Micro-endoscopy of the human vas deferens: a feasibility study of a novel device in several ex vivo models

The aim of this study was to show limitation as well as potential of micro-endoscopy techniques as an innovative diagnostic and therapeutic approach in andrology. Two kinds of custom-made micro-endoscopes (ME) were tested in ex vivo vas deferens specimen and in post-mortem whole body. The semi-rigid ME included a micro-optic (0.9 mm outer diameter [OD], 10.000 pixels, 120° vision angle [VE], 3-20 mm field depth [FD]) and an integrated fibre-optic light source. The flexible ME was composed of a micro-optic (OD = 0.6 mm, 6.000 pixels, 120° VE, 3-20 mm FD). The ex vivo study included retrograde investigation of the vas deferens (surgical specimen n = 9, radical prostatectomy n = 3). The post-mortem investigation (n = 4) included the inspection of the vas deferens via both approaches. The results showed that antegrade and retrograde rigid endoscopy of the vas deferens were achieved as a diagnostic tool. The working channel enabled therapeutic use including biopsies or baskets. Using the flexible ME, the orifices of the ejaculatory ducts were identified. In vivo cadaveric retrograde cannulation of the orifices was successful. Post-mortem changes of verumontanum hindered the examinations beyond. Orifices were identified shaded behind a thin transparent membrane. Antegrade vasoscopy using flexible ME was possible up to the internal inguinal ring. Further advancement was impossible because of anatomical angle and lack adequate vision guidance. The vas deferens interior was clearly visible and was documented by pictures and movies. Altogether, the described ME techniques were feasible and effective, offering the potential of innovative diagnostic and therapeutic approaches for use in the genital tract. Several innovative indications could be expected.

Potential of the polymer poly-[2-(tert-butylamino) methylstyrene] as antimicrobial packaging material for meat products

AIMS

The objective of the study was to investigate the antimicrobial potential of a new SAM(®) polymer poly(TBAMS) as packaging material for meat products.

METHODS AND RESULTS

The influence of temperature, time and product factors on the antimicrobial activity of poly(TBAMS) against different bacteria was determined using a modified test method based on the Japanese Industrial Standard 2801:2000. Results showed a significant reduction in bacterial counts on poly(TBAMS) compared with the reference material of several meat-specific micro-organisms after 24 h at 7°C. Bacterial counts of Staphylococcus aureus, Listeria monocytogenes, Lactobacillus spp., Brochothrix thermosphacta and Escherichia coli were reduced by >4·0 log10  units. Pseudomonas fluorescens was less sensitive to poly(TBAMS) within 24 h between 2 and 7°C. Prolonging the storage time to 48 h, however, resulted in an increased reduction rate. Furthermore, antimicrobial activity was also observed if meat components in the form of meat extract, meat juice or bovine serum albumin protein were present. Antimicrobial activity was also achieved if inoculated with mixed cultures.

CONCLUSIONS

Poly(TBAMS) showed antimicrobial properties under conditions typical for meat supply chains.

SIGNIFICANCE AND IMPACT OF THE STUDY

Poly(TBAMS) bears a high potential to increase safety and shelf life of meat products.

Pull-out stability of anchors for rotator cuff repair is also increased by bio-absorbable augmentation: a cadaver study

INTRODUCTION

Osteoporosis is a highly focused issue in current scientific research and clinical treatment. Especially in rotator cuff repair, the low bone quality of patients suffering from osteoporosis is an important issue. In this context, non-biological solutions using PMMA for anchor augmentation have been developed in the recent past. The aim of this study was to evaluate whether augmentation of suture anchors using bio-absorbable osteoconductive fiber-reinforced calcium phosphate results in improved failure load of suture anchors as well.

MATERIALS AND METHODS

Altogether 24 suture anchors (Corkscrew FT 1 Suture Anchors, Arthrex, Naples, FL, USA) were evaluated by applying traction until pullout in 12 paired fresh frozen human cadaver humeri using a servo-hydraulic testing machine. Inclusion criteria were an age of more than 64 years, a macroscopically intact RC and an intact bone. The anchors were evaluated at the anterolateral and posteromedial aspect of the greater tuberosity. 12 suture anchors were augmented and 12 suture anchors were conventionally inserted.

RESULTS

The failure load was significantly enhanced by 66.8 % by the augmentation method. The fiber-reinforced calcium phosphate could be easily injected and applied.

