Search

Cyclophosphamide is a hazardous cytostatic drug, which should be removed from wastewaters before disposals. Ozonation slowly inactivates this substance, requiring long reaction times to obtain degradation. In this paper, different advanced oxidation processes (AOPs) are studied for cyclophosphamide oxidative degradation in aqueous medium: ozone at several basic pH values, ozone/hydrogen peroxide at neutral and basic pHs with the addition of the peroxide at the beginning of ozonation. The influence of ozone concentration in the gas phase and gas flow is also discussed. Results show that, under the experimental conditions studied, the radical mechanism acting in the AOPs rapidly degrades cyclophosphamide. Additionally, second-order rate constants kd and kOH were determined for direct (molecular) and indirect (radical) reactions. Finally, reactions were carried out with the aim of isolating and identifying some of the degradation products. From ozonation at pH 9, 4-ketocyclophosphamide was identified as the main reaction product. [ABSTRACT FROM AUTHOR]

Catheter-associated urinary tract infection (CAUTI) is a relevant problem in health centers because of its high frequency., Objective: To identify UTI risk factors in adult patients with urinary catheter., Material and Method: Control case study carried out between the years 2010-2016 at the Military Hospital of Santiago, Chile. Univariate and multivariate statistical analysis were performed using the binary logistic regression model, variables such as age, duration and indication of the device, some comorbidities and the installation of the device after 15 days of hospitalization., Result: A total of 63 cases and 123 controls were obtained. Predictive variables of CAUTI for the duration of the urinary catheter from the 7th day onwards (OR 2.6 IC 1.4-4.9, p = 0.004) and the installation of the urinary catheter with a previous hospital stay of 15 days and more (OR 7.8 CI 2.9-20.9 p = 0.000). No association was found in age over 80 years, comorbidities such as diabetes and neurogenic bladder and indication., Conclusions: The results permitted to focus the interventions, evaluating the real need for indication of CUP in patients with previous hospital statistics of 2 weeks and encouraging the withdrawal of CUP before the 7th day of use.

Background: Health-care-associated infections are a frequent problem in hospital environments. Hand hygiene is the most effective measure to prevent outbreaks. The use of certain accessories could decrease its effectiveness, facilitating horizontal transmission of pathogens., Objective: Analyze the evidence that assess the impact of the use of rings and nail polish on hand hygiene quality in healthcare workers., Methods: Non-systematic search in PUBMED/MEDLINE database (1978-2018) of studies in which the quality of hand hygiene or surgical washing is measured, using quantitative cultures or fluorescent stains., Results: Wearing rings: 13 studies met the inclusion criteria. Seven were carried out in general wards. In all of them the use of rings was associated with lower quality of hand hygiene (the majority of low quality). Contrarily, in 3 of 4 primary studies carried out in the operating rooms (of low quality), their use did not affect the quality of surgical washing. Similarly, two systematic reviews obtained similar conclusions. Nail polish: 7 of 54 studies met the inclusion criteria. In four of them there were discordant results (the majority of low quality). One RCT showed a reduction in the quality of surgical washing only when the nail polish was damaged. Gel nail polish was associated with lower quality in two experimental studies., Conclusions: There is insufficient evidence to associate the use of these accessories with the reduction in the quality of hand hygiene. Its safety was not proven neither. Based on the available evidence (the majority of low quality), a negative impact of the use of rings in clinical units and also of damaged nail polish in operating rooms was observed. Better quality studies are required to address these relevant issues.

Background: Health personnel are exposed to accidents with blood and other potentially infectious biological fluids in their clinical practice. Management of these events has high costs that are likely to be reduced., Aim: To give a general description of work accidents and their associated costs., Material and Method: All healthcare workers reports of exposure to blood or risk fluids between 2010 and 2015, were included. Health care costs were calculated. Records were analyzed in a retrospective manner., Results: 189 exposures to risk fluids were reported during the study period with an average of 31 accidents per year. 83.5% of the studied sources were negative for HIV, HBV and HCV, 12.6% was with unknown source and only 3.7% was positive for any of them. The costs associated with management of risk exposures was $ 2,765,890 Chilean pesos/year (4,274 USD). The average cost per event was $ 73,171 Chilean pesos (113 USD). Approximately 80% of this figure corresponds to basic management protocol., Conclusion: Exposure to risk fluids in health personnel is frequent and has a high cost. This cost can be reduced by the application of prevention measures to give the healthcare workers a safer environment for their daily practice.

