Eight weeks of high-intensity interval training versus stretching do not change the psychoneuroendocrine response to a social stress test in emotionally impulsive humans

PURPOSE

Research supports physical activity as a method to heighten stress resistance and resilience through positive metabolic alterations mostly affecting the neuroendocrine system. High-intensity interval training (HIIT) has been proposed as a highly effective time-saving method to induce those changes. However, existing literature relies heavily on cross-sectional analyses, with few randomised controlled trials highlighting the necessity for more exercise interventions. Thus, this study aims to investigate the effects of HIIT versus an active control group on the stress response to an acute psychosocial stressor in emotionally impulsive humans (suggested as being strong stress responders).

METHODS

The study protocol was registered online (DRKS00016589) before data collection. Sedentary, emotionally impulsive adults (30.69 ± 8.20 y) were recruited for a supervised intervention of 8 weeks and randomly allocated to either a HIIT (n = 25) or a stretching group (n = 19, acting as active controls). Participants were submitted to a test battery, including saliva samples, questionnaires (self-efficacy- and perceived stress-related), visual analogue scales (physical exercise- and stress-related), and resting electroencephalography and electrocardiography assessing their reaction to an acute psychological stressor (Trier Social Stress Test) before and after the exercise intervention.

RESULTS

HIIT increased aerobic fitness in all participants, whereas stretching did not. Participants from the HIIT group reported perceiving exercising more intensively than those from the active control group (ƞp2 = 0.108, p = 0.038). No further group differences were detected. Both interventions largely increased levels of joy post-TSST (ƞp2 = 0.209, p = 0.003) whilst decreasing tension (ƞp2 = 0.262, p < 0.001) and worries (ƞp2 = 0.113, p = 0.037). Finally, both interventions largely increased perceived levels of general self-efficacy (ƞp2 = 0.120, p = 0.029).

CONCLUSION

This study suggests that 8 weeks of HIIT does not change the psychoneuroendocrine response to an acute psychological stress test compared to an active control group in emotionally impulsive humans. Further replications of supervised exercise studies highly powered with active and passive controls are warranted.

80% Valley Polarization of Free Carriers in Singly Oriented Single-Layer WS_{2} on Au(111)

We employ time- and angle-resolved photoemission spectroscopy to study the spin- and valley-selective photoexcitation and dynamics of free carriers at the K[over ¯] and K[over ¯]^{'} points in singly oriented single-layer WS_{2}/Au(111). Our results reveal that in the valence band maximum an ultimate valley polarization of free holes of 84% can be achieved upon excitation with circularly polarized light at room temperature. Notably, we observe a significantly smaller valley polarization for the photoexcited free electrons in the conduction band minimum. Clear differences in the carrier dynamics between electrons and holes imply intervalley scattering processes into dark states being responsible for the efficient depolarization of the excited electron population.

Staphtox predictor - A dynamic mathematical model to predict formation of Staphylococcus enterotoxin during heating and fermentation of meat products

Existing growth models for S. aureus predict growth in relation to temperature, a_w/NaCl and pH, and the assessment of probable Staphylococcus enterotoxin (SE) formation is based solely on the number of S. aureus. However, during the production of meat products such as fermented sausages and semi-processed hams, growth of S. aureus is a critical control point in HACCP plans. There is a need to develop a model that evaluates the safety of the product regarding SE formation in relation to the product composition, changes in pH or temperature during the processing and the number of S. aureus in the final product. The objective of the present work is to develop a mathematical model that predicts both the increase in the number of S. aureus and whether SE formation is possible in different meat product processes. A total of 78 experiments were carried out in a meat model system. The experiments covered a range of different temperatures (10-40 °C), pH (4.6-6.0), water phase salt (WPS) (2.2-5.6%) and Sodium nitrite concentrations (0-150 ppm). The meat model system was inoculated with approximately 10³ CFU/g of a multi-strain cocktail and incubated at the different temperatures. The cocktail consisted of three strains of S. aureus producing the Staphylococcus enterotoxins A to D (SEA to SED) and a methicillin-resistant strain producing SEG, SEI, SEM, SEN, SEO and SEU. Enumeration of S. aureus was performed several times during the incubation, SE was extracted from samples with >5 log CFU/g, and the SEA-E content was analysed by an ELISA method. Maximum growth rates and lag times calculated from microbiological data, together with temperature, pH, WPS and Sodium nitrite, were used to develop a SE and a growth model. The growth model was developed by training a neural network and the SE model based on logistic regression. The SE and growth models were validated on separate data sets (N = 200 SE model, N = 63 growth model) including both dynamic and static conditions. The SE model predicted all occurrences of toxin formation in the validation data sets. The growth model is a fail-safe model and the prediction errors are comparable to laboratory reproducibility. In conclusion, the models are applicable for predicting the increase in S. aureus and for evaluating if SE formation is likely during processing of meat products. The models are available to producers and other interested parties at www.dmripredict.dk.

