed biological effects may be of importance as they may partly explain the occurrence of diffuse general indoor air-related symptoms as well as the worsening of asthmatic inflammatory reactions experienced in mouldy environments.

Heterodimerization of the epidermal-growth-factor (EGF) receptor and ErbB2 and the affinity of EGF binding are regulated by different mechanisms.

When clathrin-dependent endocytosis is inhibited in HeLa cells by overexpression of a K44A (Lys(44)-->Ala) mutant of the GTPase dynamin, high-affinity binding of epidermal growth factor (EGF) to the EGF receptor (EGFR) is disrupted [Ringerike, Stang, Johannessen, Sandnes, Levy and Madshus (1998) J. Biol. Chem. 273, 16639-16642]. We now report that the effect of [K44A]dynamin on EGF binding was counteracted by incubation with the non-specific kinase inhibitor staurosporine (SSP), implying that a protein kinase is responsible for disrupted high-affinity binding of EGF upon overexpression of [K44A]dynamin. The effect of [K44A]dynamin on EGF binding was not due to altered phosphorylation of the EGFR, suggesting that the activated kinase is responsible for phosphorylation of a substrate other than EGFR. The number of EGFR molecules was increased in cells overexpressing [K44A]dynamin, while the number of proto-oncoprotein ErbB2 molecules was unaltered. EGF-induced receptor dimerization was not influenced by overexpression of [K44A]dynamin. ErbB2-EGFR heterodimer formation was found to be ligand-independent, and the number of heterodimers was not altered by overexpression of [K44A]dynamin. Neither SSP nor the phorbol ester PMA, which disrupts high-affinity EGF-EGFR interaction, had any effect on the EGFR homo- or hetero-dimerization. Furthermore, the EGF-induced tyrosine phosphorylation of ErbB2 was not affected by overexpression of [K44A]dynamin, implying that EGFR-ErbB2 dimers were fully functional. Our results strongly suggest that high-affinity binding of EGF and EGFR-ErbB2 heterodimerization are regulated by different mechanisms.

Epidermal growth factor receptor efficiently activates mitogen-activated protein kinase in HeLa cells and Hep2 cells conditionally defective in clathrin-dependent endocytosis.

Epidermal growth factor (EGF)-induced signaling was investigated in cells conditionally defective in clathrin-dependent endocytosis by overexpression of K44A dynamin in HeLa cells and potassium depletion in Hep2 cells. Overexpression of mutant dynamin disrupts high-affinity EGF-EGF receptor (EGFR) interaction (T. Ringerike, E. Stang, L. E. Johannessen, D. Sandnes, F. O. Levy, and I. H. Madshus, 1998, J. Biol. Chem. 273, 16639-16642). However, the EGFR substrates Shc and c-Cbl were as efficiently tyrosine phosphorylated in endocytosis-deficient HeLa cells exhibiting only low-affinity EGFRs as in HeLa cells with intact endocytosis and with both high- and low-affinity EGFRs. Both Raf and mitogen-activated protein kinase (MAPK) were activated to the same extent and with the same kinetics. HeLa cells distributed equally in the cell cycle regardless of EGFR internalization. Upon potassium depletion of Hep2 cells, EGF-induced EGFR endocytosis was inhibited. However, the EGFR and MAPK were efficiently activated by EGF in both the absence and the presence of clathrin-dependent endocytosis. The EGFR was weakly tyrosine phosphorylated by potassium depletion even in the absence of EGF, and this activation resulted in detectable activation of MAPK. Our results demonstrate that internalization of EGFR by clathrin-dependent endocytosis is not required for activation of MAPK.

Polyubiquitination of the epidermal growth factor receptor occurs at the plasma membrane upon ligand-induced activation.

We have previously shown that, although overexpression of mutant dynamin inhibits clathrin-dependent endocytosis and disrupts high affinity binding of epidermal growth factor (EGF) to the EGF receptor (EGFR), it does not inhibit ligand-induced translocation of the EGFR into clathrin-coated pits. In the present study, we demonstrate that, upon ligand binding and incubation at 37 degrees C, the EGFR was polyubiquitinated regardless of overexpression of mutant dynamin. In cells not overexpressing mutant dynamin, the EGFR was rapidly internalized and deubiquitinated. In cells being endocytosis-deficient, due to overexpression of mutant dynamin, however, the EGFR was upon prolonged chase first found in deeply invaginated coated pits, and then eventually moved out of the coated pits and back onto the smooth plasma membrane. Polyubiquitination occurred equally efficiently in cells with or without intact clathrin-dependent endocytosis, while the kinetics of ubiquitination and deubiquitination was somewhat different. We further found that the EGF-induced ubiquitination of Eps15 occurred both in the absence and presence of endocytosis with the same kinetics as polyubiquitination of the EGFR, but that the EGF-induced monoubiquitination of Eps15 was somewhat reduced upon overexpression of mutant dynamin. Our data show that EGF-induced polyubiquitination of the EGFR occurs at the plasma membrane.

