Antidepressant Augmentation versus Switch in Treatment-Resistant Geriatric Depression.

BACKGROUND: The benefits and risks of augmenting or switching antidepressants in older adults with treatment-resistant depression have not been extensively studied. METHODS: We conducted a two-step, open-label trial involving adults 60 years of age or older with treatment-resistant depression. In step 1, patients were randomly assigned in a 1:1:1 ratio to augmentation of existing antidepressant medication with aripiprazole, augmentation with bupropion, or a switch from existing antidepressant medication to bupropion. Patients who did not benefit from or were ineligible for step 1 were randomly assigned in step 2 in a 1:1 ratio to augmentation with lithium or a switch to nortriptyline. Each step lasted approximately 10 weeks. The primary outcome was the change from baseline in psychological well-being, assessed with the National Institutes of Health Toolbox Positive Affect and General Life Satisfaction subscales (population mean, 50; higher scores indicate greater well-being). A secondary outcome was remission of depression. RESULTS: In step 1, a total of 619 patients were enrolled; 211 were assigned to aripiprazole augmentation, 206 to bupropion augmentation, and 202 to a switch to bupropion. Well-being scores improved by 4.83 points, 4.33 points, and 2.04 points, respectively. The difference between the aripiprazole-augmentation group and the switch-to-bupropion group was 2.79 points (95% CI, 0.56 to 5.02; P = 0.014, with a prespecified threshold P value of 0.017); the between-group differences were not significant for aripiprazole augmentation versus bupropion augmentation or for bupropion augmentation versus a switch to bupropion. Remission occurred in 28.9% of patients in the aripiprazole-augmentation group, 28.2% in the bupropion-augmentation group, and 19.3% in the switch-to-bupropion group. The rate of falls was highest with bupropion augmentation. In step 2, a total of 248 patients were enrolled; 127 were assigned to lithium augmentation and 121 to a switch to nortriptyline. Well-being scores improved by 3.17 points and 2.18 points, respectively (difference, 0.99; 95% CI, -1.92 to 3.91). Remission occurred in 18.9% of patients in the lithium-augmentation group and 21.5% in the switch-to-nortriptyline group; rates of falling were similar in the two groups. CONCLUSIONS: In older adults with treatment-resistant depression, augmentation of existing antidepressants with aripiprazole improved well-being significantly more over 10 weeks than a switch to bupropion and was associated with a numerically higher incidence of remission. Among patients in whom augmentation or a switch to bupropion failed, changes in well-being and the occurrence of remission with lithium augmentation or a switch to nortriptyline were similar. (Funded by the Patient-Centered Outcomes Research Institute; OPTIMUM ClinicalTrials.gov number, NCT02960763.).

Enhanced Photocatalytic Activities of Sodium Borohydride-Calcined Magnetic Manganese Ferrite Nanoparticles.

The synthesis, enhancement, and maintenance of magnetite-based catalyst nanoparticles (NPs) are important for photocatalytic activity and recovery rates. We used a sodium borohydride (NaBH4) calcination method to modify MnFe2O4 nanoparticles to optimize their performance in the photocatalytic oxidation of 2,5-hydroxymethylfurfural. The results indicated a 94% increase in photocatalytic efficiency, while magnetic assessments performed using a vibrating sample magnetometer showed an 8.9% improvement in magnetic properties without degradation. These findings show the dual benefits of increased photocatalytic performance with strong magnetic properties, which are important for the application and reusability of photocatalysts. The recycling of these photocatalysts reduces secondary pollution and increases the process cost-effectiveness. These results contribute to the solution of problems with the use of photocatalytic materials.

Safety and efficacy of IV theophylline for regadenoson-associated side effect reversal.