Improved controlled atmosphere high temperature scanning probe microscope

To locally access electrochemical active surfaces and interfaces in operando at the sub-micron scale at high temperatures in a reactive gas atmosphere is of great importance to understand the basic mechanisms in new functional materials, for instance, for energy technologies, such as solid oxide fuel cells and electrolyzer cells. Here, we report on advanced improvements of our original controlled atmosphere high temperature scanning probe microscope, CAHT-SPM. The new microscope can employ a broad range of the scanning probe techniques including tapping mode, scanning tunneling microscopy, scanning tunneling spectroscopy, conductive atomic force microscopy, and Kelvin probe force microscopy. The temperature of the sample can be as high as 850 °C. Both reducing and oxidizing gases such as oxygen, hydrogen, and nitrogen can be added in the sample chamber and the oxygen partial pressure (pO2) is monitored by an oxygen sensor. We present here some examples of its capabilities demonstrated by high temperature topography with simultaneously ac electrical conductance measurements during atmosphere changes, electrochemical impedance spectroscopy at various temperatures, and measurements of the surface potential. The improved CAHT-SPM, therefore, holds a great potential for local sub-micron analysis of high-temperature and gas induced changes of a wide range of materials.

A new real-time PCR method for the identification of Salmonella Dublin

AIMS

Development of a real-time PCR method for the specific detection of Salmonella Dublin.

METHODS AND RESULTS

The method was directed towards a Salm. Dublin-specific sequence of the vagC gene on the Salmonella virulence plasmid (pSDV) and towards Salmonella genus-specific sequence of the invA gene, serving as an internal amplification control. The method showed 100% inclusivity and exclusivity when tested on a strain collection containing 50 serotyped S . Dublin strains, 20 strains of other Salmonella serotypes and 10 non- Salmonella strains. The method also showed 100% inclusivity and 99% exclusivity in a collaborative study comprising eight laboratories, where each laboratory received ten different S . Dublin strains and 10 other Salmonella serotypes.

CONCLUSIONS

The method showed excellent performance both when validated in the laboratory and in the collaborative study.

SIGNIFICANCE AND IMPACT OF THE STUDY

Application of the present method in food control, for example at slaughterhouses, can improve the contamination control of this veterinary and clinically important Salmonella serotype.

Osteopontin functionalization of hydroxyapatite nanoparticles in a PDLLA matrix promotes bone formation

We studied the osteoconductive tissue response of hydroxyapatite (HA) nanoparticles functionalized with osteopontin (OPN) in a matrix of poly-D,L-lactic-acid (PDLLA). In a canine endosseus 0.75-mm gap implant model, we tested the osteointegrative impact of the OPN functionalized composite as an implant coating, and a non-functionalized composite was used as reference control. During the four weeks of observation, the OPN functionalized composite coating significantly increased the formation of new bone in the porosities of the implant, but no differences were observed in the gap. The study provides evidence of its potential use either alone or in combination with other osteoconductive compounds.

