Prevalence and genetic diversity of Staphylococcus aureus small-colony variants in cystic fibrosis patients

Staphylococcus aureus small-colony variants (SCVs) are being isolated more frequently in cystic fibrosis (CF) patients. We aimed to determine the prevalence of S. aureus SCVs and their phenotypic and genotypic properties in CF patients admitted to a university hospital. Specimens of 248 patients were examined during a period of 11 months. Colonies supposed to be SCVs were evaluated on Columbia blood agar, mannitol salt agar, and brain–heart infusion agar with 5% NaCl (BHIA 5% NaCl). Strains were confirmed by S. aureus nucA PCR. Antibiotic susceptibilities of SCVs and simultaneously isolated S. aureus strains were determined for oxacillin, gentamicin, trimethoprim–sulphamethoxazole, vancomycin, ciprofloxacin, linezolid, and tigecycline. Genetic relatedness between SCVs and normal S. aureus strains was determined with a pulsed-field gel electrophoresis (PFGE) method. S. aureus SCVs were detected in 20 of 248 patients (8.1%). The highest SCV isolation rate was obtained with MSA, followed by BHIA 5% NaCl. Auxotrophism for thymidine was demonstrated in six SCVs. The tigecycline susceptibilities of 48 SCV strains isolated in this study showed higher MIC values than those of 33 simultaneously isolated normal S. aureus strains. Whereas SCVs and normal S. aureus strains showed identical genotypes in 14 of the patients, five patients showed different genotypes. This first study from Turkey evaluating S. aureus SCVs in CF patients has indicated the importance of considering and reporting SCVs in chronic infections such as CF. The presence of SCVs will probably indicate persistent infection, and this might impact on antibiotic treatment decisions, as they are more resistant to antibiotics.     

Renin and heart rate responses to haemorrhage are age dependent in conscious lambs

The present experiments were carried out in conscious lambs (1-2 weeks old, n = 9) and older sheep (11-12 weeks old, n = 11) to determine whether the cardiovascular and endocrine responses to 0, 10 and 20 % haemorrhage were developmentally regulated. The major novel finding of our study is that throughout the first 3 months of postnatal life, there is a similar decrease in mean arterial pressure and a similar restoration of pressure to pre-haemorrhage levels, for the same degree of blood loss, yet the mechanisms used to restore pressure appear to be age dependent as follows. In lambs, but not in older sheep, heart rate increased for 1 h after 20% haemorrhage. Activation of the renin-angiotensin system was also greater and more prolonged in lambs than in older sheep following haemorrhage, and occurred at a lesser degree of blood loss. Plasma arginine vasopressin responses to haemorrhage were, however, similar in both age groups. These data provide new information that some of the mechanisms used to restore arterial pressure following blood volume depletion appear to be age dependent.     

Optimal management of distal ureteric strictures following renal transplantation: a systematic review

Our objective was to define optimal management of distal ureteric strictures following renal transplantation. A systematic review on PubMed identified 34 articles (385 patients). Primary endpoints were success rates and complications of specific primary and secondary treatments (following failure of primary treatment). Among primary treatments (n = 303), the open approach had 85.4% success (95% CI 72.5–93.1) and the endourological approach had 64.3% success (95% CI 58.3–69.9). Among secondary treatments (n = 82), the open approach had 93.1% success (95% CI 77.0–99.2) and the endourological approach had 75.5% success (95% CI 62.3–85.2). The most common primary open treatment was ureteric reimplantation (n = 33, 81.8% success, 95% CI 65.2–91.8). The most common primary endourological treatment was dilation (n = 133, 58.6% success, 95% CI 50.1–66.7). Fourteen complications, including death (4 weeks post‐op) and graft loss (12 days post‐op), followed endourological treatment. One complication followed open treatment. This is the first systematic review to examine the success rates and complications of specific treatments for distal ureteric strictures following renal transplantation. Our review indicates that open management has higher success rates and fewer complications than endourological management as a primary and secondary treatment for post‐transplant distal ureteric strictures. We also outline a post‐transplant ureteric stricture evaluation and treatment algorithm.     

Regional versus general anesthesia for donor nephrectomy: effects on graft function

Various general and regional anesthesia methods are used successfully in living-donor kidney transplantation. This study compared kidney graft function after general versus combined spinal-epidural anesthesia for donor nephrectomy. The study groups included recipients who received grafts from donors who had undergone nephrectomy under general anesthesia (GA group; n=10), and recipients who received grafts from donors who had combined spinal-epidural anesthesia (CSE group, n=10). Standard continuous epidural anesthesia was administered during all transplantations. Graft function was assessed using scintigraphy and Doppler ultrasonography on days 3 and 7. Urine levels of microalbumin, creatinine, and creatinine clearance rate were measured/calculated in 24-hour urine samples collected on postoperative days 3 and 7. There were no differences on either day 3 or day 7 with respect to glomerular filtration rate, microalbuminuria, or creatinine clearance rate (P >.05 for all). There were also no differences between the groups with respect to other scintigraphic findings on day 3 or day 7 (P >.05 for all). Ultrasonography on day 7 showed significantly higher mean peak systolic flow in the main renal artery in the CSE group than in the GA group (P=.035). The results suggest that GA and CSE for donor nephrectomy have similar effects on kidney graft function in recipients.     