BACKGROUND: Aminophylline injection has been on an intermittent nation-wide shortage due to manufacturing delays leaving a need for an alternative reversal agent for regadenoson-associated side effects. Intravenous theophylline should be a logical acceptable pharmacological alternative; however, data regarding its safety and efficacy as a reversal agent are lacking. METHODS: Utilizing electronic medical records at the University of Colorado hospital, we identified patients ≥ 18 years of age who had a pharmacologic stress test using regadenoson during periods of aminophylline shortage (3/1/2013 to 5/31/2013 and 4/1/2018 to 8/30/2018) in which theophylline was used as an alternative antidote for side effect reversal. Intravenous theophylline was prepared by the inpatient pharmacy to a concentration of 0.8 mg/mL in a total volume of 100 mL D5W. Specific side effects and side effect resolution were evaluated. RESULTS: Of the 122 patients evaluated, theophylline was administered in doses ranging from 40 to 75 mg with the majority receiving 40 mg. Complete resolution of regadenoson side effects occurred in 98 patients with 12 experiencing partial resolution and 1 without resolution. No adverse effects or events were reported. CONCLUSION: Due to limited availability of aminophylline, theophylline may be a safe and effective alternative to reverse regadenoson-associated side effects.

Revealing Photocatalytic Performance of ZnxCd1-xS Nanoparticles Depending on the Irradiation Wavelength.

Photocatalysts are useful for various applications, including the conservation and storage of energy, wastewater treatment, air purification, semiconductors, and production of high-value-added products. Herein, ZnxCd1-xS nanoparticle (NP) photocatalysts with different concentrations of Zn2+ ions (x = 0.0, 0.3, 0.5, or 0.7) were successfully synthesized. The photocatalytic activities of ZnxCd1-xS NPs varied with the irradiation wavelength. X-ray diffraction, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and ultraviolet-visible spectroscopy were used to characterize the surface morphology and electronic properties of the ZnxCd1-xS NPs. In addition, in situ X-ray photoelectron spectroscopy was performed to investigate the effect of the concentration of Zn2+ ions on the irradiation wavelength for photocatalytic activity. Furthermore, wavelength-dependent photocatalytic degradation (PCD) activity of the ZnxCd1-xS NPs was investigated using biomass-derived 2,5-hydroxymethylfurfural (HMF). We observed that the selective oxidation of HMF using ZnxCd1-xS NPs resulted in the formation of 2,5-furandicarboxylic acid via 5-hydroxymethyl-2-furancarboxylic acid or 2,5-diformylfuran. The selective oxidation of HMF was dependent on the irradiation wavelength for PCD. Moreover, the irradiation wavelength for the PCD depended on the concentration of Zn2+ ions in the ZnxCd1-xS NPs.

Performance Promotion of Multipurpose Catalysts Using Increased Oxygen Vacancy Amounts by Charge-Mismatched Doping.

Modulating the oxygen vacancy (V0) in nanostructures has opened a new avenue for efficient catalyst design, facilitating biomass oxidation reactions and electrocatalytic properties. In this study, we have investigated the properties of NiO-based catalysts with varying degrees of V0 achieved through ion doping of the catalyst with cations of different oxidation states (TM3+) or the same valence state (TM2+) as Ni2+ in the NiO matrix. By introducing charge-mismatched dopants, we enhanced the concentration of V0 in the NiO catalyst, resulting in remarkable selectivity (∼50%) for the conversion of 2,5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), as well as a lower overpotential in the oxygen evolution reaction (OER). We believe that charge-mismatched doping offers a novel avenue for optimizing defect engineering in oxide-based catalysts, which can enable more efficient biomass conversion and water splitting. These findings have made a significant contribution to the field of multipurpose catalysis and hold the potential to inspire new catalyst designs that would usher in a more sustainable future.

Enhancement of Sulfur Source-Dependent Zn Vacancies in Different Photocatalytic Performances of ZnIn2S4 Nanoparticles.

This study focuses on the synthesis and investigation of ZnIn2S4 nanoparticle (NP) photocatalysts treated with different sulfur sources, thioacetamide (TAA), or thiourea (TU), to explore their wavelength-dependent photocatalytic activity. The research aims to understand the impact of Zn vacancies present on the surface of ZnIn2S4 NPs. The investigation involves electron spin resonance and in situ X-ray photoelectron spectroscopy to study the photocatalytic activity of ZnIn2S4-TU and ZnIn2S4-TAA NPs, following the characterization of surface morphology and electronic properties using high-resolution transmission electron microscopy and X-ray diffraction. Additionally, the study delves into the wavelength-dependent photocatalytic degradation (PCD) activity of the ZnIn2S4 NPs using 2,5-hydroxymethylfurfural (HMF) across a wide range. Notably, the selective oxidation of HMF using ZnIn2S4-TU NPs resulted in the formation of 2,5-furandicarboxylic acid (FDCA) via 2,5-diformylfuran, with an efficiency exceeding 40% over the broad wavelength range. The research demonstrates that the irradiation wavelength for PCD is influenced by the number of defect structures introduced into the ZnIn2S4 NPs through the sulfur source.

