Two-photon lithography for customized microstructured surfaces and their influence on wettability and bacterial load

BACKGROUND

Device-related bacterial infections account for a large proportion of hospital-acquired infections. The ability of bacteria to form a biofilm as a protective shield usually makes treatment impossible without removal of the implant. Topographic surfaces have attracted considerable attention in studies seeking antibacterial properties without the need for additional antimicrobial substances. As there are still no valid rules for the design of antibacterial microstructured surfaces, a fast, reproducible production technique with good resolution is required to produce test surfaces and to examine their effectiveness with regard to their antibacterial properties.

METHODS

In this work various surfaces, flat and with microcylinders in different dimensions (flat, 1, 3 and 9 μm) with a surface area of 7 × 7 mm were fabricated with a nanoprinter using two-photon lithography and evaluated for their antibiofilm effect. The microstructured surfaces were cultured for 24 h with different strains of Pseudomonas aeruginosa and Staphylococcus aureus to study bacterial attachment to the patterned surfaces. In addition, surface wettability was measured by a static contact angle measurement.

RESULTS

Contact angles increased with cylinder size and thus hydrophobicity. Despite the difference in wettability, Staphylococcus aureus was not affected by the microstructures, while for Pseudomonas aeruginosa the bacterial load increased with the size of the cylinders, and compared to a flat surface, a reduction in bacteria was observed for one strain on the smallest cylinders.

CONCLUSIONS

Two-photon lithography allowed rapid and flexible production of microcylinders of different sizes, which affected surface wettability and bacterial load, however, depending on bacterial type and strain.

Which parameters influence cognitive, psychiatric and long-term seizure outcome in mesial temporal lobe epilepsy after selective amygdalohippocampectomy?

BACKGROUND

We aimed to analyze potentially prognostic factors which could have influence on postoperative seizure, neuropsychological and psychiatric outcome in a cohort of patients with mesial temporal lobe epilepsy (MTLE) due to hippocampal sclerosis (HS) after selective amygdalohippocampectomy (SAHE) via transsylvian approach.

METHODS

Clinical variables of 171 patients with drug-resistant MTLE with HS (88 females) who underwent SAHE between 1994 and 2019 were evaluated using univariable and multivariable logistic regression models, to investigate which of the explanatory parameters can best predict the outcome.

RESULTS

At the last available follow-up visit 12.3 ± 6.3 years after surgery 114 patients (67.9%) were seizure-free. Left hemispheric MTLE was associated with worse postoperative seizure outcome at first year after surgery (OR = 0.54, p = 0.01), female sex-with seizure recurrence at years 2 (OR = 0.52, p = 0.01) and 5 (OR = 0.53, p = 0.025) and higher number of preoperative antiseizure medication trials-with seizure recurrence at year 2 (OR = 0.77, p = 0.0064), whereas patients without history of traumatic brain injury had better postoperative seizure outcome at first year (OR = 2.08, p = 0.0091). All predictors lost their predictive value in long-term course. HS types had no prognostic influence on outcome. Patients operated on right side performed better in verbal memory compared to left (VLMT 1-5 p < 0.001, VLMT 7 p = 0.001). Depression occurred less frequently in seizure-free patients compared to non-seizure-free patients (BDI-II Z = - 2.341, p = 0.019).

CONCLUSIONS

SAHE gives an improved chance of achieving good postoperative seizure, psychiatric and neuropsychological outcome in patients with in MTLE due to HS. Predictors of short-term outcome don't predict long-term outcome.

Defects in microvillus crosslinking sensitize to colitis and inflammatory bowel disease

Intestinal epithelial cells are covered by the brush border, which consists of densely packed microvilli. The Intermicrovillar Adhesion Complex (IMAC) links the microvilli and is required for proper brush border organization. Whether microvillus crosslinking is involved in the intestinal barrier function or colitis is currently unknown. We investigate the role of microvillus crosslinking in colitis in mice with deletion of the IMAC component CDHR5. Electron microscopy shows pronounced brush border defects in CDHR5-deficient mice. The defects result in severe mucosal damage after exposure to the colitis-inducing agent DSS. DSS increases the permeability of the mucus layer and brings bacteria in direct contact with the disorganized brush border of CDHR5-deficient mice. This correlates with bacterial invasion into the epithelial cell layer which precedes epithelial apoptosis and inflammation. Single-cell RNA sequencing data of patients with ulcerative colitis reveals downregulation of CDHR5 in enterocytes of diseased areas. Our results provide experimental evidence that a combination of microvillus crosslinking defects with increased permeability of the mucus layer sensitizes to inflammatory bowel disease.

A global perspective on bacterial diversity in the terrestrial deep subsurface

While recent efforts to catalogue Earth's microbial diversity have focused upon surface and marine habitats, 12-20 % of Earth's biomass is suggested to exist in the terrestrial deep subsurface, compared to ~1.8 % in the deep subseafloor. Metagenomic studies of the terrestrial deep subsurface have yielded a trove of divergent and functionally important microbiomes from a range of localities. However, a wider perspective of microbial diversity and its relationship to environmental conditions within the terrestrial deep subsurface is still required. Our meta-analysis reveals that terrestrial deep subsurface microbiota are dominated by Betaproteobacteria, Gammaproteobacteria and Firmicutes, probably as a function of the diverse metabolic strategies of these taxa. Evidence was also found for a common small consortium of prevalent Betaproteobacteria and Gammaproteobacteria operational taxonomic units across the localities. This implies a core terrestrial deep subsurface community, irrespective of aquifer lithology, depth and other variables, that may play an important role in colonizing and sustaining microbial habitats in the deep terrestrial subsurface. An in silico contamination-aware approach to analysing this dataset underscores the importance of downstream methods for assuring that robust conclusions can be reached from deep subsurface-derived sequencing data. Understanding the global panorama of microbial diversity and ecological dynamics in the deep terrestrial subsurface provides a first step towards understanding the role of microbes in global subsurface element and nutrient cycling.

Cognitive impairment and low health literacy are associated with poor health outcomes in patients with heart failure

Background

Cognitive impairment and low health literacy are prevalent in patients with heart failure (HF). Low health literacy is associated with poor health outcomes, such as frequent re-hospitalizations and increased mortality. Little is known about the relationships among cognitive impairment, health literacy, and health outcomes (HF rehospitalization and cardiac death).

Objective

To explore the associations among cognitive impairment, health literacy, and cardiac event-free survival in patients with HF.

Methods

This was a longitudinal study of 614 rural patients with HF (male 59%, age 66±13 NYHA class III/IV: 35%). Cognitive function was measured using the Mini-Cog test. Health literacy was measured by the Short Test of Functional Health Literacy in Adults. HF hospitalizations and cardiac mortality were followed at least 2 years and obtained by patient interview, medical record review, and death certificate review. Chi-squares, t-tests, ANOVA, Kaplan-Meier with log rank tests, logistic and Cox regressions were used for data analysis.

Results

Two hundred and seven patients (34%) had cognitive impairment. Compared to those without cognitive impairment, patients with cognitive impairment were 2.77 times more likely to have low health literacy (P&lt;0.001). Patients were divided into 4 groups based on cognitive impairment or not and adequate/low health literacy: (1) No cognitive impairment with adequate health literacy; (2) cognitive impairment with adequate health literacy; (3) no cognitive impairment with low health literacy; and (4) cognitive impairment with low health literacy. Both cognitive impairment and health literacy independently predicted cardiac event-free survival. Cardiac event-free survival was worst in those with both cognitive impairment and low health literacy compared to patients in any of the other three groups. Patients with cognitive impairment and low health literacy had 3.5 times higher risk of a cardiac event compared to those without cognitive impairment or low health literacy (P&lt;0.001, Figure). Age, income, angiotensin converting enzyme inhibitor use, beta-blocker use, New York Heart Association functional class, left ventricular ejection fraction, BNP level were significantly different among the four cognitive and literacy groups.

Conclusion

Patients with cognitive impairment with low health literacy were at high risk of experiencing a cardiac event. Interventions need to be developed to target high risk patients with cognitive impairment and low health literacy, such as older, low-income patients, to alleviate poor outcomes in patients with HF.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NIH/NHLBI

Bright light therapy as a non-pharmacological treatment option for multiple sclerosis-related fatigue: A randomized sham-controlled trial

Background

Fatigue is a common symptom in people with multiple sclerosis (pwMS) that significantly impairs quality of life. Bright light therapy may be a cheap treatment option with little to no adverse events.