Survival of infectious Pseudomonas aeruginosa genotypes in occupational saturation diving environment and the significance of these genotypes for recurrent skin infections.

BACKGROUND: Occupational saturation divers suffer from various skin disorders, of which skin infections are the most serious and frequent. Pseudomonas aeruginosa is the microbe most often isolated. METHODS: P. aeruginosa isolates from 292 skin infections in operational saturation divers and about 800 isolates from occupational saturation diving systems have been collected during the period 1986 to 1998. Genotyping of the isolates has been performed by using restriction enzyme fragmentation and pulsed field gel electrophoresis. RESULTS: Four hundred and seventy-two P. aeruginosa isolates have been analyzed, of which 181 originate from skin infections in divers. Ninety-seven significantly different P. aeruginosa genotypes have been defined. Some of these genotypes are solely found from skin infections, some solely from the saturation environment and about 25% were found both from infections and from the saturation environment. Eight frequent infectious genotypes have been identified, and these are shown to be present over several years, both in infections and in the saturation environment. CONCLUSIONS: The study suggests that skin infections in occupational saturation divers are commonly caused by environmental strains.

Epidermal growth factor increases the level of the cyclin-dependent kinase (CDK) inhibitor p21/CIP1 (CDK-interacting protein 1) in A431 cells by increasing the half-lives of the p21/CIP1 transcript and the p21/CIP1 protein.

DNA synthesis was inhibited in A431 cells by epidermal growth factor (EGF) in a p21/CIP1-dependent manner [where CIP1 is cyclin-dependent kinase (CDK)-interacting protein 1]. When 1 or 10 nM EGF was added, the level of p21/CIP1 was increased to the same extent, and the protein level peaked after approx. 5 h of incubation. The increase in p21/CIP1 mRNA upon addition of EGF was rapid, and was enhanced in the presence of cycloheximide. The half-life of p21/CIP1 mRNA in EGF-treated A431 cells was increased approx. 2-fold; this is in contrast with the case in MCF-7 cells with normal p53, in which the half-life of p21/CIP1 mRNA was not increased upon addition of EGF. This increased stability accounts for most of the increase in mRNA levels observed in A431 cells during short incubation periods. Additionally, upon prolonged incubation of A431 cells with EGF, the half-life of the protein was also increased compared with that in untreated cells and in cells treated with EGF for short time periods. Nuclear run-on assays demonstrated only marginal stimulation of transcription by 10 or 1 nM EGF, or by 10 ng/ml tumour necrosis factor alpha. Our results indicate that the most important mechanisms by which EGF increases p21/CIP1 protein levels in A431 cells are post-transcriptional and post-translational stabilization.

Endocytosed epidermal growth factor (EGF) receptors contribute to the EGF-mediated growth arrest in A431 cells by inducing a sustained increase in p21/CIP1.

We investigated the ability of endocytosed activated epidermal growth factor receptors (EGFR) to induce expression of the cyclin-interacting protein p21/CIP1 in A431 cells. Transforming growth factor alpha (TGFalpha) and EGF both induced tyrosine phosphorylation, induction of p21/CIP1, and thereby inhibition of DNA synthesis. TGFalpha is released from the EGFR when the TGFalpha-EGFR complex encounters low pH upon endocytosis. Consistently, we found more rapid dephosphorylation of the EGFR and less induction of p21/CIP1 by TGFalpha than by EGF. This difference was abolished upon neutralizing endosomal pH by the carboxylic ionophore monensin or the proton ATPase inhibitor bafilomycin A1. When surface-bound TGFalpha was removed by acid stripping and endosomal pH was neutralized with bafilomycin A1, TGFalpha stimulated EGFR tyrosine phosphorylation, induced p21/CIP1, and inhibited DNA synthesis. This strongly suggests that p21/CIP1 can be induced by endocytosed, activated EGFR and that endocytosed EGFR can affect cell growth.

High-affinity binding of epidermal growth factor (EGF) to EGF receptor is disrupted by overexpression of mutant dynamin (K44A).