Lithium Intercalation in Oxides: EMF Related to Structure and Chemistry

Experimental results for a number of oxide host materials as electrodes in lithium batteries are compared in order to obtain a better understanding of the factors influencing the emf-composition relationships. These factors are divided into two main groups: Those that are consequences of the structure of the host lattice, and those who follow from the chemistry of the host material. Series of materials with the same structure, but different chemical composition (spinels and MO2(B)) are compared, as well as series of materials with the same chemical composition, LixV2O5, but different structure. These data show that the potential level is mainly determined by the host chemistry, although destabilisation of the host can also give a significant contribution. The host structure will determine the width of the composition interval as well as the inflexions on the emf-curve. The possibility for tailoring the emf by using mixtures of transition metals in the host lattice is discussed.

Agreement between Cochrane Neonatal reviews and clinical practice guidelines for newborns in Denmark: a cross-sectional study

OBJECTIVE

To assess agreement between Cochrane Neonatal Group reviews and clinical practice guidelines in Denmark.

DESIGN

Retrospective analysis of clinical guidelines for newborn infants.

MATERIALS

All Cochrane neonatal reviews and Danish clinical guidelines for newborn infants.

MAIN OUTCOME MEASURES

The recommendations from the Cochrane reviews and local clinical guidelines were compared and classified as being in agreement, in partial agreement or in disagreement. Authors of guidelines were asked whether Cochrane reviews had been considered during guideline development and reasons for any disagreements. Heterogeneity among departments was assessed.

RESULTS

173 interventions evaluated in Cochrane neonatal reviews were included. All 17 Danish neonatal departments agreed to participate, but only 14 (82%) delivered data. Agreement between reviews and guidelines was observed for a median of 132 interventions (76%) (range 129-134), partial agreement was observed for 31 interventions (18%) (range 29-33), and disagreement was observed for 10 interventions (6%) (range 8-13) (kappa = 0.56, range 0.53-0.59). Most of the latter 10 interventions were not recommended in the reviews but were recommended in the guidelines. There were numerous reasons for disagreement, the most common being usage of evidence with higher bias risks than randomised trials in guidelines development. Overall, Cochrane reviews were rarely (10%) used during guideline development. For nine guideline topics (5%) there was diversity among the Danish departments' recommendations.

CONCLUSIONS

There is good agreement between Cochrane reviews and neonatal guidelines in Denmark. However, Cochrane reviews were rarely used for guideline development. Heterogeneity among guidelines produced by the various neonatal departments seems moderate.

Severe case of invasive community-acquired methicillin-resistant Staphylococcus aureus infection in Norway

Staphylococcus aureus, including methicillin-resistant strains (MRSA), may cause a wide range of infections involving skin and soft tissue, as well as bone, airways, and endovascular grafts.

Integrated modelling of nitrate loads to coastal waters and land rent applied to catchment-scale water management

The EU Water Framework Directive (WFD) requires an integrated approach to river basin management in order to meet environmental and ecological objectives. This paper presents concepts and full-scale application of an integrated modelling framework. The Ringkoebing Fjord basin is characterized by intensive agricultural production and leakage of nitrate constitute a major pollution problem with respect groundwater aquifers (drinking water), fresh surface water systems (water quality of lakes) and coastal receiving waters (eutrophication). The case study presented illustrates an advanced modelling approach applied in river basin management. Point sources (e.g. sewage treatment plant discharges) and distributed diffuse sources (nitrate leakage) are included to provide a modelling tool capable of simulating pollution transport from source to recipient to analyse the effects of specific, localized basin water management plans. The paper also includes a land rent modelling approach which can be used to choose the most cost-effective measures and the location of these measures. As a forerunner to the use of basin-scale models in WFD basin water management plans this project demonstrates the potential and limitations of comprehensive, integrated modelling tools.

Selective tuning of cortical sound-feature processing by language experience

In 'quantity-languages', such as Japanese or Finnish, sound duration is linguistically relevant. We showed that quantity-language speakers were superior to speakers of a non-quantity language in discriminating the duration of even non-speech sounds. In contrast, there was no group difference in the discrimination of sound frequency. This result, obtained both by behavioural and neural indices at attentive and automatic levels of processing, indicates precise feature-specific tuning of the auditory-cortex functions by the mother tongue.