A General Autofluorescence Method to Characterize Polymerization Progress.

An autofluorescence technique to characterize polymerization progress in real time/in line was developed, which functioned in the absence of typical fluorogenic groups on the monomer or polymer. The monomer dicyclopentadiene and polymer polydicyclopentadiene are hydrocarbons that lack traditional functional groups for fluorescence spectroscopy. Here, the autofluorescence of formulations containing this monomer and polymer during ruthenium-catalyzed ring-opening metathesis polymerization (ROMP) was harnessed for reaction monitoring. The methods fluorescence recovery after photobleaching (FRAP) and here-developed fluorescence lifetime recovery after photobleaching (FLRAP) characterized polymerization progress in these native systems-without requiring exogenous fluorophore. (Auto)fluorescence lifetime recovery changes during polymerization correlated linearly to degree of cure, providing a quantitative link with reaction progress. These changing signals also provided relative rates of background polymerization, enabling comparison of 10 different catalyst-inhibitor-stabilized formulations. Multiple-well analysis demonstrated suitability for future high-throughput evaluation of formulations for thermosets. The central concept of the combined autofluorescence and FLRAP/FRAP method may be extendable to monitoring other polymerization reactions previously overlooked for lack of an obvious fluorescence handle.

Selective Oxidation of Biomass Molecules via ZnO Nanoparticles Modified Using Charge Mismatch of the Doped Co ions.

A charge mismatch between transition-metal-ion dopants and metal oxide nanoparticles (MO NPs) within an engineered complex engenders a significant number of oxygen vacancies (VO) on the surface of the MO NP construct. To elucidate in-depth the mechanism of this tendency, Co ions with different charge states (Co3+ and Co2+) were doped into ZnO NPs, and their atomic structural changes were correlated with their photocatalytic efficiency. We ascertained that the increase of the Zn-O bond distances was distinctly affected by Co3+-ion doping, and, subsequently, the number of VO was noticeably increased. We further investigated the mechanistic pathways of the photocatalytic oxidation of 2,5-hydroxymethylfurfural (HMF), which have been widely investigated as biomass derivatives because of their potential use as precursors for the synthesis of sustainable alternatives to petrochemical substances. To identify the reaction products in each oxidation step, selective oxidation products obtained from HMF in the presence of pristine ZnO NPs, Co3+- and Co2+-ion-doped ZnO NPs were evaluated. We confirmed that Co3+-ion-doped ZnO NPs can efficiently and selectively oxidize HMF with a good conversion rate (∼40%) by converting HMF to 2,5-furandicarboxylic acid (FDCA). The present study demonstrates the feasibility of improving the production efficiency of FDCA (an alternative energy material) by using enhanced photocatalytic MO NPs with the help of the charge mismatch between MO and metal-ion dopants.

Ecological Momentary Assessment of Real-World Functional Behaviors in Individuals With Stroke: A Longitudinal Observational Study.