Activation of the epidermal growth factor receptor (EGFR) kinase was analyzed in cells conditionally defective for clathrin-dependent endocytosis by overexpression of mutant dynamin (K44A). EGF-induced autophosphorylation of the EGFR on ice was strongly reduced in cells overexpressing mutant dynamin, and consistently, binding analyses showed that high-affinity EGFRs were lost. In the absence of mutant dynamin the cells displayed both high- and low-affinity EGFR. At 4 degreesC EGF-EGFR localized mainly outside coated pits regardless of expression of mutant dynamin. However, also low-affinity EGFR efficiently moved to coated pits upon incubating cells at 37 degreesC. Thus, expression of mutant dynamin disrupts high-affinity binding of EGF, but not ligand-induced recruitment of EGFR to clathrin-coated pits.

Progression of approximal caries in relation to iatrogenic preparation damage.

The aim of the present study was to evaluate the effect of iatrogenic preparation damage on the need for operative caries treatment of approximal surfaces, adjacent to Class II amalgam restorations. The material was collected by 77 dentists from the Public Dental Child Health Service in Denmark. It consisted of die-stone models of 187 first-time Class II preparations, adjacent to 190 unfilled approximal surfaces of 58 primary and 132 permanent teeth. The cavity preparations were performed in children between 4 and 17 years of age. They were all filled with amalgam. Information about operative treatment and exfoliation or extraction of the preparation teeth and the adjacent teeth during the following seven years was obtained from the patients' records. Stereomicroscopic examination of the models revealed preparation damage on 64% of the unfilled approximal surfaces in primary teeth and on 69% of the corresponding test surfaces in permanent teeth. During the observation period, operative treatment was performed on 10% of the undamaged test surfaces in primary teeth and on 35% of the damaged ones (p less than 0.05). The corresponding figures for test surfaces in permanent teeth were 6% and 15% (p less than 0.05). It is concluded that iatrogenic preparation damage is a frequent side-effect of operative intervention with approximal caries lesions, and represents a dental health problem, since the damage increases caries progression and the perceived need for restorative therapy of the adjacent teeth.

[Class I and II cavities for amalgam restorations]. / Klasse I-II kaviteter til amalgam.

In a Danish cross-sectional survey of replacements of fillings it was reported that a major reason for replacement of Class II amalgam restorations was bulk fractures (22). This initiated an examination of a sample of 168 Class II cavity preparations made by dentists from Denmark and other Scandinavian countries. The results showed that the Danish cavities were deepest occlusally and buccally, had the most converging proximal walls, and the broadest bucco-lingual outline occlusally. On the basis of the literature, it is not possible to evaluate the clinical significance of these differences and there is no distinct explanation why bulk fractures cause replacement of amalgam fillings more frequently in Denmark than in the rest of Scandinavia. Only a longitudinal clinical examination of the fillings may show whether the observed differences in the cavity preparations results in an increased frequency of isthmus fractures and are of importance for the longevity of the fillings.

Effects of cyclophosphamide on the in vivo response of outbred athymic (nude) mice to a thymus-independent antigen (DNP-AGG-Ficoll).

Both nude mice (nu/nu) and their heterozygous littermates (nu/+) were injected with a single IP dose of 300 mg cyclophosphamide (CY)/kg. CY is a known immunosuppressive agent, which affects primarily B lymphocytes. Immunization with the thymus independent antigen DNP-AGG59-Ficoll after CY treatment disclosed that restoration of the primary direct PFC response occurred more rapidly in nude mice than in nu/+ mice. However in these same experiments, the primary indirect PFC response, recovered earlier in nu/+ mice than in nude mice. After CY treatment, secondary indirect PFC responses were delayed in both nude and nu/+ mice, but the greatest effect was seen in nude mice. The data suggest that the presence of T cells has little if any influence on the recovery capacity of those B cells which are destined to become direct PFC. However the recovery of B cells which are destined to produce indirect PFC responses is facilitated by the presence of T cells.

Microstructure of inner surfaces on composite restorations related to filling procedure.

The inner surfaces of 40 Concise restorations placed in vivo on permanent molars have been studied by scanning electron microscopy. Only grinding traces could be seen on fillings from cavities which had not been etched, while the morphologic structure of the enamel and dentin was reflected on fillings from acid-etched cavities. Application of low-viscous non-composite resin in the cavities before filling with the composite resin did not influence the enamel pattern on the fillings, while the amount of processes of resin corresponding to the dentinal tubules in etched cavities was significantly increased. In the discussion the difference in surface structure of the fillings is correlated to marginal leakage along similar restorations.