Outbreak of methicillin-resistant Staphylococcus aureus in two nursing homes in Central Norway

Until recently, infections with methicillin-resistant Staphylococcus aureus (MRSA) have mainly been associated with hospital outbreaks in Norway. However, increasingly cases are contracted outside hospitals. This paper reports the first two outbreaks of MRSA in two nursing homes in central Norway, affecting 23 residents and five staff members. Pulsed-field gel electrophoresis analysis showed that all strains from nursing home A were identical and that the strains from nursing home B were genotypically similar with one or two band differences. Multi-locus sequence typing (MLST) showed that the strains from the two nursing homes belong to clonal complex 45, with each strain being a single-locus variant of sequence type 45 (ST 45), a well-known European epidemic strain. No evident source of the two outbreaks was found, and there was no obvious connection between the two outbreaks. The latter is also supported by the minor differences observed by MLST, suggesting a connection at some time in the past. The outbreaks led to a heavier workload and economic strain on both nursing homes. The outbreak in nursing home A was brought to an end, whereas two residents remained colonized in nursing home B despite several eradication attempts. These outbreaks show the potential for MRSA spread in a nursing home. If the prevalence of MRSA in Norway continues to increase, nursing home staff and residents may have to be included in the groups to be screened for MRSA upon hospital admission.

Application of Leuconostoc carnosum for biopreservation of cooked meat products

AIMS

To optimize the practical use of the bacteriocin producing Leuconostoc carnosum 4010 in order to inhibit the growth of Listeria monocytogenes in sliced meat products.

METHODS AND RESULTS

Four different methods for biopreservation using the partially purified bacteriocin or the living culture of Leuc. carnosum 4010 were evaluated. The methods using the living protective culture added to the sliced gas packed meat product were more effective in preventing growth of L. monocytogenes than the use of the partially purified leucocins 4010 or bacteriocin produced during fermentation before heat treatment of the saveloy. The application method giving the highest reduction in L. monocytogenes used nozzles for sprinkling the protective culture on all surfaces of each slice of the meat product. In the control samples without the protective culture, L. monocytogenes grew to ca. 107 CFU g(-1), whereas for the application method using nozzles for distributing the protective culture, counts of L. monocytogenes never exceeded 10 CFU g(-1) during 4 weeks of storage at 10 degrees C.

CONCLUSIONS

The live cells of the bacteriocin producing Leuc. carnosum 4010 was the most efficient method as it inhibited the growth of L. monocytogenes in cooked, sliced and gas packed saveloy stored at 5 and 10 degrees C for 4 weeks.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results indicate that biopreservation with lactic acid bacteria is a suitable alternative to chemical preservatives. An even distribution of the protective culture was found to be essential for the efficacy of the protective culture in pilot plant trials.

Facilitation of visual search at new positions: a behavioral and ERP study of new object capture

Visual search was studied in two consecutive displays. Display 1 items changed identity whilst retaining their positions when the additional items appeared in Display 2. In the New condition, the target appeared at one of the new positions, whereas in the Old condition, the target appeared at one of the old positions. Responses were faster and accuracy increased in the New condition. Event-related brain potentials revealed an Old-New difference 400 ms after Display 2 onset for the smaller set size, suggesting that subjects had a holistic impression that the target was absent at a new position. A posteriorly distributed processing difference between both conditions was manifest at around 1200 ms, suggesting a bias for search at new positions.

Is there pre-attentive memory-based comparison of pitch?

The brain's responsiveness to changes in sound frequency has been demonstrated by an overwhelming number of studies. Change detection occurs unintentionally and automatically. It is generally assumed that this brain response, the so-called mismatch negativity (MMN) of the event-related brain potential or evoked magnetic field, is based on the outcome of a memory-comparison mechanism rather than being due to a differential state of refractoriness of tonotopically organized cortical neurons. To the authors' knowledge, however, there is no entirely compelling evidence for this belief. An experimental protocol controlling for refractoriness effects was developed and a true memory-comparison-based brain response to pitch change was demonstrated.

Insight into mental illness and child maltreatment risk among mothers with major psychiatric disorders

OBJECTIVES

This study examined the relationship between insight into mental illness and current child maltreatment risk among mothers who had a major psychiatric disorder and who had lost custody of a child because of abuse, neglect, or having placed the child at risk of harm. Specifically, a measure of insight was examined in relation to systematically observed parenting behaviors known to be correlated with past child maltreatment and in relation to a comprehensive clinical determination of risk.

