Leveraging cross-species transcription factor binding site patterns: from diabetes risk loci to disease mechanisms.

Genome-wide association studies have revealed numerous risk loci associated with diverse diseases. However, identification of disease-causing variants within association loci remains a major challenge. Divergence in gene expression due to cis-regulatory variants in noncoding regions is central to disease susceptibility. We show that integrative computational analysis of phylogenetic conservation with a complexity assessment of co-occurring transcription factor binding sites (TFBS) can identify cis-regulatory variants and elucidate their mechanistic role in disease. Analysis of established type 2 diabetes risk loci revealed a striking clustering of distinct homeobox TFBS. We identified the PRRX1 homeobox factor as a repressor of PPARG2 expression in adipose cells and demonstrate its adverse effect on lipid metabolism and systemic insulin sensitivity, dependent on the rs4684847 risk allele that triggers PRRX1 binding. Thus, cross-species conservation analysis at the level of co-occurring TFBS provides a valuable contribution to the translation of genetic association signals to disease-related molecular mechanisms.

Effects of cooling on thyroid hormone secretion and growth of eastern bluebird (Sialia sialis) nestlings.

Achieving endothermic homeothermy is a critical aspect of avian development. In pre-homeothermic altricial nestlings, variation in parental brooding behavior results in variable exposure of nestlings to cooling, with consequences for the developing endocrine system. Nestlings facing repeated cooling challenges may benefit from upregulation of thyroid hormone secretion, allowing for earlier onset of thermoregulatory capability to mitigate the potentially negative effects of exposure to non-optimal temperatures during development. We examined the effects of (1) a single cooling challenge on thyroid hormone secretion in pre-homeothermic nestlings, and (2) repeated cooling challenges prior to the onset of homeothermy on nestling growth and thyroid hormone secretion prior to fledging. We found that pre-homeothermic eastern bluebird nestlings exposed to a single cooling challenge increased circulating triiodothyronine (T3), demonstrating that the thyroid system can be activated by cooling early in life. However, we found no consequences of repeated cooling during the first week of life on nestling growth or baseline T3 levels prior to fledging. This work addresses how the nestling hypothalamic-pituitary-thyroid axis responds to acute cooling challenges prior to the development of endothermic homeothermy; future work will confirm whether such responses allow nestlings to hasten the onset of physiological thermoregulation when conditions demand it.

Heterotopic ossification, osteolysis and implant failure following cervical total disc replacement with the M6-C™ artificial disc.

INTRODUCTION: A recent study reported a 34% mid-term revision rate after M6-C™ cervical total disc replacement (CTDR) for wear-related osteolysis. Here, we aim to investigate the prevalence, risk factors, and radiographic characteristics of periprosthetic bony changes and implant failure of the M6-C™ artificial disc. METHODS: We retrospectively analysed radiographic (conventional X-ray, CT scan) and clinical outcomes (EQ-5D-5L, Neck Disability Index (NDI), and Visual Analog Scale (VAS) for neck and arm pain) data collected during routine follow-up of patients who underwent CTDR with the M6-C™ between 2011 and 2015. RESULTS: In total, 85 patients underwent CTDR with the M6-C™. Follow-up data were available for 43 patients (54% female, mean age 44 years) with 50 implants and a mean follow-up of 8.1 years (6.5-11 years). Implant failure with the presence of severe osteolysis was identified in 5 (12%) patients who were all male (p = 0.016) and implanted at the C5/6 level (p = 0.11). All failed implants required revision surgery. The overall prevalence of osteolysis was 44% (22/50 implants) and 34% (17/50 implants) for significant heterotopic ossification. Patients with high-grade osteolysis showed higher VAS arm pain (p = 0.05) and lower EQ-5D-VAS health VAS (p = 0.03). CONCLUSION: We report a lower reoperation rate for failed M6-C™ implants than previously published, but confirmed that osteolysis and heterotopic ossification are common following CTDR with the M6-C™ and may be asymptomatic. Therefore, we strongly recommend ongoing clinical and radiographic monitoring after CTDR with the M6-C™, particularly for male patients implanted at the C5/6 level.

Insights into synthesis and function of KsgA/Dim1-dependent rRNA modifications in archaea.

