Value of Cardiopulmonary Exercise Testing in the Prognosis Assessment of Chronic Obstructive Pulmonary Disease Patients: A Retrospective, Multicentre Cohort Study.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is one of the most common chronic diseases associated with high mortality. Previous studies suggested a prognostic role for peak oxygen uptake (VO2peak) assessed during cardiopulmonary exercise testing (CPET) in patients with COPD. However, most of these studies had small sample sizes or short follow-up periods, and despite their relevance, CPET parameters are not included in the Global Initiative for Chronic Obstructive Lung Disease (GOLD) tool for assessment of severity. OBJECTIVES: We therefore aimed to assess the prognostic value of CPET parameters in a large cohort of outpatients with COPD. METHODS: In this retrospective, multicentre cohort study, medical records of patients with COPD who underwent CPET during 2004-2017 were reviewed and demographics, smoking habits, GOLD grade and category, exacerbation frequency, dyspnoea score, lung function measurements, and CPET parameters were documented. Relationships with survival were evaluated using Kaplan-Meier analysis, Cox regression, and receiver operating characteristic (ROC) curves. RESULTS: Of a total of 347 patients, 312 patients were included. Five-year and 10-year survival probability was 75% and 57%, respectively. VO2peak significantly predicted survival (hazard ratio: 0.886 [95% confidence interval: 0.830; 0.946]). The optimal VO2peak threshold for discrimination of 5-year survival was 14.6 mL/kg/min (area under ROC curve: 0.713). Five-year survival in patients with VO2peak <14.6 mL/kg/min versus ≥ 14.6 mL/kg/min was 60% versus 86% in GOLD categories A/B and 64% versus 90% in GOLD categories C/D. CONCLUSIONS: We confirm that VO2peak is a highly significant predictor of survival in COPD patients and recommend the incorporation of VO2peak into the assessment of COPD severity.

Infected tibia defect fractures treated with the Masquelet technique.

The treatment after open and infected fractures with extensive soft tissue damage and bone deficit remains a challenging clinical problem. The technique described by Masquelet, using a temporary cement spacer to induce a membrane combined with reconstructive soft tissue coverage, is a possible solution. This study describes the work-up, operative procedure, complications, and the outcome of a homogenous group of patients with an open and infected tibia fracture and segmental bone loss treated with the Masquelet technique (MT).This retrospective study evaluates patients having sustained an open tibia fracture treated with the MT between 2008 and 2013 with a follow up of at least 1 year. The defect was either primary, caused by a high-grade open fracture or secondary due to a non-union after an open fracture. Prerequisite conditions prior to the procedure of the Masquelet were a defect zone with eradicated infection, an intact soft tissue cover and stability provided by an external fixation.Volume of the defect, time until the implantation of the spacer, time of the spacer in situ and the time to clinical and radiological union were evaluated. Patient records were screened for reoperations and complications. The functional clinical outcome was measured.Eight patients were treated with a follow up over 1 year. The spacer was implanted after a median of 11 (2-70) weeks after the accident. The predefined conditions for the Masquelet phase were reached after a median of 12 (7-34) operations.Seven patients required reconstructive soft tissue coverage. The volume of the defect had a median of 111 (53.9-621.6) cm, the spacer was in situ for a median of 12 (7-26) weeks. Radiological healing was achieved in 7 cases after a median time of 52 (26-93) weeks.Full weight bearing was achieved after a median time of 16 (11-24) weeks. Four patients needed a reoperation. The lower limb functional index was a median of 60% (32-92%).Seven out of 8 patients treated in this group of severe open and infected tibia fractures did both clinically and radiologically heal. Due to the massive destruction of the soft tissue, patients needed several reoperations with soft tissue debridements and reconstruction before the spacer and the bone graft could be implanted.

High levels of dioxin-like PCBs found in organic-farmed eggs caused by coating materials of asbestos-cement fiber plates: A case study.