METHODS

Forty-four mothers who had a major psychiatric disorder were independently rated for their insight into their illness, the quality of mother-child interaction, and the overall clinical risk of maltreatment.

RESULTS

Better insight into mental illness was associated with more sensitive mothering behavior and with lower assessed clinical risk of maltreatment. The association remained when mothers with current psychotic symptoms were excluded from the analyses. Better insight did not appear to be associated with past psychotic symptoms, maternal psychiatric diagnosis, or the mother's level of education.

CONCLUSIONS

Insight into mental illness may function as a protective factor that influences the risk of child maltreatment in mothers with mental illness. Measures of insight could be usefully incorporated into comprehensive parenting assessments for mothers with psychiatric disorders.

Maternal expressed emotion related to attachment disorganization in early childhood: a preliminary report

Using a longitudinal sample of children, this study examined the relation between maternal Expressed Emotion (EE) and mother-child attachment disorganization at age 6 years. A nonclinical sample of 33 children (at ages 12 months and 18 months) from Berlin, Germany participated with their mothers in Ainsworth's Strange Situation. Thirty-two children were again observed with their mothers at age 6 years in a standard laboratory attachment observation. At the time of the 6-year assessment, maternal EE was assessed based on a Five-Minute Speech Sample. Mothers also completed the Life Events Questionnaire, a measure of family stress, and the Present State Examination, a measure of maternal depression. Maternal Expressed Emotion was significantly linked to mother-child attachment security at age 6 years. Further analyses revealed that High EE was most closely linked to the disorganized attachment pattern at age 6 years, an at-risk attachment pattern that has been associated with intrusive and hostile maternal behavior. The relationship was upheld when other relevant variables, including infant attachment disorganization and a measure of perceived family stress, were simultaneously considered. The study provides independent validation of Expressed Emotion as a measure of relationship quality in early childhood. It also provides a basis for the further investigation of the nature of the relation between maternal Expressed Emotion and attachment disorganization.

Calcium leaching from dentin and shear bond strength after etching with phosphoric acid of different concentrations

Based on the H2O-P2O5-CaO phase diagram, we hypothesize that a phosphoric acid concentration around 27 wt% leaches most calcium from dentin. We also hypothesize that bond strength is affected by resin infiltration, and that resin infiltration becomes incomplete when calcium leakage exceeds a certain value. Dentin disks were cut from human molars. Eight phosphoric acid concentrations were prepared (15.7-51.2 wt%). For each acid group, there were four etch time subgroups (15, 30, 60 and 120 s). The dentin disks were etched in acid and rinsed in water for times corresponding to 15 s, 30 s, 60 s and 120 s. The calcium concentrations were analyzed using atomic absorption spectroscopy. Composite cylinders were bonded to the remaining parts of the teeth using the same etching protocol, and shear bond strength was determined. The 29.2 wt% group demonstrated the highest and the 15.7 wt% group the lowest calcium leaching value. Even though there were trends towards lower bond strength for longer etch times, a statistically significant difference was only found between 30 and 120 s. There was no significant correlation between calcium leaching and bond strength. The results support the tested hypothesis that the highest leaching value would be around 27 wt% phosphoric acid.

Effects of grammatical gender on picture and word naming: evidence from German

The present study investigated the effects of prior grammatical gender information (masculine, feminine, and neuter) provided by a minimal sentence context on both picture- and word-naming latencies. Named targets were nouns or pictures of concepts featuring unambiguous grammatical gender. Simple sentence fragments were presented auditorily prior to each picture or word target; the relation between these sentence primes and the word or picture target was either gender-congruent, gender-incongruent, or gender-neutral. Relative to the gender-neutral baseline, reliable facilitation and inhibition effects were both observed in the picture-naming task. By contrast, only inhibition effects were observed in the word-naming task. The results suggest that the processes of picture and word naming differ qualitatively when gender information is precued. The findings are discussed with respect to the distinction between postlexical and intralexical loci of the effects of gender context on word recognition and production.