Objectives

To evaluate the effectiveness of bright light therapy as a treatment option for MS-related fatigue.

Methods

This was randomized sham-controlled trial including 26 pwMS with a Fatigue Severity Scale (FSS) Score ≥36. Participants were assigned to receive either bright white light therapy (n = 13) or dim red light (sham-intervention; n = 13). Participants used the respective intervention for 30 min each morning for two weeks, followed by a two-week washout period. The primary endpoint was the difference in FSS scores following light treatment as calculated by analysis of covariance.

Results

There was no significant difference in FSS (F(1,23) = 2.39, p = .136, partial ⴄ² = .094). However, FSS scores generally improved over the course of the study in a clinically relevant manner.

Conclusion

Bright light therapy decreased FSS scores over the course of this study. However, this effect was not significant in comparison to a sham intervention.

Effects of location, classroom orientation, and air change rate on potential aerosol exposure: an experimental and computational study

This study examined the dispersion of potentially infectious aerosols in classrooms by means of both a CO₂ tracer gas, and multizone contaminant transport modeling. A total of 20 tests were conducted in three different university classrooms at multiple air change rates (4.4-9.7/h), each with two different room orientations: one with the tracer gas released from six student desks toward the air return, and one with the same tracer gas released away from it. Resulting tracer concentrations were measured by 19 different monitors arrayed throughout the room. Steady-state, mean tracer gas concentrations were calculated in six instructor zones (A-F) around the periphery of the room, with the results normalized by the concentration at the return, which was assumed to be representative of the well-mixed volume of the room. Across all classrooms, zones farthest from the return (C, D) had the lowest mean normalized concentrations (0.75), while those closest to the return (A, F) had the highest (0.95). This effect was consistent across room orientations (release both toward and away from the return), and air change rates. In addition, all zones around the periphery of the room had a significantly lower concentration than those adjacent to the sources. Increasing the ventilation rate reduced tracer gas concentrations significantly. Similar trends were observed via a novel approach to CONTAM modeling of the same rooms. These results indicate that informed selection of teaching location within the classroom could reduce instructor exposure.

Imaging visuospatial memory in temporal lobe epilepsy—Results of an fMRI study

Purpose

Impairment of cognitive functions is commonly observed in temporal lobe epilepsy (TLE). The aim of this study was to assess visuospatial memory functions and memory-related networks using an adapted version of Roland’s Hometown Walking (RHWT) functional MRI (fMRI) task in patients with TLE.

Methods

We used fMRI to study activation patterns based on a visuospatial memory paradigm in 32 TLE patients (9 right; 23 left) and also within subgroups of lesional and non-lesional TLE. To test for performance, a correlational analysis of fMRI activation patterns and out-of-scanner neuropsychological visuospatial memory testing was performed. Additionally, we assessed memory-related networks using functional connectivity (FC).

Results

Greater contralateral than ipsilateral mesiotemporal (parahippocampal gyrus/hippocampus) activation was observed in left (n = 23)/right (n = 9) TLE. In lesional left TLE (n = 17), significant activations were seen in right more than left mesiotemporal areas (parahippocampal gyrus), while non-lesional left TLE patients (n = 6) showed significant bilateral (left>right) activations in mesiotemporal structures (parahippocampal gyrus). In left TLE, visuospatial cognitive testing correlated with fMRI activations in left (parahippocampal gyrus) and right mesiotemporal structures (hippocampus), characterized by greater fMRI activation being associated with better memory scores. In right TLE, higher scores in visuospatial memory testing were associated with greater fMRI activations in left and right insular regions. FC patterns of memory-related networks differ in right and left TLE.

Conclusion

While TLE in general leads to asymmetrical mesiotemporal activation, lesion-induced and non-lesional TLE patients reveal different memory fMRI activation patterns. In right TLE, insular regions try to compensate for impaired right mesiotemporal structures during the performance of visuospatial tasks. Underlying functional visuospatial memory networks differ in right and left TLE.

Effects of metformin on human bone-derived mesenchymal stromal cell-breast cancer cell line interactions

Metformin is used to treat patients with type 2 diabetes mellitus and was found to lower the incidence of cancer. Bone metastasis is a common impairment associated with advanced breast cancer. The present study investigated the effects of metformin on human bone-derived mesenchymal stromal cells (BM-MSC)—breast cancer cell line interactions. BM-MSCs grown from box chisels were tested for growth-stimulating and migration-controlling activity on four breast cancer cell lines either untreated or after pretreatment with metformin. Growth stimulation was tested in MTT tests and migration in scratch assays. Furthermore, the expression of adipokines of BM-MSCs in response to metformin was assessed using Western blot arrays. Compared to breast cancer cell lines (3.6 ± 1.4% reduction of proliferation), 500 µM metformin significantly inhibited the proliferation of BM-MSC lines (mean 12.3 ± 2.2 reduction). Pretreatment of BM-MSCs with metformin showed variable effects of the resulting conditioned media (CM) on breast cancer cell lines depending on the specific BM-MSC—cancer line combination. Metformin significantly reduced the migration of breast cancer cell lines MDA-MB-231 and MDA-MB-436 in response to CM of drug-pretreated BM-MSCs. Assessment of metformin-induced alterations in the expression of adipokines by BM-MSC CM indicated increased osteogenic signaling and possibly impairment of metastasis. In conclusion, the anticancer activities of metformin are the result of a range of direct and indirect mechanisms that lower tumor proliferation and progression. A lower metformin-induced protumor activity of BM-MSCs in the bone microenvironment seem to contribute to the positive effects of the drug in selected breast cancer patients.

Mucosal Biofilms Are an Endoscopic Feature of Irritable Bowel Syndrome and Ulcerative Colitis

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) and inflammatory bowel diseases result in a substantial reduction in quality of life and a considerable socioeconomic impact. In IBS, diagnosis and treatment options are limited, but evidence for involvement of the gut microbiome in disease pathophysiology is emerging. Here we analyzed the prevalence of endoscopically visible mucosal biofilms in gastrointestinal disease and associated changes in microbiome composition and metabolism.

METHODS

The presence of mucosal biofilms was assessed in 1426 patients at 2 European university-based endoscopy centers. One-hundred and seventeen patients were selected for in-depth molecular and microscopic analysis using 16S ribosomal RNA gene amplicon-sequencing of colonic biopsies and fecal samples, confocal microscopy with deep learning-based image analysis, scanning electron microscopy, metabolomics, and in vitro biofilm formation assays.

RESULTS

Biofilms were present in 57% of patients with IBS and 34% of patients with ulcerative colitis compared with 6% of controls (P < .001). These yellow-green adherent layers of the ileum and right-sided colon were microscopically confirmed to be dense bacterial biofilms. 16S-sequencing links the presence of biofilms to a dysbiotic gut microbiome, including overgrowth of Escherichia coli and Ruminococcus gnavus. R. gnavus isolates cultivated from patient biofilms also formed biofilms in vitro. Metabolomic analysis found an accumulation of bile acids within biofilms that correlated with fecal bile acid excretion, linking this phenotype with a mechanism of diarrhea.

CONCLUSIONS

The presence of mucosal biofilms is an endoscopic feature in a subgroup of IBS and ulcerative colitis with disrupted bile acid metabolism and bacterial dysbiosis. They provide novel insight into the pathophysiology of IBS and ulcerative colitis, illustrating that biofilm can be seen as a tipping point in the development of dysbiosis and disease.

The effectiveness of surface disinfectants and a micellic H2O2 based water disinfectant on Candida auris

BACKGROUND

As infection control faces new challenges from emerging, multidrug resistant strains of the yeast Candida auris, this study was conducted in order to examine the efficacy of hospital surface disinfectants and a new water disinfectant against C. auris biofilm forms.