During a regional monitoring project of organic-farmed, free-range and cage-free eggs, high levels of dioxin-like compounds were detected in organic-farmed eggs, using the dioxin responsive chemical-activated luciferase gene expression (DR-CALUX®) bioassay. Further evaluations performed with GC-HRMS (gas chromatography in combination with high resolution mass spectrometry) revealed elevated amounts of non-dioxin-like (non-dl) polychlorinated biphenyls (PCBs) dominated by most lipophilic congeners like PCB 138, 153 and 180 and of dioxin-like (dl) PCBs, with a congener pattern in the descending order of PCB 118, 156, 167, 105, 189, 157, 105, 126 and PCB 77. Contaminations with polychlorinated dibenzo-p-dioxins (PCDDs) appeared of minor priority, with only hepta- and octa-substituted dioxins above their limits of quantification (LOQs). The pattern of polychlorinated dibenzofurans (PCDFs) was dominated by low amounts of tetra- and penta-chlorinated congeners. To identify the source of contamination, several samples of organic-farmed eggs, soil, laying hens, feedstuff, corrugated asbestos-cement cover plates (ACPs), stable dust and debris collected in the gutter of the stable, were analyzed. Comparing PCB congener-pattern of individual samples, the source was traced back to the coating of ACPs, which covered roof and sidewalls of the stable. Because coating materials probably have been used for roofing and cladding in many countries worldwide, there is a high probability that the presented case report is not a local incident but rather describes a new source of PCB contamination, yet widely unknown or underestimated.

Reconstruction after talar fractures.

Malunited and nonunited talar fractures cause significant disability. Distinction between partial and total avascular necrosis (AVN) determines the choice of treatment. Patients who have minimal or no AVN and well-preserved joint cartilage may be amenable to corrective osteotomy through the malunited fracture or removal of the pseudoarthrosis. Secondary reconstruction with joint preservation leads to considerable functional improvement in painful talar malunions and nonunions in reliable patients. If symptomatic arthritis is present, arthrodeses and correction of deformity through the fusion or with additional osteotomies provide predictable results, although they do not restore normal foot function. Fusions should be limited to the affected joint. If the subtalar joint shows severe arthritic changes, every attempt should be made to salvage the ankle and talonavicular joints.

Photoablation of inner limiting membrane and inner retinal layers using the Erbium:YAG-laser: an in vitro study.

BACKGROUND AND OBJECTIVES: To explore the potential of Er:YAG-laser irradiation for precise and tractionless retinal tissue and inner limiting membrane ablation. MATERIALS AND METHODS: We used free-running Er:YAG-laser irradiation (lambda = 2.94 microm) transmitted either through a 10 cm long low-OH-quartz fiber or a 2 m long sapphire fiber that produced a more homogenous light distribution at the fiber tip. Retinal ablation in porcine retinal explants was performed under air or perfluorodecaline (PFD). Ablation depth was evaluated by optical coherence tomography (OCT) and from histologic sections. RESULTS: A radiant exposure of 5.0 J/cm(2) delivered through a low-OH-quartz fiber and PFD caused a complete transsection of the neurosensory retina. Radiant exposures between 3.5 and 2.0 J/cm(2) resulted in marked variations of ablation depth and adjacent thermal damage. By contrast, laser pulses of 4.0 and 3.0 J/cm(2) transmitted through the sapphire fiber produced more homogenous defect patterns and less thermal damage. Close to the ablation threshold, with 1.0-2.0 J/cm(2), ablation was limited to a 10-20 microm thin layer of the neural retina. CONCLUSIONS: We achieved in vitro ablation of inner retinal layers, but could not produce selective and reproducible ILM removal.

Anatomical reconstruction of malunited talus fractures: a prospective study of 10 patients followed for 4 years.

BACKGROUND: Malunions or nonunions after displaced talar fractures cause significant disability. Salvage procedures such as corrective arthrodesis do not restore normal foot function. METHODS: Between 1994 and 2002, we treated 10 patients (aged 15-50 years) who had painful malunions with secondary anatomical reconstruction, at a mean of 1 year after sustaining displaced fractures of the talar body or neck. 5 patients were classified as type I (malunion and/or residual joint displacement), 2 as type II (nonunion with displacement) and 3 as type III (malunion with partial avascular necrosis, AVN). Correction was by an osteotomy through the malunited fracture or removal of the pseudarthrosis. Internal fixation was achieved with screws and additional bone grafting if necessary. RESULTS: No wound healing problems or infections were seen. Solid union was obtained without redislocation in all cases, with no signs of development or progression of AVN. At a mean of 4 (1-8) years after reconstruction, all patients were satisfied with the result--except one patient who required ankle fusion 8 years after reconstruction. The mean AOFAS Ankle Hindfoot Score increased from 38 to 86 (p < 0.001). INTERPRETATION: Secondary anatomical reconstruction with joint preservation leads to considerable functional improvement in painful talar malunions. Partial AVN does not preclude good to excellent functional results. The quality of the bone stock and joint cartilage (rather than the time from injury) appears to be important for the choice of treatment.