OBJECTIVE: To validate and characterize real-world functional behaviors in individuals after stroke. DESIGN: Longitudinal observational study using ecological momentary assessment (EMA) as a real-time assessment of functional behaviors in natural contexts. Wilcoxon rank-sum tests, Fisher exact tests, and Spearman correlations were used to analyze data. SETTING: Community. PARTICIPANTS: Individuals with mild to moderate stroke (N=212). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Individuals were assessed 5 times daily for 14 days with EMA surveys to determine what, with whom, and where individuals were doing activities and appraise mental, somatic, and cognitive symptoms. Individuals also completed standardized assessments during laboratory visits, including Lawton Instrumental Activities of Daily Living Scale, Activity Card Sort, Patient-Reported Outcome Measurement Information System, and Quality of Life in Neurological Disorders. RESULTS: Most individuals (median age, 60 years; 55% male) were ischemic stroke (90%) and had mild stroke severity (median National Institutes of Health Stroke Scale, 2). A total of 14,140 EMA surveys were analyzed. Individuals were home 78% of the time; primarily participated in passive, unproductive activities (27%), especially watching television and resting; and participated least in physical activities (4%). EMA was sensitive to indicators of poststroke disability; unemployed individuals reported fewer vocational activities but more activities of daily living (ADL) and passive activities than employed counterparts. Users of mobility devices and individuals with cognitive problems spent significantly less time on vocational activities and more on ADL than nonusers and those without cognitive problems. Our data supported the validity of EMA methods in stroke, with small to moderate correlations of EMA with in-laboratory measures of daily functioning (r=-0.30 to 0.35, P<.05) and very large correlations between EMA and in-laboratory measures of symptoms, especially those measuring same constructs (r=-0.64 to 0.79, P<.0001). CONCLUSIONS: Our findings reveal that EMA tracked poststroke functioning precisely. EMA may be beneficial in examining poststroke functional recovery, in monitoring patients for home-based interventions, and for longitudinal research.

Comparison between Nanoparticle Encapsulation and Surface Loading for Lysosomal Enzyme Replacement Therapy.

Poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) enhance the delivery of therapeutic enzymes for replacement therapy of lysosomal storage disorders. Previous studies examined NPs encapsulating or coated with enzymes, but these formulations have never been compared. We examined this using hyaluronidase (HAse), deficient in mucopolysaccharidosis IX, and acid sphingomyelinase (ASM), deficient in types A−B Niemann−Pick disease. Initial screening of size, PDI, ζ potential, and loading resulted in the selection of the Lactel II co-polymer vs. Lactel I or Resomer, and Pluronic F68 surfactant vs. PVA or DMAB. Enzyme input and addition of carrier protein were evaluated, rendering NPs having, e.g., 181 nm diameter, 0.15 PDI, −36 mV ζ potential, and 538 HAse molecules encapsulated per NP. Similar NPs were coated with enzyme, which reduced loading (e.g., 292 HAse molecules/NP). NPs were coated with targeting antibodies (> 122 molecules/NP), lyophilized for storage without alterations, and acceptably stable at physiological conditions. NPs were internalized, trafficked to lysosomes, released active enzyme at lysosomal conditions, and targeted both peripheral organs and the brain after i.v. administration in mice. While both formulations enhanced enzyme delivery compared to free enzyme, encapsulating NPs surpassed coated counterparts (18.4- vs. 4.3-fold enhancement in cells and 6.2- vs. 3-fold enhancement in brains), providing guidance for future applications.

Human Papillomavirus-Associated Sexual Risks Among High School Students in the U.S.: Does Sexual Orientation Play a Role?

We examined the association between sexual orientation and human papillomavirus (HPV)-related risky sexual behaviors among high school students in the U.S. We used the 2015 Youth Risk Behavior Survey, a three-stage cluster sample, nationally representative, cross-sectional study. Participants were sexually active students (Grades 9-12) in public, private, and Catholic schools in 50 states and the District of Columbia (n = 5,958). Sexual orientation dimensions were: sexual self-identity (heterosexual, gay, lesbian, bisexual, and not sure) and sex of sexual contacts. HPV-associated risky sexual risk behaviors selected a priori were early sexual debut (≤ 12 or ≥ 13 years old) and number of lifetime partners (≥ 2 or ≥ 4). Separate multiple logistic regression analyses estimated association between sexual orientation and sex of sexual contacts, and HPV-associated risky sexual behaviors. Among the 5,958 high school students, a quarter had ≥ 4, and two-thirds had ≥ 2 sexual partners. Students who self-identified as bisexual (aOR = 2.43, 99% CI 1.19-4.98) or "not sure" (aOR = 4.56, 99% CI 2.54-8.17) were more likely to have sexual debut before 13 years. Similarly, students whose sexual contacts were adolescent females who had sex with females and males were more likely to have sexual debut before they turned 13 years of age (aOR = 3.46, 99% CI 1.83-6.48), or had ≥ 4 sexual partners (aOR = 2.66, 99% CI 1.74-4.08), or had ≥ 2 sexual partners (aOR = 3.09, 99% CI 1.91-5.00). In conclusion, HPV-associated risky sexual behavior is prevalent among high school students, especially sexual minorities. Interventions tailored to this population could increase HPV vaccine uptake and prevent future HPV-associated cancers and other negative outcomes.