CONCLUSION

The bio-absorbable cement in this study could be a promising augmentation material for RC reconstructions, but further research is necessary-the material has to be evaluated in vivo.

[Insights into cystic fibrosis-related bone disease]

With the increasing life expectancy of patients with cystic fibrosis (CF), prevalence of late complications such as CF-related bone disease (CFBD) has increased. It was initially described in 24% of the adult population with CF and has also been reported in the pediatric population. CFBD is multifactorial and progresses in different steps. Both decreased bone formation and increased bone resorption (in different amounts) are observed. CFBD is likely primitive (directly related to the CFTR defect itself), but is also worsened by acquired secondary factors such as lung infections, chronic inflammation, denutrition, vitamin deficiency, and decreased physical activity. CFBD may be clinically apparent (i.e., mainly vertebral and costal fractures), or clinically asymptomatic (therefore corresponding to abnormalities in bone density and architecture). CFBD management mainly aims to prevent the occurrence of fractures. Prevention and regular monitoring of bone disease as early as 8 years of age is of the utmost importance, as is the control of possible secondary deleterious CFBD factors. New radiological tools, such as high-resolution peripheral quantitative computed tomography, allow an accurate evaluation of cortical and trabecular bone micro-architecture in addition to compartmental density; as such, they will likely improve the assessment of the bone fracture threat in CF patients in the near future.

Ultraviolet absorbing compounds provide a rapid response mechanism for UV protection in some reef fish

The external mucus surface of reef fish contains ultraviolet absorbing compounds (UVAC), most prominently Mycosporine-like Amino Acids (MAAs). MAAs in the external mucus of reef fish are thought to act as sunscreens by preventing the damaging effects of ultraviolet radiation (UVR), however, direct evidence for their protective role has been missing. We tested the protective function of UVAC's by exposing fish with naturally low, Pomacentrus amboinensis, and high, Thalassoma lunare, mucus absorption properties to a high dose of UVR (UVB: 13.4W∗m(-2), UVA: 6.1W∗m(-2)) and measuring the resulting DNA damage in the form of cyclobutane pyrimidine dimers (CPDs). For both species, the amount of UV induced DNA damage sustained following the exposure to a 1h pulse of high UVR was negatively correlated with mucus absorbance, a proxy for MAA concentration. Furthermore, a rapid and significant increase in UVAC concentration was observed in P. amboinensis following UV exposure, directly after capture and after ten days in captivity. No such increase was observed in T. lunare, which maintained relatively high levels of UV absorbance at all times. P. amboinensis, in contrast to T. lunare, uses UV communication and thus must maintain UV transparent mucus to be able to display its UV patterns. The ability to rapidly alter the transparency of mucus could be an important adaptation in the trade off between protection from harmful UVR and UV communication.

Movement related cortical potentials in severe chronic stroke

Movement related cortical potentials (MRCPs) have been studied for many years and controlled using brain computer interfaces (BCIs). Furthermore, MRCPs have been proposed as reliable and immediate indicators of cortical reorganizations in motor learning and after stroke. In this study MRCPs preceding and during hand movements in severe chronic stroke were investigated. Eight severely impaired (no residual finger extension) chronic stoke patients underwent EEG and EMG recordings during a cue triggered hand movement paradigm. Four patients presented subcortical lesions only while the other four presented mixed (cortical and subcortical) lesions. MRCPs were measured before (slow cortical potentials SCPs) and at movement onset (motor potentials MPs). SCPs were observed during paretic hand movements only. Latencies were longer and reached their negativity peak earlier during paretic hand movement. When dividing the patients in subcortical only and mixed lesion patients, we observed significantly bigger MP peak amplitudes over the lesioned hemisphere during paretic and healthy hand movements in subcortical stroke patients. Furthermore, we observed a significant difference in MP peak latency between subcortical and mixed stroke patients during paretic hand movements. We demonstrated for the first time significant differences between subcortical only and mixed (cortical and subcortical) stroke patients' MRCPs during motor preparation and execution. Furthermore, we demonstrated how stroke produces a longer MRCP and that lesion location affects MP peak amplitude and latency. Finally, we propose the use MRCP based BCIs to reduce their duration (towards normal) and induce motor function recovery.