Introduction Dental care has become a challenge for healthcare associated infection prevention programs, since the environment, within other factors, plays an important role in the transmission chain. Materials and Methods An intervention program was designed for the Dental Unit of Hospital Militar de Santiago, between years 2014 and 2015. The program contemplated 3 stages: diagnostic, intervention and evaluation stage. Objective To improve the safety of critical surfaces involved in dental healthcare. Results During the diagnostic stage, the cleaning and disinfection process was found to be deficient. The most contaminated critical surface was the instrument holder unit, then the clean area and lamp handle. The surfaces that significantly reduced their contamination, after the intervention, were the clean area and the instrument carrier unit. Conclusion Training in the processes of cleaning and disinfecting surfaces and dental equipment is one of the cost-effective strategies in preventing healthcare-associated infections (HCAI), with simple and easy-to-apply methods.

Background: Ventilator-associated pneumonia (VAP) is an adverse event that increases morbidity, mortality and costs due to a prolonged stay and requirement of microbiological studies and antimicrobial therapy. There is not recent data of VAP costs in Chile., Aim: To evaluate additional costs in adult patients with VAP compared to controls in a general hospital in the Metropolitan Area., Patients and Methods: Use of the PAHO paired casecontrol protocol for cost evaluation associated to nosocomial infections and estimation of cost in excess per VAP event. Length of stay (LOS) in excess, antimicrobial consumption in daily-defined doses (DDD), and number of microbiological studies were compared between both groups., Results: From 2012 to 2015, 18 patients with VAP events were identified with their respective controls. LOS exceeded 6.1 days on average among patients with VAP respect to controls (p < 0.05). DDD was higher among patients with VAP (difference 11.7 DDD) as well as number of cultures (3.2 higher on average, p < 0.05). Cost in excess per VAP event reached 4,475 USD., Conclusions: In our Centre, VAP events are associated to a higher LOS, antimicrobial consumption and microbiological studies.

Background: There is no consensus definition to distinguish infectious from non-infectious phlebitis associated to peripheral venous catheter., Aims: To evaluate the impact of an intervention program on the rate of infectious (those associated to bacteremia or local purulent discharge) and non-infectious phlebitis (the rest) and identify differential features., Methods: Interventional study developed in three stages: basal measurement, intervention, and evaluation., Results: Ten infectious and 186 non-infectious phlebitis were registered. Infectious phlebitis diminished after intervention (0.2 to 0.04 events per 1,000 bed-days; p = 0.02) but not the rest (2.3 per 1,000 bed-days before and after). Five of 10 patients with infectious phlebitis had bacteremia, one with infectious endocarditis and valve replacement, and other with septic shock and a fatal outcome. None of the patients in the non-infectious group presented complications. Infectious phlebitis appeared later (mean 4.1 versus 2.4 days; p = 0.007) and were associated to fever (40% vs 5.9%, p = 0.004). Non-infectious phlebitis was associated to irritating compounds (OR 6.1; IC95 1.3-29, p < 0.05)., Conclusions: The intervention program demonstrated a favorable impact only on the rate of infectious phlebitis. Distinction appears to be relevant because those of infectious origin are associated with fever, complications or death, respond to an intervention program, and emerge lately.

Background: Infectious complications associated to central venous catheter (CVC) increase morbidity, mortality and costs. Total parenteral nutrition (TPN) is one of the risk factors described for catheter-related bloodstream infection (CR-BSI). The aim of this study was explore if TPN and time of exposition, are risk factors for CR-BSI among patient exposed to this therapy., Patients and Methods: Cohort study of patients with CVC exposed and not exposed to TPN with calculation of the relative risk (RR) for CR-BSI and percentage of CR-BSI according to different times of exposition to TPN. Study encompassed years 2010-2015 and only adult patients were included., Results: During the study period 51 events of CR-BSI were identified, with 27 occurring among those exposed to TPN and 24 among those not exposed. CR-BSI incidence rate was 6.3 in the group with TPN and 1.2 in those without this therapy (RR 5.4; IC 95 3.6-8.2). The percentage of patients with CR-BSI increased in parallel to exposition time (Pearson coefficient +0.91) and the OR increased for expositions ≥ 7 days (OR 2.8; IC 95 1.047.4; p < 0.05)., Conclusions: Exposition to TPN increases the risk to CR-BSI in adult patients with CVC and this risk raise with exposition time.