The Effect of Venlafaxine on Electrocardiogram Intervals During Treatment for Depression in Older Adults.

PURPOSE/BACKGROUND: Venlafaxine is a commonly used antidepressant with both serotonergic and noradrenergic activity. There are concerns that it may prolong the corrected QT interval (QTc), and older adults may be at higher risk for this adverse effect, especially at higher dosages of the medication. METHODS/PROCEDURES: In this secondary analysis of a prospective clinical trial, we measured changes in QTc and other electrocardiogram (ECG) parameters in 169 adults 60 years or older with a major depressive disorder treated acutely with venlafaxine extended release up to 300 mg daily. We examined the relationship of venlafaxine dosage and ECG parameters, as well as the relationship between serum levels of venlafaxine and ECG parameters. FINDINGS/RESULTS: Venlafaxine exposure was not associated with an increase in QTc. Heart rate increased with venlafaxine treatment, whereas the PR interval shortened, and QRS width did not change significantly. The QTc change from baseline was not associated with venlafaxine dosages or serum concentrations. Age, sex, cardiovascular comorbidities, and depression remission status did not predict changes in QTc with venlafaxine. IMPLICATIONS/CONCLUSIONS: Venlafaxine treatment did not prolong QTc or other ECG parameters, even in high dosages in older depressed adults. These findings indicate that venlafaxine does not significantly affect cardiac conduction in most older patients.

Experiences of American Older Adults with Pre-existing Depression During the Beginnings of the COVID-19 Pandemic: A Multicity, Mixed-Methods Study.

OBJECTIVE: To determine the effect of the COVID-19 pandemic on the mental health of older adults with pre-existing major depressive disorder (MDD). PARTICIPANTS: Participants were 73 community-living older adults with pre-existing MDD (mean age 69 [SD 6]) in Los Angeles, New York, Pittsburgh, and St Louis. DESIGN AND MEASUREMENTS: During the first 2 months of the pandemic, the authors interviewed participants with a semistructured qualitative interview evaluating access to care, mental health, quality of life, and coping. The authors also assessed depression, anxiety, and suicidality with validated scales and compared scores before and during the pandemic. RESULTS: Five themes from the interviews highlight the experience of older adults with MDD: 1) They are more concerned about the risk of contracting the virus than the risks of isolation. 2) They exhibit resilience to the stress and isolation of physical distancing. 3) Most are not isolated socially, with virtual contact with friends and family. 4) Their quality of life is lower, and they worry their mental health will suffer with continued physical distancing. 5) They are outraged by an inadequate governmental response to the pandemic. Depression, anxiety, and suicidal ideation symptom scores did not differ from scores before the pandemic. CONCLUSION: Most older adults with pre-existing MDD show resilience in the first 2 months of the COVID-19 pandemic but have concerns about the future. Policies and interventions to provide access to medical services and opportunities for social interaction are needed to help to maintain mental health and quality of life as the pandemic continues.

Intravaginal practices and genital human papillomavirus infection among female sex workers in Cambodia.

OBJECTIVES: Intravaginal practices (IVPs) include washing, wiping, or inserting something inside the vagina. This study investigates the associations between IVPs and genital human papillomavirus (HPV) infection. METHODS: We conducted a cross-sectional study of 200 female sex workers aged 18 to 35 years in Phnom Penh, Cambodia. From August to September 2014. Data on sociodemographic characteristics, IVPs, and other behaviors were collected through face-to-face interviews. Self-collected cervicovaginal specimens were tested for 37 HPV genotypes. RESULTS: Multivariable Poisson regression models showed that a lower number of infecting HPV genotypes were associated with intravaginal washing in the past 3 months (incident rate ratios [IRR] = 0.65, 95% confidence interval [CI]: 0.46-0.94) and often performing intravaginal washing shortly after sex (IRR = 0.89, 95% CI: 0.81-0.99). Intravaginal washing before vaginal sex, intravaginal wiping, and intravaginal insertion were not associated with HPV infection. CONCLUSION: These findings challenge the existing view that all types of vaginal cleansing are harmful. Specifically, intravaginal washing shortly after sex (mainly with water) may help prevent HPV infection in female sex workers, who have several partners and thus frequently expose to sources of HPV infection with different genotypes.