METHODS

We tested four reference strains of C. auris (NCPF8971, NCPF8977, NCPF8984, DSM21092) and one C. albicans strain (ATCC10231) against disinfectants based on ethanol (ETH), quaternary ammonium (QAC), a combination of glutaraldehyde, quaternary ammonium and surfactant (ALD) and potassium peroxymonosulfate (PP) as well as 3.4% H₂O₂ and 4.25% H₂O₂ alone. In addition, a micellic-based formulation containing 17% v/v hydrogene peroxide disinfectant (mH₂O₂) was tested. The efficacy of the disinfectants was measured in a 96-well plate using tetrazolium salt reduction (XTT) and the log₁₀ reduction assay.

RESULTS

ETH and QAC displayed in clinically recommended concentrations more than 5log₁₀ reduction and more than 80% XTT activity reduction for all of the Candida biofilms and planktonic cells. Only biofilms of C. auris NCPF8984 were additionally sensitive to all remaining disinfectants. All tested C. auris biofilms were sensitive to PP disinfectant and showed more than 5log₁₀ reduction. However, the XTT assay showed a reduction of less than 80% for the PP disinfectant, indicating the presence of active but non-culturable cells. The 25% mH₂O₂ (corresponding to 4.25% H₂O₂) killed Candida biofilms after 1 minute.

Classroom aerosol dispersion: desk spacing and divider impacts

A study of aerosol dispersion was conducted in a university classroom using a CO₂ tracer gas emitted from three source locations in a steady release, one source location per test. The tracer gas emitted from the single source location represented the potentially infectious aerosol droplets emitted from a single student and was thus a way to examine the influence of one sick student on the rest of the class. Two parameters were adjusted during the testing-the spacing of the desks, which included a spread and compressed configuration, and the inclusion of three-sided clear dividers attached to the student desk surfaces. Tracer dispersion was measured through the use of monitors in 13 locations within the classroom, with eight monitors representing seated student locations, four monitors representing a standing instructor along the classroom front, and one monitor at the return vent in the ceiling. As expected, spacing strongly influenced concentration levels at desks adjacent to the source location. The use of dividers reduced overall student and instructor location tracer concentrations when compared to desks without dividers in most cases. Finally, the influence of air change differences on the results was noted with consistent trends. The experimental construct provides a systematic means for classroom testing that may be broadly applicable to various configurations of classrooms beyond the one tested.

7500 steps per day is associated with lower cardiovascular risk in rural residents with a high prevalence of sedentary lifestyle

Funding Acknowledgements

Type of funding sources: None.

Introduction

Sedentary lifestyle is one of the modifiable risk factors that account for the high prevalence of cardiovascular diseases (CVD) in the rural areas.1,2 Daily step counting, using wearable devices, is increasingly used to monitor physical activity levels in interventions targeting CVD risk reduction in the rural areas.3,4 However, there is a lack of evidence to support a daily step count threshold that may reduce CVD risk among rural residents. The purpose of this study was to examine the relationship between daily step count cut-points and CVD risk.

Methods

This secondary analysis included 312 adults living in the rural areas in the southern United States. Daily step counts from pedometers were collected for 14 consecutive days. Established cut-points were used to categorize participants into groups based on mean daily step count as sedentary (≤ 5000 steps/day), less active (5000 -7499 steps/per), and physically active (≥7500 steps/day).5-7 CVD risk was measured with the Framingham risk score. Generalized additive models were used to examine differences among the 3 activity groups in Framingham risk score, controlling for educational level, perceived physical health status, depressive, marital status, and years of residence in a rural county.

Results

Among the participants (75% female, mean age 50.1 (±13.6) years), 40.7% were sedentary, 35.2% were less active, and 24.0% were physically active. The average Framingham risk score was 11.2% (±9.4%). Framingham risk scores were 1.7% lower in the less active compared to the sedentary group, but the effect was not significant (p &lt;  .11), and 2.6% lower in the physically active compared to the sedentary group (p &lt; .04). The model accounted for 22% of the variation in Framingham risk scores.

Conclusion

These findings indicate that rural residents who averaged 7500 steps or more per day had lower CVD risk, and the difference is clinically significant.

Race matters: cardiovascular disease risk in male US prisoners

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NIH/National Institute of Nursing Research, 1RC2NR011948

Introduction

Approximately 10% of the 2.2 million prisoners in the US have a diagnosis of cardiovascular disease (CVD) and in 2016, 28% of all deaths in custody were attributable to CVD. Black race, inadequate health literacy, and poor perceived control are predictors of increased cardiovascular disease (CVD) risk, which are prevalent in prisoners. However, little is known about the relationships among race, health literacy, and perceived control in CVD risk for male prisoners.

Objective

The purpose of this study was to explore the relationships among race, health literacy, perceived control, and CVD risk while controlling for well-known risk factors (education, partner status, and body mass index) in male prisoners.

Methods

We used baseline data from 349 male prisoners in a biobehavioral CVD risk reduction intervention. Health literacy was measured using the Newest Vital Sign and perceived control by the Control Attitudes Scale- Revised. CVD risk was quantified with the Framingham Risk Score (FRS). Three indirect effects of race on CVD risk were examined using serial mediation model with two sequential mediators (i.e., health literacy and perceived control) and 95% confidence intervals from 5000 bootstrap samples.

Results

Of the participants (mean age = 36 + 10 years), 64.2% were white and 35.8% were black. Mean education level was 12 years and most (85.8%) were not married or partnered. Mean BMI was 28.3 + 5.0. Mean FRS was 6.63 + 4.90, indicating risk percentages of 2.3 to 13.3% over the next ten years. Black prisoners were younger (35 + 9 versus 37 + 10, p = .047) and had lower levels of health literacy (3.84 + 1.90 versus 4.69 + 1.63, p &lt; .001) than white prisoners. No statistically significant differences in perceived control, education, partner status, or body mass index were noted between races. All three indirect effects of race on CVD were significant while the direct effect of race was not. Compared to white prisoners, black prisoners had higher levels of CVD risk through health literacy (a1b1 = .3571, 95% CI [.0948, .7162]) and lower levels of CVD risk through perceived control (a2b2 = -.1855, 95% CI [-.4388, -.0077]). Black prisoners had higher levels of CVD risk through health literacy influenced by perceived control (a1b2d21 = .0627, 95% CI [.0028, .1409]) indicating that despite the protective effect of higher levels of perceived control in black prisoners, CVD risk remained higher compared to their white counterparts.

Conclusion

Future CVD risk reduction interventions in prisoners of all races, but specifically black male prisoners, should include goals of improving health literacy and perceived control in addition to the traditional modifiable risk factors often included in biobehavioral interventions.

How COVID-19 related psycho-social stressors affect longevity

Introduction

Before the COVID-19 pandemic, the literature on psychosocial stressors and psycho-social protective factors already clearly indicated that the two were linked in a multitude of ways to longevity. These ways include 1) directly through increased risk in suicides with respect to psycho-social stress or lack of connectivity 2) increased risk for psychopathologies such as depression, post-traumatic stress disorder and others, which in turn can decrease longevity in indirectly, and 3) a worse/healthier lifestyle that may be associated through decreased/improved social connectivity. With the advent of the COVID-19 pandemic, the ways in which these psychosocial factors could be impacted by policy came into focus. Attempting to quantify the potential future impact of such policies on longevity through psycho-social changes appeared necessary to allow better guidance of policy making. Objective: This presentation aims to leverage the experience gained from making a projection of the impact of pandemic mitigation strategies on longevity in the early advent of the COVID-19 pandemic.

Results

The authors model indicated the high need for measures that are protective of the general populations’ psychosocial health in the face of a pandemic and associated mitigation strategies. Discussion: This presentation will discuss issues concerning quantifications of the impact of COVID-19 related policy on psychosocial health. The assumptions necessary to arrive at projective models may be at odds with parts of the current culture in the field. The presentation will discuss potential strategies in order for the scientific community to be better prepared for similar events in the future.

Disclosure

No significant relationships.

Using a Sweating Residuum/socket Interface Simulator for the Evaluation of Sweat Management Liners in Lower Limb Prosthetics

BACKGROUND

Lab-based simulators can help to reduce variability in prosthetics research. However, they have not yet been used to investigate the effects of sweating at the residuum-liner interface. This work sought to create and validate a simulator to replicate the mechanics of residual limb perspiration. The developed apparatus was used to assess the effects of perspiration and different liner designs.