Observation of a New Narrow Axial-Vector Meson a1(1420)

The COMPASS Collaboration at CERN has measured diffractive dissociation of 190  GeV/c pions into the π(-)π(-)π(+) final state using a stationary hydrogen target. A partial-wave analysis (PWA) was performed in bins of 3π mass and four-momentum transfer using the isobar model and the so far largest PWA model consisting of 88 waves. A narrow peak is observed in the f0(980)π channel with spin, parity and C-parity quantum numbers J(PC)=1(++). We present a resonance-model study of a subset of the spin-density matrix selecting 3π states with J(PC)=2(++) and 4(++) decaying into ρ(770)π and with J(PC)=1(++) decaying into f0(980)π. We identify a new a1 meson with mass (1414(-13)(+15))  MeV/c2 and width (153(-23)(+8))  MeV/c2. Within the final states investigated in our analysis, we observe the new a1(1420) decaying only into f0(980)π, suggesting its exotic nature.

Measurement of the charged-pion polarizability

The COMPASS collaboration at CERN has investigated pion Compton scattering, π(-)γ→π(-)γ, at center-of-mass energy below 3.5 pion masses. The process is embedded in the reaction π(-)Ni→π(-)γNi, which is initiated by 190 GeV pions impinging on a nickel target. The exchange of quasireal photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, Q(2)<0.0015  (GeV/c)(2). From a sample of 63,000 events, the pion electric polarizability is determined to be α(π)=(2.0±0.6(stat)±0.7(syst))×10(-4)  fm(3) under the assumption α(π)=-β(π), which relates the electric and magnetic dipole polarizabilities. It is the most precise measurement of this fundamental low-energy parameter of strong interaction that has been addressed since long by various methods with conflicting outcomes. While this result is in tension with previous dedicated measurements, it is found in agreement with the expectation from chiral perturbation theory. An additional measurement replacing pions by muons, for which the cross-section behavior is unambiguously known, was performed for an independent estimate of the systematic uncertainty.

Fine-scale spatial genetic dynamics over the life cycle of the tropical tree Prunus africana

Studying fine-scale spatial genetic patterns across life stages is a powerful approach to identify ecological processes acting within tree populations. We investigated spatial genetic dynamics across five life stages in the insect-pollinated and vertebrate-dispersed tropical tree Prunus africana in Kakamega Forest, Kenya. Using six highly polymorphic microsatellite loci, we assessed genetic diversity and spatial genetic structure (SGS) from seed rain and seedlings, and different sapling stages to adult trees. We found significant SGS in all stages, potentially caused by limited seed dispersal and high recruitment rates in areas with high light availability. SGS decreased from seed and early seedling stages to older juvenile stages. Interestingly, SGS was stronger in adults than in late juveniles. The initial decrease in SGS was probably driven by both random and non-random thinning of offspring clusters during recruitment. Intergenerational variation in SGS could have been driven by variation in gene flow processes, overlapping generations in the adult stage or local selection. Our study shows that complex sequential processes during recruitment contribute to SGS of tree populations.

Revisiting the phylogeography and demography of European badgers (Meles meles) based on broad sampling, multiple markers and simulations

Although the phylogeography of European mammals has been extensively investigated since the 1990s, many studies were limited in terms of sampling distribution, the number of molecular markers used and the analytical techniques employed, frequently leading to incomplete postglacial recolonisation scenarios. The broad-scale genetic structure of the European badger (Meles meles) is of interest as it may result from historic restriction to glacial refugia and/or recent anthropogenic impact. However, previous studies were based mostly on samples from western Europe, making it difficult to draw robust conclusions about the location of refugia, patterns of postglacial expansion and recent demography. In the present study, continent-wide sampling and analyses with multiple markers provided evidence for two glacial refugia (Iberia and southeast Europe) that contributed to the genetic variation observed in badgers in Europe today. Approximate Bayesian computation provided support for a colonisation of Scandinavia from both Iberian and southeastern refugia. In the whole of Europe, we observed a decline in genetic diversity with increasing latitude, suggesting that the reduced diversity in the peripheral populations resulted from a postglacial expansion processes. Although MSVAR v.1.3 also provided evidence for recent genetic bottlenecks in some of these peripheral populations, the simulations performed to estimate the method's power to correctly infer the past demography of our empirical populations suggested that the timing and severity of bottlenecks could not be established with certainty. We urge caution against trying to relate demographic declines inferred using MSVAR with particular historic or climatological events.