Ribosomes are intricate molecular machines ensuring proper protein synthesis in every cell. Ribosome biogenesis is a complex process which has been intensively analyzed in bacteria and eukaryotes. In contrast, our understanding of the in vivo archaeal ribosome biogenesis pathway remains less characterized. Here, we have analyzed the in vivo role of the almost universally conserved ribosomal RNA dimethyltransferase KsgA/Dim1 homolog in archaea. Our study reveals that KsgA/Dim1-dependent 16S rRNA dimethylation is dispensable for the cellular growth of phylogenetically distant archaea. However, proteomics and functional analyses suggest that archaeal KsgA/Dim1 and its rRNA modification activity (i) influence the expression of a subset of proteins and (ii) contribute to archaeal cellular fitness and adaptation. In addition, our study reveals an unexpected KsgA/Dim1-dependent variability of rRNA modifications within the archaeal phylum. Combining structure-based functional studies across evolutionary divergent organisms, we provide evidence on how rRNA structure sequence variability (re-)shapes the KsgA/Dim1-dependent rRNA modification status. Finally, our results suggest an uncoupling between the KsgA/Dim1-dependent rRNA modification completion and its release from the nascent small ribosomal subunit. Collectively, our study provides additional understandings into principles of molecular functional adaptation, and further evolutionary and mechanistic insights into an almost universally conserved step of ribosome synthesis.

Cooling increases corticosterone deposition in feathers of eastern bluebird chicks.

Exposure to noxious stimuli early in life can both activate and shape the development of the hypothalamic-pituitary-adrenal (HPA) axis in birds and other vertebrates, with the potential for lifelong consequences. Studies assessing early HPA axis activation often rely on collection of blood samples to evaluate circulating glucocorticoid levels. However, blood sampling in small altricial young is invasive, limited by animal size, and not sufficient to provide detailed information about hormone exposure over protracted periods of time. We tested the use of feather corticosterone as an alternative method to assess HPA axis activity early in life in free-living, altricial chicks, for whom timing of growth of first feathers coincides with a period of rapid growth, development of the HPA axis, and reliance on parental care. We investigated (1) whether ecologically relevant bouts of experimental cooling prior to the onset of homeothermy-conditions known to elevate circulating corticosterone-are reflected in changes of feather corticosterone deposition in Eastern bluebird (Sialia sialis) chicks, and (2) whether such changes occurred in a sex-dependent manner. We found that cooling during the first week of life resulted in elevated feather corticosterone in first-grown feathers of experimentally cooled chicks relative to controls. The timing of deposition of corticosterone in feathers in response to temperature treatments was delayed in females compared to males. Results indicate that the hormone deposition in feather tissues of altricial nestlings reflects exposure to environmental stimuli, and can thus provide a minimally invasive tool for assessing HPA activity in early life. The development of the HPA axis, or its activation in response to environmental stimuli early in life, may also occur in a sex-dependent manner in altricial birds.

Chill out: Environmentally relevant cooling challenge does not increase telomere loss during early life.

In vertebrates, exposure to diverse stressors during early life activates a stress response that can initiate compensatory mechanisms or promote cellular damage with long-term fitness consequences. A growing number of studies associate exposure to stressors during early life with increased damage to telomeres (i.e., promoting the shortening of these highly conserved, repeating sequences of non-coding DNA at chromosome ends). However, some studies show no such relationship, suggesting that the nature, timing, and context of these challenges may determine the degree to which physiological mediators of the stress response act in a damage-mitigating or damage promoting way in relation to telomere dynamics. In free-living eastern bluebirds (Sialia sialis), we have previously demonstrated that bouts of offspring cooling that occur when brooding females leave the nest increase at least one such physiological mediator of the stress response (circulating glucocorticoids), suggesting that variation in patterns of maternal brooding may result in different impacts on telomere dynamics at a young age. Here we experimentally tested whether repeated bouts of ecologically relevant offspring cooling affected telomere dynamics during post-natal development. Rates of telomere shortening during the nestling stage were not affected by experimental cooling, but they were affected by brood size and the rate of growth during the nestling stage. Our data suggest that the effects of developmental stress exposure on offspring telomeres are often context-dependent and that not all challenges that increase physiological mediators of stress result in damage to telomeres. Under some conditions, physiological mediators of stress may instead act as protective regulators, allowing for optimization of fitness outcomes in the face of environmental challenges.

A versatile cis-acting element reporter system to study the function, maturation and stability of ribosomal RNA mutants in archaea.