METHODOLOGY

By scanning a cast, an artificial residuum was manufactured using a 3D-printed, transtibial bone model encased in silicone, moulded with pores. The pores allowed water to emit from the residuum surface, simulating sweating. Dry and sweating cyclic tests were performed by applying compressive and tensile loading, while measuring the displacement of the residuum relative to the socket. Tests were conducted using standard and perforated liners.

FINDINGS

Although maximum displacement varied between test setups, its variance was low (coefficient of variation <1%) and consistent between dry tests. For unperforated liners, sweating increased the standard deviation of maximum displacement approximately threefold (0.04mm v 0.12mm, p<0.001). However, with the perforated liner, sweating had little effect on standard deviation compared to dry tests (0.04mm v 0.04mm, p=0.497).

CONCLUSIONS

The test apparatus was effective at simulating the effect of perspiration at the residual limb. Moisture at the skin-liner interface can lead to inconsistent mechanics. Perforated liners help to remove sweat from the skin-liner interface, thereby mitigating these effects.

Using Perforated Liners to Combat the Detrimental Effects of Excessive Sweating in Lower Limb Prosthesis Users

BACKGROUND

Excessive sweating of the residual limb has a substantial effect on the daily activities of people with lower limb amputation. Prosthetic liners offer protection and comfort to sensitive areas but often exacerbate perspiration. They act as insulators, trapping sweat on the skin's surface to the detriment of skin health. Recently, liners with perforations have been developed, allowing the moisture to escape. The goal of this study was to assess the impact of such liners.

METHODS

A sample group of 13 patients with unilateral transtibial amputation, who wore a perforated liner (PL) as part of their current prescription, was compared to 20 control patients who wore non-perforated liners (NPL). During their routine appointments, they completed a survey of scientifically validated outcome measures relating to their limb health, pain and the impact on daily life over a 12-month period.

RESULTS

Patients using the PL had healthier residual limbs, reporting higher scores on questions relating to limb health, experiencing fewer skin issues (p<0.001) and estimating a 61.8% lower rating in perceived sweat (p=0.004). Perhaps consequentially, there was a lower incidence of residual (p=0.012) and phantom (p=0.001) limb pain when compared to the control group. The prevalence of individual issues affecting the residual limbs of PL users was also lower. Of the issues that remained, only 23% were attributed to sweating in PL users, compared to 49% for the NPL group (p=0.066). PL users missed fewer days of work in the year (2.4 vs 11.6, p=0.267) and were also limited on fewer days (1.4 vs 75.4, p=0.009).

CONCLUSION

The use of perforated liners shows much promise within prosthetic care, significantly improving the health of the residual limb. The observed effects on perceived sweat reduction, residual skin health, pain levels and patient limitation suggest that perforated liners are highly beneficial to patients.

Language network reorganization before and after temporal lobe epilepsy surgery

OBJECTIVE

Epilepsy surgery is the recommended treatment option for patients with drug-resistant temporal lobe epilepsy (TLE). This method offers a good chance of seizure freedom but carries a considerable risk of postoperative language impairment. The extremely variable neurocognitive profiles in surgical epilepsy patients cannot be fully explained by extent of resection, fiber integrity, or current task-based functional MRI (fMRI). In this study, the authors aimed to investigate pathology- and surgery-triggered language organization in TLE by using fMRI activation and network analysis as well as considering structural and neuropsychological measures.

METHODS

Twenty-eight patients with unilateral TLE (16 right, 12 left) underwent T1-weighted imaging, diffusion tensor imaging, and task-based language fMRI pre- and postoperatively (n = 15 anterior temporal lobectomy, n = 11 selective amygdalohippocampectomy, n = 2 focal resection). Twenty-two healthy subjects served as the control cohort. Functional connectivity, activation maps, and laterality indices for language dominance were analyzed from fMRI data. Postoperative fractional anisotropy values of 7 major tracts were calculated. Naming, semantic, and phonematic verbal fluency scores before and after surgery were correlated with imaging parameters.

RESULTS

fMRI network analysis revealed widespread, bihemispheric alterations in language architecture that were not captured by activation analysis. These network changes were found preoperatively and proceeded after surgery with characteristic patterns in the left and right TLEs. Ipsilesional fronto-temporal connectivity decreased in both left and right TLE. In left TLE specifically, preoperative atypical language dominance predicted better postoperative verbal fluency and naming function. In right TLE, left frontal language dominance correlated with good semantic verbal fluency before and after surgery, and left fronto-temporal language laterality predicted good naming outcome. Ongoing seizures after surgery (Engel classes ID-IV) were associated with naming deterioration irrespective of seizure side. Functional findings were not explained by the extent of resection or integrity of major white matter tracts.

CONCLUSIONS

Functional connectivity analysis contributes unique insight into bihemispheric remodeling processes of language networks after epilepsy surgery, with characteristic findings in left and right TLE. Presurgical contralateral language recruitment is associated with better postsurgical language outcome in left and right TLE.

Preparation and antibiofilm studies of curcumin loaded chitosan nanoparticles against polymicrobial biofilms of Candida albicans and Staphylococcus aureus

Polymicrobial biofilms related infections are an important clinical problem with classical antibiotics being not sufficient in therapy. Here, curcumin (Cur) was loaded on positively charged chitosan nanoparticles (CSNP). The antibiofilm activities against mono- and polymicrobial biofilms of Candida albicans and Staphylococcus aureus were evaluated. The average diameter of CSNP-Cur was 134.37 ± 1.99 nm and its surface charge was +18.10 ± 0.82 mV. Cur released from NPs was slower at pH 7.4 than at pH 5.4. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were used to observe biofilm architecture and live/dead organisms within biofilm on medical silicone surface. CSNP-Cur exhibited excellent antibiofilm activity against planktonic bacteria or fungi, mono- and polymicrobial biofilm formations and preformed biofilms. SEM and CLSM showed that CSNP-Cur was able to reduce biofilm thickness as well as kill microbial cells embedded in biofilm on silicone surfaces.

The Influence of Hydraulic Ankles and Microprocessor-control on the Biomechanics of Trans-tibial Amputees During Quiet Standing on a 5° Slope

BACKGROUND

Lower limb amputees have a high incidence of comorbidities, such as osteoarthritis, which are believed to be caused by kinetic asymmetries. A lack of prosthetic adaptation to different terrains requires kinematic compensations, which may influence these asymmetries.

METHOD

Six SIGAM grade E-F trans-tibial amputees (one bilateral) wore motion capture markers while standing on force plates, facing down a 5° slope. The participants were tested under three prosthetic conditions; a fixed attachment foot (FIX), a hydraulic ankle (HYD) and a microprocessor foot with a 'standing support' mode (MPF). The resultant ground reaction force (GRF) and support moment for prosthetic and sound limbs were chosen as outcome measures. These were compared between prosthetic conditions and to previously captured able-bodied control data.

RESULTS

The distribution of GRF between sound and prosthetic limbs was not significantly affected by foot type. However, the MPF condition required fewer kinematic compensations, leading to a reduction in sound side support moment of 59% (p=0.001) and prosthetic side support moment of 43% (p=0.02) compared to FIX. For the bilateral participant, only the MPF positioned the GRF vector anterior to the knees, reducing the demand on the residual joints to maintain posture.

CONCLUSIONS

For trans-tibial amputees, loading on lower limb joints is affected by prosthetic foot technology, due to the kinematic compensations required for slope adaptation. MPFs with 'standing support' might be considered reasonable and necessary for bilateral amputees, or amputees with stability problems due to the reduced biomechanical compensations evident.

Lesion-Specific Language Network Alterations in Temporal Lobe Epilepsy

BACKGROUND AND PURPOSE

Temporal lobe epilepsy, structural or nonlesional, may negatively affect language function. However, little is known about the lesion-specific influence on language networks. We hypothesized that different epileptogenic lesions are related to distinct alterations in the functional language connectome detected by fMRI.

MATERIALS AND METHODS

One hundred one patients with epilepsy due to mesiotemporal sclerosis (21 left, 22 right), low-grade mesiotemporal tumors (12 left), or nonlesional temporal lobe epilepsy (22 left, 24 right) and 22 healthy subjects performed 3T task-based language fMRI. Task-based activation maps (laterality indices) and functional connectivity analysis (global and connectivity strengths between language areas) were correlated with language scores.