Biofilm reduction and staining potential of a 0.05% chlorhexidine rinse containing essential oils

To cite this article:
Int J Dent Hygiene 9 , 2011; 60–67
DOI: 10.1111/j.1601‐5037.2009.00437.x
Hofer D, Meier A, Sener B, Guggenheim B, Attin T, Schmidlin PR. Biofilm reduction and staining potential of a 0.05% chlorhexidine rinse containing essential oils. Abstract: Objectives: To assess the biofilm reduction and discolouration potential of a new 0.05% chlorhexidine (CHX) digluconate solution, containing additional essential oil and alcohol components, compared with that of standard control CHX solutions (0.05% and 0.2% CHX). Methods: The potential to reduce total viable counts of growing mixed microbial populations was examined using the Zurich biofilm model. Biofilms were created on sterile pellicle‐coated hydroxyapatite discs and exposed to test substances at different time points. After 64.5 h, mean colony‐forming units and SDs were determined. Colour change measurements using light reflection analysis were carried out on saliva preconditioned bovine dentin and enamel samples, as well as on composite and glass ceramic restorative materials, after successive immersions in a standardized tea brew and the CHX solutions. Results: The test solution was able to reduce biofilm formation by 3 log steps compared with a negative (water) control. This was significantly less effective than the standard control CHX solutions, which reduced viable counts by 6 log steps. Both the test and control solutions exhibited staining on all surfaces. Staining was most pronounced on dentin, followed by enamel and to a significantly lesser degree on the restorative materials. Furthermore, the staining caused by the test solution on these restorative materials was generally lower than that caused by the control solutions. Conclusions: The test solution exhibited an antimicrobial activity. The composition, however, seems to hamper its effectiveness. Accordingly, it produced statistically significant, although by trend less, staining on restorative materials.     

Influence of fluoride concentration and ethanol pre-treatment on the reduction of the acid susceptibility of enamel

Objective

To determine the association between KOH-soluble and structurally bound fluoride uptake and the erosion resistance of enamel, respectively. Additionally, the effect of enamel pre-treatment with ethanol before fluoridation was assessed.

Methods

Sixty bovine incisors (4 specimens/tooth) were randomly allocated to six groups (A-F). Samples 1 and 2 remained untreated, serving as control at baseline. Pre-treatment of the samples was performed for 5 min with 99% ethanol (groups A, B and C) or physiologic saline (groups D, E and F). Samples 3 and 4 were treated either with 0.5% (groups A and D), 1.0% (groups B and E) or 1.5% (groups C and F) fluoride solution. In samples 1 and 3, uptake of KOH-soluble and structurally bound fluoride was determined. Samples 2 and 4 were used for the determination of acid susceptibility by immersion in 1 ml HCl for 30 s. Calcium release into HCl was assessed by atomic absorption spectroscopy. Differences between the groups were calculated by unpaired t-tests (p < 0.05).

Results

Mode of pre-treatment showed no influence on fluoride acquisition. KOH-soluble and structurally fluoride uptake increased with increasing fluoride concentrations. Highest acid resistance was observed after treatment with 1% fluoride solution for both kinds of pre-treatment followed by 1.5% and 0.5% fluoride solution.

Conclusion

Dose-dependency was observed for enamel fluoride acquisition but not for acid resistance.     

Impairment of the mitochondrial oxidative response to D-glucose in pancreatic islets from adult rats injected with streptozotocin during the neonatal period

Summary Pancreatic islets removed from adult rats injected with streptozotocin during the neonatal period display an impaired secretory response to D-glucose and, to a lesser extent, to L-leucine. Despite normal to elevated hexokinase and glucokinase activities in the islets of these glucose-intolerant animals and despite normal mitochondrial binding of the hexokinase isoenzymes, the metabolic response to a high concentration of D-glucose is severely affected, especially in terms of D-[6-¹⁴C]glucose oxidation. Thus, the ratio in D-[6-¹⁴C]glucose oxidation/D-[5-³H]glucose utilization is much less markedly increased in response to a rise in hexose concentration and, at a high concentration of D-glucose (16.7 mmol/l), less markedly decreased by the absence of Ca²⁺ and presence of cycloheximide in diabetic than control rats. This metabolic defect contrasts with (1) a close-to-normal or even increased capacity of the islets of diabetic rats to oxidize D-[6-¹⁴C]glucose, [2-¹⁴C]pyruvate, L-[U-¹⁴C]glutamine and L-[U-¹⁴C]leucine at low, non-insulinotropic, concentrations of these substrates; (2) a lesser impairment of the oxidation of L-[U-¹⁴ C]leucine tested in high concentration (20 mmol/l), the effect of Ca²⁺ deprivation upon the latter variable being comparable in diabetic and control rats; (3) an unaltered transamination of either [2-¹⁴ C]pyruvate or L-[U-¹⁴C]leucine; and (4) a modest perturbation of glycolysis. The most obvious alteration in glycolysis consists in a lesser increase of the glycolytic flux in response to a rise of D-glucose concentration in diabetic than control rats, this coinciding with an apparent decrease in affinity of glucokinase for the hexose. It is speculated that the preferential impairment of the metabolic and secretory response to D-glucose may be mainly attributable to an altered coupling between calcium accumulation and the stimulation of oxidative events in Beta-cell mitochondria of diabetic rats.     