General molecular principles of ribosome biogenesis have been well explored in bacteria and eukaryotes. Collectively, these studies have revealed important functional differences and few similarities between these processes. Phylogenetic studies suggest that the information processing machineries from archaea and eukaryotes are evolutionary more closely related than their bacterial counterparts. These observations raise the question of how ribosome synthesis in archaea may proceed in vivo. In this study, we describe a versatile plasmid-based cis-acting reporter system allowing to analyze in vivo the consequences of ribosomal RNA mutations in the model archaeon Haloferax volcanii. Applying this system, we provide evidence that the bulge-helix-bulge motif enclosed within the ribosomal RNA processing stems is required for the formation of archaeal-specific circular-pre-rRNA intermediates and mature rRNAs. In addition, we have collected evidences suggesting functional coordination of the early steps of ribosome synthesis in H. volcanii. Together our investigation describes a versatile platform allowing to generate and functionally analyze the fate of diverse rRNA variants, thereby paving the way to better understand the cis-acting molecular determinants necessary for archaeal ribosome synthesis, maturation, stability and function.

Deletion of Cdkn1b in ACI rats leads to increased proliferation and pregnancy-associated changes in the mammary gland due to perturbed systemic endocrine environment.

Mammary epithelial progenitors are the normal cell-of-origin of breast cancer. We previously defined a population of p27+ quiescent hormone-responsive progenitor cells in the normal human breast whose frequency associates with breast cancer risk. Here, we describe that deletion of the Cdkn1b gene encoding the p27 cyclin-dependent kinase inhibitor in the estrogen-induced mammary tumor-susceptible ACI rat strain leads to a decrease in the relative frequencies of Cd49b+ mammary luminal epithelial progenitors and pregnancy-related differentiation. We show by comprehensive gene expression profiling of purified progenitor and differentiated mammary epithelial cell populations that p27 deletion has the most pronounced effects on luminal progenitors. Cdkn1b-/- females have decreased fertility, but rats that are able to get pregnant had normal litter size and were able to nurse their pups implying that loss of p27 in ACI rats does not completely abrogate ovarian function and lactation. Reciprocal mammary gland transplantation experiments indicate that the p27-loss-induced changes in mammary epithelial cells are not only caused by alterations in their intrinsic properties, but are likely due to altered hormonal signaling triggered by the perturbed systemic endocrine environment observed in Cdkn1b-/- females. We also observed a decrease in the frequency of mammary epithelial cells positive for progesterone receptor (Pr) and FoxA1, known direct transcriptional targets of the estrogen receptor (Erα), and an increase in phospho-Stat5 positive cells commonly induced by prolactin (Prl). Characterization of genome-wide Pr chromatin binding revealed distinct binding patterns in mammary epithelial cells of Cdkn1b+/+ and Cdkn1b-/- females and enrichment in genes with known roles in Notch, ErbB, leptin, and Erα signaling and regulation of G1-S transition. Our data support a role for p27 in regulating the pool size of hormone-responsive luminal progenitors that could impact breast cancer risk.

[Interdisciplinary position paper: the value of radiofrequency denervation in the treatment of chronic pain]. / Interdisziplinäres Positionspapier: der Stellenwert der Radiofrequenzdenervierung in der Therapie chronischer Schmerzen.

Radiofrequency denervation has been established for many years as an important minimally invasive procedure for the treatment of chronic pain conditions. Positive experiences of many users for various indications are contrasted by a nonuniform evidence. With meticulous patient selection and correct assessment of the indications a longer term reduction of pain, a reduced need for analgesics and an improvement in the quality of life can be achieved. The aim of this interdisciplinary position paper is to present the value of radiofrequency denervation in the treatment of chronic pain. The summarized recommendations of the expert group are based on the available evidence and on the clinical experiences of Austrian centers that frequently implement the procedure. The position paper contains recommendations on patient selection and proven indications. We discribe safety aspects, complications, side effects and contraindications.

Initialization and Readout of Nuclear Spins via a Negatively Charged Silicon-Vacancy Center in Diamond.

In this Letter, we demonstrate initialization and readout of nuclear spins via a negatively charged silicon-vacancy (SiV) electron spin qubit. Under Hartmann-Hahn conditions the electron spin polarization is coherently transferred to the nuclear spin. The readout of the nuclear polarization is observed via the fluorescence of the SiV. We also show that the coherence time of the nuclear spin (6 ms) is limited by the electron spin-lattice relaxation due to the hyperfine coupling to the electron spin. This Letter paves the way toward realization of building blocks of quantum hardware with an efficient spin-photon interface based on the SiV color center coupled to a long lasting nuclear memory.