RESULTS

Laterality indices based on fMRI activation maps failed to discriminate among patient groups. Functional connectivity analysis revealed the most extended language network alterations in left mesiotemporal sclerosis (involving the left temporal pole, left inferior frontal gyrus, and bilateral premotor areas). The other patient groups showed less extended but also predominantly ipsilesional network changes compared with healthy controls. Left-to-right hippocampal connectivity strength correlated positively with naming function (P = .01), and connectivity strength between the left Wernicke area and the left hippocampus was linked to verbal fluency scores (P = .01) across all groups.

CONCLUSIONS

Different pathologies underlying temporal lobe epilepsy are related to distinct alterations of the functional language connectome visualized by fMRI functional connectivity analysis. Network analysis allows new insights into language organization and provides possible imaging biomarkers for language function. These imaging findings emphasize the importance of a personalized treatment strategy in patients with epilepsy.

1107Reduction of cardiovascular disease risk factors in rural, medically under-served, socioeconomically distressed, high-risk individuals: a randomized controlled trial

Background

People in rural, socioeconomically distressed areas of the world suffer from marked cardiovascular disease (CVD) disparities. Despite the CVD disparities seen in rural, distressed areas, efforts directed toward CVD risk reduction and prevention are limited. We conducted a randomized, controlled trial to determine the effect of an individualized, culturally appropriate, self-care CVD risk reduction intervention (HeartHealth) compared to referral of patients to a primary care provider for usual care on the following CVD risk factors: tobacco use, blood pressure, lipid profile, body mass index, depressive symptoms, and physical activity levels.

Methods

The study protocol and intervention were developed with a community advisory board of lay community members, business owners, local government officials, church leaders, and healthcare providers. We enrolled 355 individuals living in Appalachia with two or more CVD risk factors. The intervention was delivered in person to groups of 10 or fewer individuals over 12 weeks. In the first session, participants chose their CVD risk reduction goals. HeartHealth was designed to provide participants with self-care skills targeting CVD risk reduction while reducing barriers to risk reduction found in austere rural environments. The targeted CVD risk factors were measured at baseline and 4 and 12 months post-intervention. Repeated measures data were analyzed with mixed models.

Results

More individuals in the intervention group compared to the control group met their lifestyle change goal (50% vs 16%, p<0.001). The intervention produced a positive impact on systolic blood pressure (p=0.002, time X group effect), diastolic blood pressure (p=0.001, time x group), total cholesterol (p=0.026, time x group), high density lipoprotein (p=0.002, time x group), body mass index (p=0.017, time x group), smoking status (p=0.01), depressive symptoms (p=0.01, time x group), and steps per day (p=0.001, time x group). Compared to the control group, improvement was seen at 4 months in these risk factors and the positive changes were maintained through 12 months. There were no differences seen across time by group in low density lipoprotein or triglyceride levels.

Conclusion

Interventions like HeartHealth that focus on self-care and that are derived in collaboration with the community of interest are effective in medically underserved, socioeconomically distressed rural areas.

Acknowledgement/Funding

Patient Centered Outcomes Research Institute

P4540Obesity in patients with heart failure and without diabetes mellitus is associated with longer event-free survival only among those with high dietary sodium intake

Background

Obesity is paradoxically associated with better short- and long-term outcomes in patients with heart failure (HF) and without diabetes mellitus (DM). While excessive dietary sodium intake is common among obese persons, its impact on the association between obesity and outcomes has not been considered.

Aim

To determine whether dietary sodium intake levels would affect the association between obesity and better outcomes in patients with HF and without DM.

Method

A sample of 129 patients (age 60±12.4 years; 30% female) provided a single 24-hour urine collection sample to estimate dietary sodium intake. Patients were divided into 4 groups based on body mass index (BMI) and the sodium intake recommendation for HF of 3g/day (obese with high sodium intake [n=41; 32%], obese with low sodium intake [n=16; 12%], non-obese with high sodium intake [n=35; 27%], and non-obese with low sodium intake [n=37; 29%]). Patients were followed-up during an average period of 395 days to determine time to first event of all-cause hospitalization or death. Cox regression was used to determine the association between obesity and outcomes in the context of sodium intake after controlling for age, gender, NYHA class (I II vs. III IV) and LVEF.

Results

There were 41 patients (31.8%) who had an event of all-cause hospitalization or death. Obese patients with high sodium intake had 61% lower risk for events than those non-obese with low dietary sodium intake (figure). There were no differences in the event-free survival among other groups.

Conclusion

These data suggest that dietary sodium intake may be particularly important for obese patients with HF and without DM.

Tissue-regenerative potential of the secretome of γ-irradiated peripheral blood mononuclear cells is mediated via TNFRSF1B-induced necroptosis

Peripheral blood mononuclear cells (PBMCs) have been shown to produce and release a plethora of pro-angiogenetic factors in response to γ-irradiation, partially accounting for their tissue-regenerative capacity. Here, we investigated whether a certain cell subtype of PBMCs is responsible for this effect, and whether the type of cell death affects the pro-angiogenic potential of bioactive molecules released by γ-irradiated PBMCs. PBMCs and PBMC subpopulations, including CD4⁺ and CD8⁺ T cells, B cells, monocytes, and natural killer cells, were isolated and subjected to high-dose γ-irradiation. Transcriptome analysis revealed subpopulation-specific responses to γ-irradiation with distinct activation of pro-angiogenic pathways, cytokine production, and death receptor signalling. Analysis of the proteins released showed that interactions of the subsets are important for the generation of a pro-angiogenic secretome. This result was confirmed at the functional level by the finding that the secretome of γ-irradiated PBMCs displayed higher pro-angiogenic activity in an aortic ring assay. Scanning electron microscopy and image stream analysis of γ-irradiated PBMCs revealed distinct morphological changes, indicative for apoptotic and necroptotic cell death. While inhibition of apoptosis had no effect on the pro-angiogenic activity of the secretome, inhibiting necroptosis in stressed PBMCs abolished blood vessel sprouting. Mechanistically, we identified tumor necrosis factor (TNF) receptor superfamily member 1B as the main driver of necroptosis in response to γ-irradiation in PBMCs, which was most likely mediated via membrane-bound TNF-α. In conclusion, our study demonstrates that the pro-angiogenic activity of the secretome of γ-irradiated PBMCs requires interplay of different PBMC subpopulations. Furthermore, we show that TNF-dependent necroptosis is an indispensable molecular process for conferring tissue-regenerative activity and for the pro-angiogenic potential of the PBMC secretome. These findings contribute to a better understanding of secretome-based therapies in regenerative medicine.

Procedural memory consolidation is associated with heart rate variability and sleep spindles

Sleep and memory studies often focus on overnight rather than long‐term memory changes, traditionally associating overnight memory change (OMC) with sleep architecture and sleep patterns such as spindles. In addition, (para‐)sympathetic innervation has been associated with OMC after a daytime nap using heart rate variability (HRV). In this study we investigated overnight and long‐term performance changes for procedural memory and evaluated associations with sleep architecture, spindle activity (SpA) and HRV measures (R‐R interval [RRI], standard deviation of R‐R intervals [SDNN], as well as spectral power for low [LF] and high frequencies [HF]). All participants (N = 20, M_age = 23.40 ± 2.78 years) were trained on a mirror‐tracing task and completed a control (normal vision) and learning (mirrored vision) condition. Performance was evaluated after training (R1), after a full‐night sleep (R2) and 7 days thereafter (R3). Overnight changes (R2‐R1) indicated significantly higher accuracy after sleep, whereas a significant long‐term (R3‐R2) improvement was only observed for tracing speed. Sleep architecture measures were not associated with OMC after correcting for multiple comparisons. However, individual SpA change from the control to the learning night indicated that only “SpA enhancers” exhibited overnight improvements for accuracy and long‐term improvements for speed. HRV analyses revealed that lower SDNN and LF power was associated with better OMC for the procedural speed measure. Altogether, this study indicates that overnight improvement for procedural memory is specific for spindle enhancers, and is associated with HRV during sleep following procedural learning.