Dentin enhances the effectiveness of bioactive glass S53P4 against a strain of Enterococcus faecalis.

OBJECTIVE: The aim of the current study was to test the impact of dentin powder on the antimicrobial efficacy of bioactive glass S53P4 (BAG). STUDY DESIGN: BAG was suspended (preincubated) in saline at 37 degrees C for different time periods with or without human dentin powder, hydroxylapatite, or decalcified dentin. Subsequently, Enterococcus faecalis ATCC 29212 cells were added to these suspensions and bacterial recovery measured with and without the use of gentle sonication. Furthermore, survival of bacteria in test and control suspensions was assessed over time. Supernatants of suspensions were analyzed for their element contents using atomic absorption spectrophotometry. The effects of pH, silica, and osmolarity on E faecalis viability were assessed using specifically prepared solutions. RESULTS: BAG preincubated with dentin powder caused a significant (P < .05) decrease in viability compared to pure BAG suspensions. This was not based on adherence of bacteria to solid particles or agglutination of the cells, because sonication did not increase bacterial yields. Hydroxylapatite and decalcified dentin did not increase BAG killing efficacy. The additive effect of BAG + dentin powder was dose dependent, occurred only with solids in suspension, and increased with suspension time. An augmented dissolution of glass components, especially silicon, was measured in BAG + dentin powder compared to pure BAG suspensions or counterparts containing hydroxylapatite or decalcified dentin. High osmolarity per se did not affect E faecalis viability, whereas high pH and silica levels did. CONCLUSION: The observed phenomenon was related to an increased BAG dissolution triggered by dentin powder, causing elevated local pH and silica levels.     

Predatory journal preference in the field of Orthopaedics and Traumatology in Turkey

ObjectiveThe aim of this study was to determine the prevalence of predatory journals in Orthopedics and Traumatology and to investigate the relationship of these publications with the regulations of scientific fields made in recent years in Turkey.MethodsThe journals and publishers between the years 2000–2018 were screened and websites visited one by one on the basis of the orthopedic journals and publishers list determined as predators or possible predators. Orthopedic publications originated from Turkey was detected in these predatory journals. Article admissions, article processing charges, editorial and referee average response times were reviewed from the websites of journals. In addition, the effect of changing associate professorship application requirements and academic incentive regulation on the preference of predatory journals was examined.ResultsBetween 2000 and 2018 years 1626 issues which can be reached in 282 journals were examined. 4795 articles were screened in 29 journals which have articles originated from Turkey. One hundred and six (2.21%) articles which originated from Turkey was reached in these publications. Average article processing charge was $865 ($ 0–1819). Fifty-nine of 106 (55%) articles originated from Turkey were found in only 4 journal. Journals which have articles originated from Turkey were not on the Web of Science list. The response time to the articles was between 2 and 6 weeks in these journals. After the change criteria in associate professorship in 2016, 3.32 fold increase in annual average number of publications originated from Turkey have been identified in predatory journals. After the change criteria in academic incentive regulation in 2015, 4.76 fold increase in annual average number of publications originated from Turkey have been identified in predatory journals.ConclusionThe number of articles in predatory journals is increasing all over the world. This situation also valid in the field of Orthopaedics and Traumatology in Turkey. Authors should pay attention regarding predatory journals not only article processing charges but also very short evaluation period.     

Infantile tuberous sclerosis changes in the brain: proton MR spectroscopy findings.

A parietal hamartoma of a three-month-old boy with tuberous sclerosis was studied with magnetic resonance (MR) imaging, and proton MR spectroscopy. MR spectra were obtained with the single-voxel PRESS (point resolved spectroscopy; TR = 1500 ms, TE = 135 ms) sequence, in a 8 cc region of interest. Apparently low NAA/Cho (0.28), and NAA/Cr (0.37) ratios were noted in the hamartoma, that could suggest a neoplasm. The lesion and the surrounding brain tissue were studied again after seven months with spectroscopic imaging using the chemical shift sequence (TR = 1500 ms. TE = 40 ms). This study revealed apparently improved NAA/Cho (2.63), NAA/Cr (2.13) ratios in the hamartoma compared to the initial examination at three months of age, excluding the possibility of a neoplasm.