Upright MRI after decompression of spinal stenosis and concurrent spondylolisthesis.

OBJECTIVEThe treatment of patients with spinal stenosis and concurrent degenerative spondylolisthesis is controversial. Two large randomized controlled clinical trials reported contradictory results. The authors hypothesized that a substantial number of patients will show evidence of micro-instability after a sole decompression procedure.METHODSThis study was a retrospective analysis of all cases of lumbar spinal stenosis treated at the Frankfurt University Clinic (Universitätsklinik Frankfurt) from 2010 through 2013. Patients who had associated spondylolisthesis underwent upright MRI studies in flexion and extension for identification of subtle signs of micro-instability. Clinical outcome was assessed by means of SF-36 bodily pain (BP) and physical functioning (PF) scales.RESULTSA total of 21 patients were recruited to undergo upright MRI studies. The mean duration of follow-up was 65 months (SD 16 months). Of these 21 patients, 10 (47%) showed signs of micro-instability as defined by movement of > 4 mm on flexion/extension MRI. Comparison of mean SF-36 BP and PF scores in the group of patients who showed micro-instability versus those who did not showed no statistically significant difference on either scale.CONCLUSIONSThere seems to be a substantial subset of patients who develop morphological micro-instability after sole decompression procedures but do not experience any clinically significant effect of the instability.

Interactions of body temperature and nutritional status on hypothalamo-pituitary-adrenal axis activity in pre-thermoregulatory eastern bluebird chicks (Sialia sialis).

Early life experiences can affect the function of the hypothalamo-pituitary-adrenal (HPA) axis of vertebrates, with potential fitness consequences later in life. In altricial species, for example, variation in parental behavior, e.g. brooding or feeding, can modify the activity of the HPA axis of the young by altering their exposure to noxious stimuli as the young develop in the nest. We have shown that a drop in the body temperature of eastern bluebird (Sialia sialis) chicks, such as occurs when females are away from the nest, elevates their blood corticosterone levels. If repeated during the early days of their development, cooling bouts also reduce the chicks' later corticosterone secretion in response to handling. Thus, variation in maternal behavior has the capacity to shape the function of the chicks' HPA axis. To better understand how maternal absence from the nest activates the HPA axis of bluebird chicks, we experimentally mimicked the cooling that occurs when the female is away from the nest, and investigated a) the age at which the HPA axis becomes capable of responding to cooling by increasing corticosterone secretion, b) whether corticosterone secretion remains elevated throughout long periods of cooling, and c) whether fasting (also potentially associated with maternal absence) interacts with cooling to affect corticosterone secretion. Cooling for 18 min significantly elevated circulating corticosterone levels of chicks as young as 4 days post-hatch, indicating that their HPA axis is sensitive to cooling very early in life. Corticosterone levels remained elevated throughout longer bouts of cooling. However, a 1-hr period of fasting had no effect on corticosterone secretion, regardless of whether chicks were cooled or not. Collectively, these data demonstrate that variation in maternal brooding behavior can substantially modify the corticosterone profiles of chicks during early postnatal development, and that chick temperature is likely the main driver of this.

Interactive visual exploration and refinement of cluster assignments.

BACKGROUND: With ever-increasing amounts of data produced in biology research, scientists are in need of efficient data analysis methods. Cluster analysis, combined with visualization of the results, is one such method that can be used to make sense of large data volumes. At the same time, cluster analysis is known to be imperfect and depends on the choice of algorithms, parameters, and distance measures. Most clustering algorithms don't properly account for ambiguity in the source data, as records are often assigned to discrete clusters, even if an assignment is unclear. While there are metrics and visualization techniques that allow analysts to compare clusterings or to judge cluster quality, there is no comprehensive method that allows analysts to evaluate, compare, and refine cluster assignments based on the source data, derived scores, and contextual data. RESULTS: In this paper, we introduce a method that explicitly visualizes the quality of cluster assignments, allows comparisons of clustering results and enables analysts to manually curate and refine cluster assignments. Our methods are applicable to matrix data clustered with partitional, hierarchical, and fuzzy clustering algorithms. Furthermore, we enable analysts to explore clustering results in context of other data, for example, to observe whether a clustering of genomic data results in a meaningful differentiation in phenotypes. CONCLUSIONS: Our methods are integrated into Caleydo StratomeX, a popular, web-based, disease subtype analysis tool. We show in a usage scenario that our approach can reveal ambiguities in cluster assignments and produce improved clusterings that better differentiate genotypes and phenotypes.