Cells´ Flow and Immune Cell Priming under alternating g-forces in Parabolic Flight

Gravitational stress in general and microgravity (µg) in particular are regarded as major stress factors responsible for immune system dysfunction in space. To assess the effects of alternating µg and hypergravity (hyper-g) on immune cells, the attachment of peripheral blood mononuclear cells (PBMCs) to adhesion molecules under flow conditions and the antigen-induced immune activation in whole blood were investigated in parabolic flight (PF). In contrast to hyper-g (1.8 g) and control conditions (1 g), flow and rolling speed of PBMCs were moderately accelerated during µg-periods which were accompanied by a clear reduction in rolling rate. Whole blood analyses revealed a "primed" state of monocytes after PF with potentiated antigen-induced pro-inflammatory cytokine responses. At the same time, concentrations of anti-inflammatory cytokines were increased and monocytes displayed a surface molecule pattern that indicated immunosuppression. The results suggest an immunologic counterbalance to avoid disproportionate immune responses. Understanding the interrelation of immune system impairing and enhancing effects under different gravitational conditions may support the design of countermeasures to mitigate immune deficiencies in space.

The Influence of Perforated Prosthetic Liners on Residual Limb Wound Healing: a Case Report

CASE DESCRIPTION

Good residual limb skin health is vital to successful prosthetic prescription. Unnatural loading profiles and excessive sweating can lead to skin and soft tissue problems. Perforated liners allow the transport of moisture away from the skin and allow negative pressure (a condition that has been shown to aid wound healing) to act directly on the residuum surface.

AIM

Assess the effects of perforated prosthetic liner use, particularly with respect to wound healing.

METHOD

Three patient histories were retrospectively reviewed following prescription of perforated prosthetic liners due to excessive sweating or prolonged residual limb health concerns. Photographic records from patient files were used to document changes in residual limb condition. Patients also provided subjective feedback regarding their experiences.

FINDINGS

Two cases described active amputees with persistent blistering irritated during exercise. Another case described a patient of low mobility level with a history of residual limb skin infections. All saw their conditions heal and reported a reduction in problematic sweating. Two patients reported cancelling surgical interventions after substantial improvements with the perforated liner.

DISCUSSION

These findings provide evidence that the use of perforated prosthetic liners allow improvements in residual limb health, while still permitting prosthetic use.

Sex differences in stress and immune responses during confinement in Antarctica

Background

Antarctica challenges human explorers by its extreme environment. The effects of these unique conditions on the human physiology need to be understood to best mitigate health problems in Antarctic expedition crews. Moreover, Antarctica is an adequate Earth-bound analogue for long-term space missions. To date, its effects on human physiology have been studied mainly in male cohorts though more female expeditioners and applicants in astronaut training programs are selected. Therefore, the identification of sex differences in stress and immune reactions are becoming an even more essential aim to provide a more individualized risk management.

Methods

Ten female and 16 male subjects participated in three 1-year expeditions to the German Antarctic Research Station Neumayer III. Blood, saliva, and urine samples were taken 1–2 months prior to departure, subsequently every month during their expedition, and 3–4 months after return from Antarctica. Analyses included cortisol, catecholamine and endocannabinoid measurements; psychological evaluation; differential blood count; and recall antigen- and mitogen-stimulated cytokine profiles.

Results

Cortisol showed significantly higher concentrations in females than males during winter whereas no enhanced psychological stress was detected in both sexes. Catecholamine excretion was higher in males than females but never showed significant increases compared to baseline. Endocannabinoids and N-acylethanolamides increased significantly in both sexes and stayed consistently elevated during the confinement. Cytokine profiles after in vitro stimulation revealed no sex differences but resulted in significant time-dependent changes. Hemoglobin and hematocrit were significantly higher in males than females, and hemoglobin increased significantly in both sexes compared to baseline. Platelet counts were significantly higher in females than males. Leukocytes and granulocyte concentrations increased during confinement with a dip for both sexes in winter whereas lymphocytes were significantly elevated in both sexes during the confinement.

Conclusions

The extreme environment of Antarctica seems to trigger some distinct stress and immune responses but—with the exception of cortisol and blood cell counts—without any major relevant sex-specific differences. Stated sex differences were shown to be independent of enhanced psychological stress and seem to be related to the environmental conditions. However, sources and consequences of these sex differences have to be further elucidated.

Osteosarcoma of the jaw - experience at the Medical University Vienna and comparative study with international tumor registries

OBJECTIVES

Osteosarcoma of the jaw (OSAJ) is fundamentally different in clinical practice from its peripheral counterparts. Studies are difficult to conduct due to low incidence rates. The primary aim of this study was to provide for the first time a comprehensive retrospective analysis of the treatment concepts and outcome data of OSAJ patients treated at the University Hospital Vienna and to compare these with two recently published studies on OSAJ. The clinical study was accompanied by a biomarker study investigating the prognostic relevance of melanoma-associated antigen-A (MAGE-A) in OSAJ specimens.

METHOD

Eighteen patients were included, and their outcomes were compared to published data. Immunohistochemistry was performed with mouse monoclonal antibodies against MAGE-A. Survival rates were estimated by the Kaplan-Meyer method. The log-rank test was used to analyze potential prognostic parameters. Fisher's exact test was performed to define the significant differences between the survival rates of the current study and the DOESAK registry.

RESULTS

Disease-specific survival was 93.8% after five and 56.3% after ten years. The development of metastases (p=0.033) or relapse (p=0.037) was associated with worsened outcomes in our group as well as in the comparative group. Despite the different treatment concepts of the study groups, survival rates were comparable. MAGE-A failed to show prognostic relevance for OSAJ patients.

CONCLUSIONS

Uncertainties about the optimal treatment strategies of OSAJ patients will currently remain. Thus, prospective studies of OSAJ are needed but are only feasible in a multicenter study setting, conducted over a prolonged time period.

Antibiofilm efficacy of curcumin in combination with 2-aminobenzimidazole against single- and mixed-species biofilms of Candida albicans and Staphylococcus aureus

Mixed fungal and bacterial biofilm associated infections of implants have been a huge challenge in health care because of the increased resistance to antimicrobials and the critical biological differences between fungi and bacteria. In this study, we evaluated the 2-aminobenzimidazole (2ABI) and curcumin (CUR) alone to inhibit planktonic cell growth, adhesion as well as single and mixed species biofilms of Candida albicans and Staphylococcus aureus on silicone. The combined effects between 2ABI and CUR on mixed species biofilm formation and pre-formed biofilm were assessed. Our work showed that 2ABI or CUR alone was effective as a sole agent, inhibiting planktonic growth, adhesion and the biofilm formation of bacteria and fungi on the silicone surface. The combination of 2ABI and CUR exhibited the enhanced effect on mixed biofilm compared to mono-drug therapy. The biofilm architecture was investigated by scanning electron microscopy (SEM) and the distinction of living/dead organisms within biofilm was examined by confocal laser scanning microscopy (CLSM). The combination activity was most potent on mixed biofilm. These results suggest the potential applicability of 2ABI and CUR to treatment of biofilm related device infections.

Evaluation of combined growth media for in vitro cultivation of oropharyngeal biofilms on prosthetic silicone

In the upper aerodigestive tract, biofilm deposits by oropharyngeal microbes can cause failure of medical polymer devices like voice prostheses. Previous studies on testing of inhibitive strategies still lack of comparability due to varying study protocols concerning growth media, microbial species and growth conditions. Goal of the study was therefore to test cultivation of a mixed biofilm of isolated oropharyngeal microbes under in vitro growth conditions using mixtures of common growth media. Mixtures of yeast peptone dextrose medium (YPD), fetal bovine serum (FBS), RPMI 1640, Yeast nitrogen base medium (YNB) and brain heart infusion (BHI) were tested to grow mixed biofilm deposits of Candida albicans, Candida tropicalis, Staphylococcus aureus, Streptococcus epidermidis, Rothia dentocariosa and Lactobacillus gasseri on medical grade silicone. Periodic assessment of living biofilm was performed over 22 days by a digital microscope and the cultivated biofilm structures were analyzed by scanning electron microscopy after completion of the study. Mixtures of BHI, YPD and FBS improved microscopic growth of multispecies biofilm deposits over time, while addition of RPMI and YNB resulted in reduction of visible biofilm deposit sizes. A mixtures of FBS 30% + YPD 70% and BHI 30% + YPD 70% showed enhanced support of permanent surface growth on silicone. Growth kinetics of in vitro multispecies biofilms can be manipulated by using mixtures of common growth media. Using mixtures of growth media can improve growth of longterm multispecies oropharyngeal biofilm models used for in vitro testing of antibiofilm materials or coatings for voice prostheses.