Effect of delirium motoric subtypes on administrative documentation of delirium in the surgical intensive care unit.

This study compares the proportions of surgical intensive care unit (ICU) patients with delirium detected using the Confusion Assessment Method for the ICU (CAM-ICU) who received administrative documentation for delirium using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes, stratified by delirium motoric subtypes. This retrospective cohort study was conducted at a surgical ICU from 06/2012 to 05/2013. Delirium was assessed twice daily and was defined as having ≥1 positive CAM-ICU rating. Delirious patients were categorized into hyperactive/mixed and hypoactive subtypes using corresponding Richmond Agitation Sedation Scales. Administrative documentation of delirium was defined as having ≥1 of 32 unique ICD-9-CM codes. Proportions were compared using Pearson's Chi-square test. Of included patients, 40 % (423/1055) were diagnosed with delirium, and 17 % (183/1055) had an ICD-9-CM code for delirium. The sensitivity and specificity of ICD-9-CM codes for delirium were 36 and 95 %. ICD-9-CM codes for delirium were available for 42 % (95 % CI 35-48 %; 105/253) of patients with hyperactive/mixed delirium and 27 % (95 % CI 20-34 %; 46/170) of patients with hypoactive delirium (relative risk = 1.5; 95 % CI 1.2-2.0; p = 0.002). ICD-9-CM codes yielded a low sensitivity for identifying patients with CAM-ICU positive delirium and were more likely to identify hyperactive/mixed delirium compared with hypoactive delirium.

Effect of Chlorhexidine Bathing Every Other Day on Prevention of Hospital-Acquired Infections in the Surgical ICU: A Single-Center, Randomized Controlled Trial.

OBJECTIVE: To test the hypothesis that compared with daily soap and water bathing, 2% chlorhexidine gluconate bathing every other day for up to 28 days decreases the risk of hospital-acquired catheter-associated urinary tract infection, ventilator-associated pneumonia, incisional surgical site infection, and primary bloodstream infection in surgical ICU patients. DESIGN: This was a single-center, pragmatic, randomized trial. Patients and clinicians were aware of treatment-group assignment; investigators who determined outcomes were blinded. SETTING: Twenty-four-bed surgical ICU at a quaternary academic medical center. PATIENTS: Adults admitted to the surgical ICU from July 2012 to May 2013 with an anticipated surgical ICU stay for 48 hours or more were included. INTERVENTIONS: Patients were randomized to bathing with 2% chlorhexidine every other day alternating with soap and water every other day (treatment arm) or to bathing with soap and water daily (control arm). MEASUREMENTS AND MAIN RESULTS: The primary endpoint was a composite outcome of catheter-associated urinary tract infection, ventilator-associated pneumonia, incisional surgical site infection, and primary bloodstream infection. Of 350 patients randomized, 24 were excluded due to prior enrollment in this trial and one withdrew consent. Therefore, 325 were analyzed (164 soap and water versus 161 chlorhexidine). Patients acquired 53 infections. Compared with soap and water bathing, chlorhexidine bathing every other day decreased the risk of acquiring infections (hazard ratio = 0.555; 95% CI, 0.309-0.997; p = 0.049). For patients bathed with soap and water versus chlorhexidine, counts of incident hospital-acquired infections were 14 versus 7 for catheter-associated urinary tract infection, 13 versus 8 for ventilator-associated pneumonia, 6 versus 3 for incisional surgical site infections, and 2 versus 0 for primary bloodstream infection; the effect was consistent across all infections. The absolute risk reduction for acquiring a hospital-acquired infection was 9.0% (95% CI, 1.5-16.4%; p = 0.019). Incidences of adverse skin occurrences were similar (18.9% soap and water vs 18.6% chlorhexidine; p = 0.95). CONCLUSIONS: Compared with soap and water, chlorhexidine bathing every other day decreased the risk of acquiring infections by 44.5% in surgical ICU patients.