Soft tissue substitutes in non-root coverage procedures: a systematic review and meta-analysis.

OBJECTIVES: The present systematic review compared the effectiveness of soft tissue substitutes (STSs) and autogenous free gingival grafts (FGGs) in non-root-coverage procedures to increase keratinized tissue (KT) width around teeth. MATERIALS AND METHODS: Included studies fulfilled the following main eligibility criteria: (a) preclinical in vivo or human controlled trials using FGG as control, (b) non-root-coverage procedures, and (c) assessment of KT width. Meta-analysis was performed on the gain in KT width (primary outcome variable) and several secondary variables. RESULTS: Eight human trials with short observation time evaluating five different STSs were identified. FGG yielded consistently significantly (p < 0.001) larger increase in KT width irrespective whether the comparison regarded an acellular matrix or a tissue-engineered STS. Further, FGG yielded consistently ≥2 mm KT width postoperatively, while use of STS did not, in the few studies reporting on this outcome. On the other hand, STSs resulted in significantly better aesthetic outcomes and received greater patient preference (p < 0.001). CONCLUSIONS: Based on relatively limited evidence, in non-root-coverage procedures, FGG (1) resulted consistently in significantly larger increase in KT width compared to STS and (2) yielded consistently ≥2 mm KT width postoperatively, while STSs did not. STSs yielded significantly better aesthetic outcomes, received greater patient preference, and appeared safe. CLINICAL RELEVANCE: Larger and more predictable increase in KT width is achieved with FGG, but STSs may be considered when aesthetics is important. Clinical studies reporting relevant posttreatment outcomes, e.g., postop KT width ≥2 mm, on the long-term (>6 months) are warranted.

Sedation for advanced procedures in the bronchoscopy suite: proceduralist or anesthesiologist?

PURPOSE OF REVIEW: This article focuses on the issue of sedation provided either by proceduralists or anesthesiologists for advanced bronchoscopy procedures. The relative merits of both approaches are presented. Current evidence from the literature and guideline recommendations relevant to this topic are reviewed. RECENT FINDINGS: In general, patient and proceduralist satisfaction as well as patient safety are increased when intravenous sedation is provided for advanced bronchoscopic procedures. However, guidelines by various societies remain vague on defining the appropriate level of care required when providing sedation for these procedures. In addition, targeted depth of sedation varies considerably among practitioners. While in some settings, nonanesthesiologist-administered propofol sedation has been proven safe; nevertheless, its use is controversial, especially in the bronchoscopy suite. SUMMARY: The role of the anesthesiologist in sedation for advanced bronchoscopy remains undefined. When deep sedation for prolonged interventional procedures is needed or when dealing with patients who have multiple comorbidities, an anesthesiologist should be involved.

First-rib stress fracture in two adolescent swimmers: a case report.

First-rib stress fractures have been described in adolescent athletes in various sports, with only one prior case report of first-rib stress fractures in an adolescent female swimmer. There is a need for research on the cause, management, and prevention of these injuries as they lead to significant morbidity and critical time away from sport for these aspiring athletes. We aimed to describe first-rib stress fractures as a potential cause for non-specific atraumatic chronic shoulder pain in adolescent swimmers and to discuss the different presentations, unique risk factors, treatment, and potential injury prevention strategies of such fractures. We discussed two such cases which were successfully treated with activity modification with restriction of all overhead activity, gradually progressive physical therapy and a return to swimming protocol. First-rib stress fractures can vary in presentation and should be in the differential diagnosis in adolescent swimmers with chronic shoulder pain. These injuries can be successfully managed with rest from overhead activities and physical therapy. Gradual return to competitive swimming can be achieved even with non-union of a first-rib stress fracture. Emphasis on balanced strength training in different muscle groups and proper swimming technique is essential to prevent these injuries.

Periimplantitis Treatment: Long-Term Comparison of Laser Decontamination and Implantoplasty Surgery.