Background: Peripheral venous vascular catheters (PVC) are devices that are not free of complications, and CDC, Atlanta, recommendations are followed in order to prevent them. However, available information in Chile on this matter is scarce., Objective: To evaluate if management of PVC fulfill safety recommendations in adult patients in a general hospital., Methods: Cross-sectional study evaluating compliance with 4 measures: patch condition, circuit condition, justification of PVC and registration of the device on medical records., Results: We evaluated 102 PVC, and 45.1% met all the measures assessed. Deficiencies were identified in 54.9% and included shortfalls in every one of the 4 topics measured. Compliance among those with iv sets was higher in comparison with those using mechanical valve needleless connectors (2.5 vs 1.9 points in a scale from 0 to 4; p < 0.001). In addition, compliance decreased progressively along time of use (Pearson coefficient -0.4; p < 0.05)., Conclusions: Deficiencies on the safety management of PVC were frequent in clinical practice and worsen with days. Needleless mechanical connectors use is associated with a lower compliance.

The RNA-editing adenosine deaminases (ADARs) catalyze deamination of adenosine to inosine in double stranded structure found in various RNA substrates, including mRNAs. Here we describe the synthesis of a phosphoramidite of 2'-deoxy-2'-mercaptoadenosine and its incorporation into an ADAR substrate. Surprisingly, no deamination product was observed with this substrate indicating replacing the 2'-OH with a 2'-SH at the editing site is highly inhibitory. Modeling of nucleotide binding into the active site suggests the side chain of T375 of human ADAR2 to be in proximity of the 2'-substituent. Mutation of this residue to cysteine caused a greater that 100-fold reduction in deamination rate with the 2'-OH substrate.

Surprisingly facile direct substitution reactions with acetyl-protected 6-bromopurine nucleosides are described. Included in the series of bromonucleosides studied is the guanosine derivative N(2)-2',3',5'-tetraacetyl-6-bromopurine ribonucleoside, the synthesis of which is reported here for the first time. Brominated nucleosides had not previously been considered optimal substrates for S(N)Ar reactions given the general reactivity trend for halogenated aromatic systems (i.e. F > Cl > Br > I). However, even weakly nucleophilic aromatic amines give high yields of the substitution products in polar solvents with these 6-bromopurine nucleosides. For primary aromatic amines, secondary aliphatic amines, and imidazole, reaction takes place only at C6, with no effect on the acetyl-protected ribose. In addition, we report the first synthesis of 3',5'-di-O-acetyl-6-bromopurine-2'-deoxyribonucleoside and its reaction with an arylamine in MeOH in the absence of added metal catalyst. Thus, C6-arylamine derivatives of both adenosine and 2'-deoxyadenosine can be prepared via simple S(N)Ar reactions with the corresponding 6-bromo precursor. We also describe high yielding and C6-selective substitution reactions with 6-bromonucleosides using alcohol and thiol nucleophiles in the presence of added base (DBU). Finally, C6-bromonucleosides are shown to be readily hydrogenated to give purine or 2-aminopurine products in good yield. This work increases the arsenal of reactions and strategies available for the synthesis of nucleoside analogues as potential biochemical tools or new therapeutics.

We report the synthesis of a 5'-DMT-2'-TBDMS-protected phosphoramidite of 6-trifluoromethylpurine ribonucleoside ((TFM)P) and its use in the site-specific incorporation of 6-trifluoromethylpurine into RNA. Properties of (TFM)P-substituted RNA suggest it will be valuable in the study of RNA structure and the binding of RNA-modifying enzymes, particularly the RNA-editing adenosine deaminases. Reaction: see text.