Matrix-associated chondrocyte transplantation for reconstruction of articulating surfaces in the temporomandibular joint: a pilot study covering medium- and long-term outcomes of 6 patients

Objective

Matrix-associated chondrocyte transplantation is routinely used in joints of the extremities but not in the temporomandibular joint (TMJ).

Study Design

We report the first case series in 7 patients of a tissue engineering approach to regenerate severely degraded articulating surfaces in the TMJ by simultaneously completely resurfacing both the mandibular condyle and the articular eminence/glenoid fossa with a commercially available collagen sponge seeded with autologous cells stabilized within a fibrin matrix. To facilitate healing, we temporarily employed a silicone membrane to protect the engineered tissues. The indications for surgery were posttraumatic fibro-osseous ankylosis, ankylosing osteoarthritis, or late-stage osteoarthritis.

Results

Six of the patients were recalled for follow-up after 3 years 6 months to 12 years 1 month. The maximum incisal opening was 18.2 ± 9.2 mm (range, 9-33 mm) before and 31.2 ± 13.6 mm (range, 12-47 mm) at the latest follow-up. Histologic specimens taken at 4 months showed beginning differentiation of fibrocytes into chondrocytes, whereas at 3 and 11 years, mature hyaline cartilage—not typical for the TMJ—was present.

Conclusions

We conclude that the reconstruction of TMJ surfaces by matrix-associated chondrocyte transplantation may become a routine method for cartilage regeneration in the TMJ in the future.

The effect of daytime napping and full-night sleep on the consolidation of declarative and procedural information

Many studies investigating sleep and memory consolidation have evaluated full-night sleep rather than alternative sleep periods such as daytime naps. This multi-centre study followed up on, and was compared with, an earlier full-night study (Schabus et al., 2004) investigating the relevance of daytime naps for the consolidation of declarative and procedural memory. Seventy-six participants were randomly assigned to a nap or wake group, and performed a declarative word-pair association or procedural mirror-tracing task. Performance changes from before to after a 90-min retention interval filled with sleep or quiet wakefulness were evaluated between groups. Associations between performance changes, sleep architecture, spindles, and slow oscillations were investigated. For the declarative task we observed a trend towards stronger forgetting across a wake period compared with a nap period, and a trend towards memory increase over the full-night. For the procedural task, accuracy was significantly decreased following daytime wakefulness, showed a trend to increase with a daytime nap, and significantly increased across full-night sleep. For the nap protocol, neither sleep stages, spindles, nor slow oscillations predicted performance changes. A direct comparison of day and nighttime sleep revealed that daytime naps are characterized by significantly lower spindle density, but higher spindle activity and amplitude compared with full-night sleep. In summary, data indicate that daytime naps protect procedural memories from deterioration, whereas full-night sleep improves performance. Given behavioural and physiological differences between day and nighttime sleep, future studies should try to characterize potential differential effects of full-night and daytime sleep with regard to sleep-dependent memory consolidation.

β-1,3-glucanase disrupts biofilm formation and increases antifungal susceptibility of Candida albicans DAY185

β-1,3-glucan plays a role in Candida biofilm formation and survival of biofilm-forming Candida to stresses. In this study, we evaluated the antibiofilm activity of β-1,3-glucanase, which can degrade poly-β(1→3)-glucose of Candida albicans biofilms. Biofilm was dispersed by 55.96%. β-1,3-glucanase had no effect on Candida planktonic growth as well as adhesion. β-1,3-glucanase markedly enhanced the antifungal susceptibility of fluconazole and amphotericin B. The examination using confocal laser scanning microscopy and scanning electron microscope confirmed the antibiofilm activity of β-1,3-glucanase. Our findings demonstrate that β-1,3-glucanase may be useful as an antibiofilm agent.

In vitro effects of particulate bone substitute materials on the resorption activity of human osteoclasts

Much research has been done on bone cells, but only a few studies deal with biomaterial-induced effects on human osteoclasts, which may take on an important role in the successful regeneration of bone. In order to highlight such effects, human peripheral blood mononuclear cells (PBMCs) were extracted from venous blood, differentiated to osteoclasts and then cultured in, the presence of five particulate hydroxyapatite (HA)/β-tricalcium phosphate (TCP) biomaterials, on bovine bone slices and glass cover slips. The biomaterials, AlgOSS 50/50 (50 % HA/50 % TCP), AlgOSS 20/80 (20 % HA/80 % TCP), Algipore (98 % HA), Cerasorb (100 % TCP) and Bio-Oss (100 % HA) were chosen to assess their influence on cell morphology and numbers. Light microscopic evaluation was performed during ongoing cell culture. After 21 d of cultivation, the biomaterial-induced effects on osteoclastic resorption of the bone slices were evaluated by scanning electron microscopy (SEM). Osteoclast-like cells were identified by TRAP staining. All five biomaterials showed larger area fractions of resorbed bone than the control (5.6 ± 6.8 %), as measured on SEM images. The purely hydroxyapatite-based Algipore (9.8 ± 9.7 %) and Bio-Oss (7.9 ± 8.8 %) showed significantly elevated area fraction rates (p ≤ 0.05) of bone resorption. Light microscope evaluation revealed a significant, but inhibiting effect of Cerasorb (p = 0.05). These data indicated that introducing of small biomaterial hydroxyapatite particles may have improved the performance of bone substitute materials.

Efficacy of carboxymethyl chitosan against Candida tropicalis and Staphylococcus epidermidis monomicrobial and polymicrobial biofilms

Polymicrobial biofilms with fungi and bacteria are the leading cause for the failure of medical devices and related infections. In this study, antibiofilm activities of carboxymethyl chitosan (CM-chitosan) on monomicrobial and polymicrobial biofilms of Staphylococcus epidermidis and Candida tropicalis in vitro were evaluated. CM-chitosan was effective as a sole agent, inhibiting both monomicrobial and polymicrobial biofilms in microplates and also on the silicone surface in short- and long-term periods. Biofilm architecture was investigated by scanning electron microscopy and confocal laser scanning microscopy was used to examine living/dead organisms within biofilm. CM-chitosan inhibited planktonic growth as well as adhesion. Further biofilm formation was inhibited by CM-chitosan added at 90min or 12h after biofilm initiation. CM-chitosan may serve as a possible antibiofilm agent to limit monomicrobial and polymicrobial biofilm.

Does Extracellular DNA Production Vary in Staphylococcal Biofilms Isolated From Infected Implants versus Controls?

BACKGROUND

Prosthetic implant infections caused by Staphylococcus aureus and epidermidis are major challenges for early diagnosis and treatment owing to biofilm formation on the implant surface. Extracellular DNA (eDNA) is actively excreted from bacterial cells in biofilms, contributing to biofilm stability, and may offer promise in the detection or treatment of such infections.

QUESTIONS/PURPOSES

(1) Does DNA structure change during biofilm formation? (2) Are there time-dependent differences in eDNA production during biofilm formation? (3) Is there differential eDNA production between clinical and control Staphylococcal isolates? (4) Is eDNA production correlated to biofilm thickness?

METHODS

We investigated eDNA presence during biofilm formation in 60 clinical and 30 control isolates of S aureus and S epidermidis. The clinical isolates were isolated from patients with infections of orthopaedic prostheses and implants: 30 from infected hip prostheses and 30 from infected knee prostheses. The control isolates were taken from healthy volunteers who had not been exposed to antibiotics and a hospital environment during the previous 3 and 12 months, respectively. Control S epidermidis was isolated from the skin of the antecubital fossa, and control S aureus was isolated from the nares. For the biofilm experiments the following methods were used to detect eDNA: (1) fluorescent staining with 4',6-diamidino-2-phenylindole (DAPI), (2) eDNA extraction using a commercial kit, and (3) confocal laser scanning microscopy for 24-hour biofilm observation using propidium iodide and concanavalin-A staining; TOTO^®-1 and SYTO^® 60 staining were used for observation and quantification of eDNA after 6 and 24 hours of biofilm formation. Additionally antibiotic resistance was described.