PURPOSE: Periimplantitis is the most frequent cause of late implant failure; however, little is known about the long-term success of periimplantitis treatment and the effectiveness of various therapeutic interventions. MATERIALS AND METHODS: A total of 142 patients were referred to the Academy for Oral Implantology in Vienna for the treatment of recurrent periimplantitis around single-tooth implants. Of them, 72 patients (51%) were treated by laser decontamination, 47 patients (33%) by implantoplasty surgery, and 23 patients (16%) by a combination of both approaches. RESULTS: Overall success of periimplantitis therapy was 89% after 9 years of follow-up, and it did not differ significantly between female and male patients (P = 0.426). The number of implant failures that could not be prevented by periimplantitis treatment was 6 after laser decontamination (8%), 6 after implantoplasty surgery (13%), and 4 after a combination of both therapies (17%). Implant loss occurred after 4.9 ± 1.9 years of therapy, on average. No significant difference between the 3 treatment groups could be observed (P = 0.393). CONCLUSION: The present results suggest that success rates of periimplantitis therapy with either laser decontamination or surgical implantoplasty are high. These success rates do not appear to be associated with patient gender or treatment strategy.

Dysregulated expression of sterol O-acyltransferase 1 (Soat1) in the hair shaft of Hoxc13 null mice.

The cholesterol-metabolizing enzyme sterol O-acetyltransferase (SOAT1) is implicated in an increasing number of biological and pathological processes in a number of organ systems, including the differentiation of the hair shaft. While the functional and regulatory mechanisms underlying these diverse functional roles remain poorly understood, the compartment of the hair shaft known as medulla, affected by mutations in Soat1, may serve as a suitable model for defining some of these mechanisms. A comparative analysis of mRNA and protein expression patterns of Soat1/SOAT1 and the transcriptional regulator Hoxc13/HOXC13 in postnatal skin of FVB/NTac mice indicated co-expression in the most proximal cells of the differentiating medulla. This finding combined with the significant downregulation of Soat1 expression in postnatal skin of both Hoxc13 gene-targeted and transgenic mice based on previously reported DNA microarray results suggests a potential regulatory relationship between the two genes. Non-detectable SOAT1 expression in the defective hair follicle medulla of Hoxc13(tm1Mrc) mice and evidence for binding of HOXC13 to the Soat1 upstream control region obtained by ChIP assay suggests that Soat1 is a downstream regulatory target for HOXC13 during medulla differentiation.

Inter- and intra-observer agreement on Miller's classification of gingival tissue recessions.

Miller's is the most commonly used classification of gingival tissue recessions, defined as the displacement of the soft tissue margin apical to the cemento-enamel junction. However, data on the reliability of this classification are missing so far, although reliability, which reflects the consistency of repeated measurements, is regarded as a prerequisite for judging the utility of a classification. The aim of the present study was to evaluate inter- and intra-observer agreement on Miller's classification of gingival tissue recessions. Two hundred photographs (50 of each region: maxillary/mandibular anterior/posterior teeth) of gingival tissue recessions were evaluated twice by four observers with different degrees of experience in Miller's classification, gingival phenotype, tooth shape, and identifiability of the cemento-enamel junction. The following inter- and intra-observer agreements were found: Miller's classification, 0.72 and 0.73-0.95; gingival phenotype, 0.29 and 0.45-0.58; tooth shape, 0.39 and 0.44-0.59; and identifiability of the cemento-enamel junction, 0.21 and 0.30-0.59. A higher agreement was detected for anterior teeth. Further, gingival phenotype (thin-high scalloping) significantly correlated with tooth shape (long-narrow) (ρ = 0.662, p < 0.001). Miller's classification of gingival tissue recessions was evaluated by four examiners using 200 clinical photographs and yielded substantial to almost perfect agreement, with higher agreement for anterior teeth. Although limited to photographic assessment, the present study offers the so far missing proof on the sufficient inter- and intra-observer agreement of this classification.

[Anesthesiology in interventional pneumology- endoscopic interventions: part 1]. / Anästhesie in der interventionellen Pneumologie - Endoskopische Interventionen: Teil 1.

Less invasive bronchoscopic techniques for lung-volume-reduction have almost replaced surgical resections. Tracheobronchial obstructions and - to a certain degree - even bronchial tumors can be treated bronchoscopically. However all these procedures show specific risks anesthesiologists have to consider.