Effect of various salts on the stability of lansoprazole, omeprazole, and pantoprazole as determined by high-performance liquid chromatography

A fast and reproducible reverse-phase high-performance liquid chromatography (HPLC) assay method has been developed for the simultaneous quantitation of omeprazole, lansoprazole, and pantoprazole. The three compounds were monitored at 280 nm using Zorbax Eclipse XDB C8 (5 microns, 150 cm x 4.6 mm i.d.) and a mobile phase consisting of 700:300 phosphate buffer:acetonitrile with the pH adjusted to 7.0 with phosphoric acid. The method was used to study the effect of pH and various salts on the stability of the three compounds. The pH rate profile curve showed that pantoprazole was the most stable compound and lansoprazole the least stable. The stabilities of the compounds in salt solutions were found to be in the following order: phosphate buffer < trisodium citrate < citrate buffer < or = acetate buffer < citric acid < or = monosodium citrate < or = calcium carbonate < sodium bicarbonate < sodium chloride < water. The rate of degradation had a direct relationship with the H+ and salt concentration.

Expression of the psoriasis-associated antigen, Pso p27, is inhibited by cyclosporin A

The psoriasis-associated antigen, pso p27, can be isolated from psoriasis scale and is present in complement-activating immune complexes in psoriatic scale, and in serum from patients with psoriasis. The antigen is produced by tryptase-positive cells in the skin lesions and is shown to be a major antigen in the immune reactions in psoriasis. The synthesis of this particular antigen is reduced with the remission of inflammation in the skin lesions. In this study we followed 3 patients with severe plaque psoriasis during treatment with cyclosporin A. In all patients we observed a decrease in the expression of the antigen pso p27 during the therapy. The effectiveness of the therapy varied among the patients, but there was a clear correlation between disease activity and expression of the antigen pso p27 as demonstrated by immunofluorescence in biopsies from selected skin lesions. This observation strengthens our hypothesis that the pso p27 antigen plays an important role in the inflammation in psoriasis.

Development of a sodium dodecyl sulfate-polyacrylamide gel electrophoresis reference method for the analysis and identification of fish species in raw and heat-processed samples: a collaborative study

A collaborative study was carried out in seven European labs with the aim of achieving a sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) standard operation procedure to identify fish species in raw and cooked samples. Urea and SDS-containing solutions were evaluated as extractants. Several preelectrophoretic operations--such as treatment with RNase/DNase, ultrafiltration and desalting--and up to ten types of gels and three SDS-PAGE systems were considered. The SDS-containing solution allowed a higher protein extractability than urea. Unlike urea extraction, SDS extraction seemed not to be influenced so much by the state of the sample (raw, cooked at 60 degrees C, cooked at 85 degrees C). Desalting, ultrafiltration or treatment with RNase/DNase did not improve the discriminatory power of the protein patterns. Commercial homogeneous 15% ExcelGels, especially when they were silver stained, yielded good results and afforded higher reproducibility, thus allowing a better matching of results among the laboratories participating in this collaborative study. Under the optimized technical conditions described above, all the fish species tested, either raw and cooked, yielded reproducible and discriminant species-specific protein patterns.

Effects of consciousness on human brain waves following binocular rivalry

When the two eyes of an observer are exposed to conflicting stimuli, they enter into binocular rivalry and the two possible percepts will alternate in dominance. We investigated neural activity and its time course following binocular rivalry by measuring human event-related brain potentials to transitions from rivalrous to non-rivalrous stimulation. When these changes did not entail a change in conscious perception they elicited a markedly attenuated N1 component and a delayed and attenuated P3 peak as compared to percept-incompatible changes and non-rivalrous control conditions. These results suggest that in humans binocular rivalry is resolved at latest in extrastriate visual areas.

Low faecal carrier rate of vancomycin resistant enterococci in Norwegian hospital patients

The faecal carrier rate of vancomycin resistant enterococci (VRE) was surveyed among 616 patients in selected departments of 7 Norwegian hospitals. One Enterococcus gallinarum isolate harbouring a vanB2 element was recovered from a child with malignant disease treated with vancomycin and ceftazidime. No vancomycin resistant Enterococcus faecalis or Enterococcus faecium were detected and no VRE isolates of the VanA type were identified. The low level of VRE carriage corresponds to the limited use of glycopeptide antibiotics for human therapeutic purposes in Norway. It indicates a low risk of acquiring VRE infections in Norwegian hospitals.