RESULTS

eDNA production as observed by confocal laser scanning microscopy was greater in clinical isolates than controls (clinical isolates mean ± SD: 1.84% ± 1.31%; control mean ± SD: 1.17% ± 1.37%; p < 0.005) after 6 hours of biofilm formation. After 24 hours, the amount of eDNA was greater in biofilms of S epidermidis than in biofilms of S aureus (S aureus mean ± SD: 1.35% ± 2.0%; S epidermidis mean ± SD: 6.42% ± 10.6%; p < 0.05). Clinical isolates of S aureus and S epidermidis produced more eDNA than control isolates at 6 hours of biofilm formation. The extraction method also showed that clinical isolates produced substantially greater amounts of eDNA than controls.

CONCLUSIONS

S aureus and S epidermidis exhibit a differential production of DNA with time. Clinical isolates associated with implant infections produce greater amounts of eDNA than controls. Future research might focus on the diagnostic value of eDNA as a surrogate laboratory marker for biofilm formation in implant infections.

CLINICAL RELEVANCE

eDNA should be considered as a potential future diagnostic tool or even a possible target to modify biofilms for successful treatment of biofilm-associated infections.

Small cell lung cancer: model of circulating tumor cell tumorospheres in chemoresistance

Small cell lung cancer (SCLC) represents 15% of lung cancers and is characterized by early dissemination, development of chemoresistance and a poor prognosis. A host of diverse drugs failed invariably and its mechanisms of global chemoresistance have not been characterized so far. SCLC represents the prototype of an aggressive and highly metastatic tumor which is ultimately refractory to any treatment. High numbers of circulating tumor cells (CTCs) allowed us to establish 5 CTC cell lines (BHGc7, 10, 16, 26 and UHGc5) from patients with recurrent SCLC. These cell lines exhibit the typical SCLC markers and CTCs of all patients developed spontaneously large multicellular aggregates, termed tumorospheres. Ki67 and carbonic anhydrase 9 (CAIX) staining of tumorosphere sections revealed quiescent and hypoxic cells, respectively. Accordingly, comparison of the chemosensitivity of CTC single cell suspensions with tumorospheres demonstrated increased resistance of the clusters against chemotherapeutics commonly used for treatment of SCLC. Therefore, global chemoresistance of relapsing SCLC seems to rely on formation of large tumorospheres which reveal limited accessibility, lower growth fraction and hypoxic conditions. Since similar tumor spheroids were found in other tumor types, SCLC seems to represent a unique tumor model to study the association of CTCs, metastasis and drug resistance.

Sexual isolation promotes divergence between parapatric lake and stream stickleback

Speciation can be initiated by adaptive divergence between populations in ecologically different habitats, but how sexually based reproductive barriers contribute to this process is less well understood. We here test for sexual isolation between ecotypes of threespine stickleback fish residing in adjacent lake and stream habitats in the Lake Constance basin, Central Europe. Mating trials exposing females to pairings of territorial lake and stream males in outdoor mesocosms allowing for natural reproductive behaviour reveal that mating occurs preferentially between partners of the same ecotype. Compared to random mating, this sexual barrier reduces gene flow between the ecotypes by some 36%. This relatively modest strength of sexual isolation is surprising because comparing the males between the two ecotypes shows striking differentiation in traits generally considered relevant to reproductive behaviour (body size, breeding coloration, nest size). Analysing size differences among the individuals in the mating trials further indicates that assortative mating is not related to ecotype differences in body size. Overall, we demonstrate that sexually based reproductive isolation promotes divergence in lake-stream stickleback along with other known reproductive barriers, but we also caution against inferring strong sexual isolation from the observation of strong population divergence in sexually relevant traits.

Activities of Daily Living and Depressive Symptoms in Patients with Subjective Cognitive Decline, Mild Cognitive Impairment, and Alzheimer's Disease

BACKGROUND

Subjective cognitive decline (SCD) may be an early indicator for an increased risk of dementia. The exact definition of SCD remains unclear and has recently become a major research interest.

OBJECTIVES

To determine impairments in activities of daily living (ADL) and depressive symptoms in elderly individuals with SCD, mild cognitive impairment (MCI), and Alzheimer's disease (AD).

METHODS

We included 752 consecutive patients suffering from SCD, non-amnestic (naMCI) or amnestic MCI (aMCI), AD, and 343 healthy controls into this prospective cohort study. A neuropsychological test battery, B-ADL and BDI-II was performed.

RESULTS

SCD patients showed a decreased performance in ADL compared to controls. Performance in ADL declined concurrently with cognitive abilities along the controls-SCD-naMCI-aMCI-AD continuum. Individuals with cognitive complains, no matter if SCD, MCI, or AD patients, reported more often depressive symptoms compared to healthy controls without complaints. Within all five cognitive subgroups, patients with depressive symptoms reported more difficulties in ADL in comparison to patients without depressive symptoms. Adjusting for depressive symptoms, there was no significant group difference between the control versus the SCD group (OR 1.1, CI 0.6-1.7).

CONCLUSIONS

SCD is a heterogeneous clinical condition. Specific features such as slightly impaired ADL and depressive symptoms are associated with SCD. Clinical markers may serve as an indicator for preclinical AD and in combination with biomarkers guide to an early diagnosis of a progressive neurodegenerative disease.

Inhibition of mixed fungal and bacterial biofilms on silicone by carboxymethyl chitosan

Mixed biofilms with fungi and bacteria are the leading cause for the failure of medical silicone devices, such as voice prostheses in laryngectomy. In this study, we determined the effect of carboxymethyl chitosan (CM-chitosan) on mixed biofilm formation of fungi and bacteria on silicone which is widely used for construction of medical devices. Mixed biofilm formations were inhibited 72.87% by CM-chitosan. Furthermore, CM-chitosan significantly decreased the metabolic activity of the biofilms using 2, 3-bis (2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5 carboxanilide (XTT) reduction assay. The examination using confocal laser scanning microscopy and scanning electron microscope confirmed that CM-chitosan inhibited the mixed biofilm and damaged the cells. Effects of CM-chitosan on different stages of biofilms were also evaluated. CM-chitosan inhibited the adhesion of fungi and bacteria with an efficiency of >90%. It prevented biofilm formation at efficiencies of 69.86%, 50.88% and 46.58% when CM-chitosan was added at 90min, 12h and 24h after biofilm initiation, respectively. Moreover, CM-chitosan inhibited Candida yeast-to-hyphal transition. CM-chitosan was not only able to inhibit the metabolic activity of biofilms, but also active upon the establishment and development of biofilm. Therefore, CM-chitosan may serve as a possible antibiofilm agent to limit biofilm formation on voice prostheses.

Health-Related Quality of Life in Patients with Subjective Cognitive Decline and Mild Cognitive Impairment and its Relation to Activities of Daily Living

BACKGROUND

Health related quality of life (HRQOL) is an important issue in the context of dementia care.

OBJECTIVES

The purpose of this study was to investigate HRQOL in patients with subjective cognitive decline (SCD) and mild cognitive impairment (MCI) and its relation to Activity of Daily Living (ADL).

METHODS

In this cross sectional study, four experimental groups (each n = 98), controls, SCD, naMCI and aMCI, were compared. For data collection, neuropsychological methods (NTBV) and psychological questionnaires (SF-36 and B-ADL) were used. Multivariate analysis of variance was calculated to detect differences in HRQOL between groups. Correlations between HRQOL and ADL were explored.

RESULTS

The dimensions of HRQOL showed mainly consistent differences between the control and the SCD group and MCI subgroups. In almost every dimension of HRQOL, the control group scored higher than subjects with SCD, naMCI, or aMCI. The controls showed low to moderate negative correlations between HQROL and B-ADL in some dimensions of the HRQOL. In the SCD group, low negative correlations with ADL were observed in some HRQOL scales. Low to moderate correlations were found between each scale of the SF-36 and the B-ADL in both MCI subtypes. We found gender differences in HRQOL.

CONCLUSION

In conclusion, we could demonstrate that patients with SCD report reduced quality of life. This knowledge is important to get a better understanding of the individuals with SCD and may pave the way for the development of early intervention.