Adsorption of Human Plasma Albumin and Fibronectin onto Nanostructured Black Silicon Surfaces.

The protein adsorption of two human plasma proteins-albumin (Alb) and fibronectin (Fn)-onto synthetic nanostructured bactericidal material-black silicon (bSi) surfaces (that contain an array of nanopillars) and silicon wafer (nonstructured) surfaces-was investigated. The adsorption behavior of Alb and Fn onto two types of substrata was studied using a combination of complementary analytical techniques. A two-step Alb adsorption mechanism onto the bSi surface has been proposed. At low bulk concentrations (below 40 µg/mL), the Alb preferentially adsorbed at the base of the nanopillars. At higher bulk concentrations, the Alb adsorbed on the top of the nanopillars. In the case of Fn, the protein preferentially adsorbed on the top of the nanopillars, irrespective of its bulk concentration.

Age-Stratified Treatment Response Rates in Hospitalized Patients with Clostridium difficile Infection Treated with Metronidazole.

Consensus on the optimal treatment of Clostridium difficile infection (CDI) is rapidly changing. Treatment with metronidazole has been associated with increased clinical failure rates; however, the reasons for this are unclear. The purpose of this study was to assess age-related treatment response rates in hospitalized patients with CDI treated with metronidazole. This was a retrospective, multicenter cohort study of hospitalized patients with CDI. Patients were assessed for refractory CDI, defined as persistent diarrhea after 7 days of metronidazole therapy, and stratified by age and clinical characteristics. A total of 242 individuals, aged 60 ± 18 years (Charlson comorbidity index, 3.8 ± 2.4; Horn's index, 1.7 ± 1.0) were included. One hundred twenty-eight patients (53%) had severe CDI. Seventy patients (29%) had refractory CDI, a percentage that increased from 22% to 28% and to 37% for patients aged less than 50 years, for patients from 50 to 70 years, and for patients aged >70 years, respectively (P = 0.05). In multivariate analysis, Horn's index (odds ratio [OR], 2.04; 95% confidence interval [CI], 1.50 to 2.77; P < 0.001), severe CDI (OR, 2.25; 95% CI, 1.15 to 4.41; P = 0.018), and continued use of antibiotics (OR, 2.65; 95% CI, 1.30 to 5.39; P = 0.0072) were identified as significant predictors of refractory CDI. Age was not identified as an independent risk factor for refractory CDI. Therefore, hospitalized elderly patients with CDI treated with metronidazole had increased refractory CDI rates likely due to increased underlying severity of illness, severity of CDI, and concomitant antibiotic use. These results may help identify patients that may benefit from alternative C. difficile treatments other than metronidazole.

Self-organised nanoarchitecture of titanium surfaces influences the attachment of Staphylococcus aureus and Pseudomonas aeruginosa bacteria.

The surface nanotopography and architecture of medical implant devices are important factors that can control the extent of bacterial attachment. The ability to prevent bacterial attachment substantially reduces the possibility of a patient receiving an implant contracting an implant-borne infection. We now demonstrated that two bacterial strains, Staphylococcus aureus and Pseudomonas aeruginosa, exhibited different attachment affinities towards two types of molecularly smooth titanium surfaces each possessing a different nanoarchitecture. It was found that the attachment of S. aureus cells was not restricted on surfaces that had an average roughness (S a) less than 0.5 nm. In contrast, P. aeruginosa cells were found to be unable to colonise surfaces possessing an average roughness below 1 nm, unless sharp nanoprotrusions of approximately 20 nm in size and spaced 35.0 nm apart were present. It is postulated that the enhanced attachment of P. aeruginosa onto the surfaces possessing these nanoprotrusions was facilitated by the ability of the cell membrane to stretch over the tips of the nanoprotrusions as confirmed through computer simulation, together with a concomitant increase in the level of extracellular polymeric substance (EPS) being produced by the bacterial cells.