Experimental imaging of intracorneal ring segments with optical coherence tomography.

PURPOSE: To investigate the imaging of corneal structures with optical coherence tomography (OCT) after implantation of intracorneal ring segments (ICRS). METHODS: In an experimental study with six porcine eyes, qualitative and quantitative imaging with corneal OCT using a wavelength of 1310 nm after implantation of ICRS was performed. The optical results were compared with light microscopy of the histological sections. RESULTS: In corneal OCT, the ICRS revealed marked hyporeflective intrastromal areas, which correlated well with macroscopic and microscopic findings. Corneal OCT enabled precise images of the incision depth for the implantation of ICRS, and the exact intrastromal segment position. CONCLUSIONS: Noncontact slit lamp-adapted corneal optical coherence tomography could be employed to clinically monitor corneal changes after implantation of ICRS, evaluate the depth of the segments to correlate refractive changes, and quantify the stromal wound healing response.

Histopathological correlation of corneal diseases with optical coherence tomography.

PURPOSE: To correlate the cross-sectional images of corneal diseases obtained by optical coherence tomography (OCT) with light microscopy (LM) to determine the corneal components represented in OCT images. METHODS: In a prospective comparative tissue study clinicopathological correlations of six patients with pseudophakic bullous keratopathy ( n=3), advanced keratoconus ( n=1), persistent epithelial defect with corneal thinning ( n=1), and retrocorneal membrane ( n=1) were included. Immediately before a planned penetrating keratoplasty (PKP) noncontact slitlamp-adapted OCT of the cornea was performed. After PKP and following standard histological processing the specimens were examined under LM to compare qualitatively the morphology, and quantitatively the morphometry at selected corneal locations. RESULTS: The cross-sectional optical-reflectivity profiles enabled the reproducible morphological evaluation of the corneal structures and changes. Layers of relative high reflectivity corresponded to the anterior corneal surface and internal stromal layers. In contrast, the deeper corneal epithelial layer demonstrated relative low reflectivity by OCT. An increase in light reflectivity corresponded to corneal scarring, irregularities of the corneal lamellae, and deposition of basal membrane material. Low signal intensity was particularly due to fluid accumulations and shadowing. The most prominent changes were caused by corneal scars or edematous tissue. The morphometric analysis with OCT revealed, in this study, thickness measurements ranging from 31 to 902 micro m. Although the mean OCT thickness values were up to 9% ( P=0.014) higher than those derived from LM, there was a significant positive correlation (r=0.94; P<0.001) between corneal OCT and the light-microscopic measurements. CONCLUSION: Noncontact slitlamp-adapted corneal OCT revealed a good correlation with histological sections. The differences noted were partly related to shrinking processes during preparation. Thus, with certain limitations, OCT allows a non-invasive optical biopsy of pathological structures in corneal diseases.

Transscleral optical coherence tomography--an experimental study in ex-vivo human eyes.

BACKGROUND AND OBJECTIVE: To evaluate the potentials of a 1310-nm optical coherence tomography (OCT) system to penetrate the highly backscattering sclera in enucleated human eyes and provide visualization of intraocular structures by transscleral imaging. STUDY DESIGN/MATERIALS AND METHODS: OCT-images were generated by an experimental prototype (Medical Laser Center, Lübeck, Germany) using a superluminescence diode with a wavelength of 1310 nm. OCT-images were taken from two enucleated human eyes using 100-200 axial scans with 60 Hz line scan frequency and compared to subsequent histologic sections. RESULTS: Transscleral OCT allowed penetration of the sclera and the anterior chamber angle could be completely identified. Some change within the anterior eye segment could be demonstrated with high accuracy. Additionally, limited demonstration of the ciliary body region was achieved. Due to limited signal intensity no detailed imaging of the pars plana and pars plicata region was possible. However, more posterior measurements allowed transscleral visualization of a retinal detachment. CONCLUSIONS: OCT using lightsources with a wavelength longer than that used in conventional OCT provides a promising imaging technique at high resolution allowing transscleral imaging of the anterior eye segment.