Assessing children's representational attachment models: links to mother-child attachment quality in infancy and childhood

The authors examined whether the finding of a correspondence between specific behavioral patterns of attachment in infancy and childhood and specific representational patterns in childhood could be replicated using children's responses to a story depicting an imagined parent-child separation experience. The participants were 33 German mothers and their children (16 girls, 17 boys). Attachment quality was assessed via standard and exploratory attachment observations at ages 12 months, 18 months, and 6 years. Chi-square analyses indicated that there was a good level of concordance between the behavioral and representation attachment patterns in infancy and childhood.

[Bacteremia with granulocytopenia--microbiology and empiric antibiotic treatment]

This article sums up a retrospective analysis of 84 episodes of bacteraemia in acute leukaemia patients with severe neutropenia in a Norwegian teaching hospital during the period 1990-95. Gram negative bacteria represented 54% of the blood culture isolates, all of which were susceptible to aminoglycosides, and nearly all to ceftazidime and imipenem. Penicillin/aminoglycoside was used as initial therapy in 43% of the episodes. Initial empiric therapy was modified in 52% of the events. Only 15% of patients receiving the penicillin/aminoglycoside combination actually had infections with organisms susceptible to penicillin. Only 2% of patients with gram negative infections received initial synergistic treatment with two effective drugs. Mortality from infections was 8% in acute leukaemia patients with documented bacteraemia. Deaths mainly occurred in patients with terminal leukaemia disease. Late breakthrough bacteraemias with Stenotrophomonas maltophilia and Pseudomonas aeruginosa caused 50% of all fatal infections. The analysis suggests that no patients died during initial bacteraemia with penicillin-resistant organisms treated with penicillin/aminoglycoside. The antibiotic susceptibility of the isolated bacteria was favourable compared to what has been found in other countries. For the time being, we believe that the ecological advantages of using penicillin/aminoglycoside as initial empiric treatment of febrile neutropenia are greater than the disadvantages.

Effect of primer solvent, primer agitation, and dentin dryness on shear bond strength to dentin

PURPOSE

To evaluate the shear bond strength of acetone- or water-based primers applied with or without agitation to either wet or dry dentin.

MATERIALS AND METHODS

Forty-eight caries-free extracted human premolars were embedded in gypsum and flat dentin surfaces were prepared. The teeth were randomly divided in eight groups with six specimens each. After acid etching and rinsing, either a HEMA and acetone (Ac) or a HEMA and water (Wa) primer were applied to dry (D) or wet (W) dentin. The primer was placed with (Y) or without (N) agitation according to the following combinations: Group 1: D-Ac-Y; Group 2: D-Ac-N; Group 3: D-Wa-Y; Group 4: D-Wa-N; Group 5: W-Ac-Y; Group 6: W-Ac-N; Group 7: W-Wa-Y; Group 8: W-Wa-N. The primed surface was dried, covered with a bonding resin and light-cured, whereupon a composite cylinder was bonded to the dentin surface. The shear bond strength was determined after 30 days in water.

RESULTS

The mean and standard deviations, expressed in MPa, were: Group 1: 13.1 +/- 3.42; Group 2: 15.9 +/- 4.84; Group 3: 19.8 +/- 6.64; Group 4: 18.6 +/- 5.18; Group 5: 16.5 +/- 5.25; Group 6: 25.5 +/- 4.79; Group 7: 21.9 +/- 4.94; Group 8: 17.4 +/- 4.50. The results were analyzed using ANOVA and Waller-Duncans K-ratio t-test. The acetone-based primer gave the highest bond strength to wet dentin without agitation. When the acetone-based primer was used on dry dentin a significant decrease in bond strength occurred (P < 0.05). No significant difference (P > 0.05) was found for the water-based primer on wet or dry dentin. Agitation improved the bond strength for the water-based primer, but decreased the bond strength for the acetone-based primer.