20 research outputs found
Heart failure after pressure overload in autosomal-dominant desminopathies: Lessons from heterozygous DES-p.R349P knock-in mice
Background
Mutations in the human desmin gene (DES) cause autosomal-dominant and -recessive cardiomyopathies, leading to heart failure, arrhythmias, and AV blocks. We analyzed the
effects of vascular pressure overload in a patient-mimicking p.R349P desmin knock-in
mouse model that harbors the orthologue of the frequent human DES missense mutation p.
R350P.
Methods and results
Transverse aortic constriction (TAC) was performed on heterozygous (HET) DES-p.R349P
mice and wild-type (WT) littermates. Echocardiography demonstrated reduced left ventricular ejection fraction in HET-TAC (WT-sham: 69.5 ± 2.9%, HET-sham: 64.5 ± 4.7%, WTTAC: 63.5 ± 4.9%, HET-TAC: 55.7 ± 5.4%; p<0.01). Cardiac output was significantly
reduced in HET-TAC (WT sham: 13088 ± 2385 μl/min, HET sham: 10391 ± 1349μl/min,
WT-TAC: 8097 ± 1903μl/min, HET-TAC: 5793 ± 2517μl/min; p<0.01). Incidence and duration of AV blocks as well as the probability to induce ventricular tachycardias was highest in
HET-TAC. We observed reduced mtDNA copy numbers in HET-TAC (WT-sham: 12546 ± 406, HET-sham: 13526 ± 781, WT-TAC: 11155 ± 3315, HET-TAC: 8649 ± 1582; p = 0.025),
but no mtDNA deletions. The activity of respiratory chain complexes I and IV showed the
greatest reductions in HET-TAC.
Conclusion
Pressure overload in HET mice aggravated the clinical phenotype of cardiomyopathy and
resulted in mitochondrial dysfunction. Preventive avoidance of pressure overload/arterial
hypertension in desminopathy patients might represent a crucial therapeutic measure
Design, Construction, and Functional Characterization of a tRNA Neochromosome in Yeast
Here we report the design, construction and characterization of a tRNA neochromosome, a designer chromosome that functions as an additional, de novo counterpart to the native complement of Saccharomyces cerevisiae. Intending to address one of the central design principles of the Sc2.0 project, the ∼190 kb tRNA neochromosome houses all 275 relocated nuclear tRNA genes. To maximize stability, the design incorporated orthogonal genetic elements from non-S. cerevisiae yeast species. Furthermore, the presence of 283 rox recombination sites enable an orthogonal SCRaMbLE system capable of adjusting tRNA abundance. Following construction, we obtained evidence of a potent selective force once the neochromosome was introduced into yeast cells, manifesting as a spontaneous doubling in cell ploidy. Furthermore, tRNA sequencing, transcriptomics, proteomics, nucleosome mapping, replication profiling, FISH and Hi-C were undertaken to investigate questions of tRNA neochromosome behavior and function. Its construction demonstrates the remarkable tractability of the yeast model and opens up new opportunities to directly test hypotheses surrounding these essential non-coding RNAs
Design, construction, and functional characterization of a tRNA neochromosome in yeast
Here, we report the design, construction, and characterization of a tRNA neochromosome, a designer chromosome that functions as an additional, de novo counterpart to the native complement of Saccharomyces cerevisiae. Intending to address one of the central design principles of the Sc2.0 project, the ∼190-kb tRNA neochromosome houses all 275 relocated nuclear tRNA genes. To maximize stability, the design incorporates orthogonal genetic elements from non-S. cerevisiae yeast species. Furthermore, the presence of 283 rox recombination sites enables an orthogonal tRNA SCRaMbLE system. Following construction in yeast, we obtained evidence of a potent selective force, manifesting as a spontaneous doubling in cell ploidy. Furthermore, tRNA sequencing, transcriptomics, proteomics, nucleosome mapping, replication profiling, FISH, and Hi-C were undertaken to investigate questions of tRNA neochromosome behavior and function. Its construction demonstrates the remarkable tractability of the yeast model and opens up opportunities to directly test hypotheses surrounding these essential non-coding RNAs
Design, construction, and functional characterization of a tRNA neochromosome in yeast
Here, we report the design, construction, and characterization of a tRNA neochromosome, a designer chromosome that functions as an additional, de novo counterpart to the native complement of Saccharomyces cerevisiae. Intending to address one of the central design principles of the Sc2.0 project, the ∼190-kb tRNA neochromosome houses all 275 relocated nuclear tRNA genes. To maximize stability, the design incorporates orthogonal genetic elements from non-S. cerevisiae yeast species. Furthermore, the presence of 283 rox recombination sites enables an orthogonal tRNA SCRaMbLE system. Following construction in yeast, we obtained evidence of a potent selective force, manifesting as a spontaneous doubling in cell ploidy. Furthermore, tRNA sequencing, transcriptomics, proteomics, nucleosome mapping, replication profiling, FISH, and Hi-C were undertaken to investigate questions of tRNA neochromosome behavior and function. Its construction demonstrates the remarkable tractability of the yeast model and opens up opportunities to directly test hypotheses surrounding these essential non-coding RNAs
Microcalcification-associated breast cancer: presentation, successful first excision, long-term recurrence and survival rate
INTRODUCTION: In this study we evaluated mammographic, histological and immunohistochemical findings for microcalcification-associated breast cancer with regards to breast-conserving therapy, recurrence and survival rate.
PATIENTS AND METHODS: We retrospectively analyzed 99 consecutive, non-palpable and microcalcification-associated breast cancers (94 women) that were treated surgically between January 2002 and December 2003 at a national academic breast cancer center. Calcifications were classified according to the Breast Imaging Reporting and Data System (BI-RADS). Descriptors, surgical outcome and histological findings were assessed. Recurrences and survival rates were evaluated based on medical records, standardized patient questionnaires and/or contacting the physician.
RESULTS: 42 of the 99 lesions (42.4%) were invasive carcinomas, 57 (57.6%) were pure ductal carcinoma in situ (DCIS). 6 out of 99 (6.1%) lesions were triple negative, and 29 (29.3%) were HER2/neu positive. Successful first excision rate was 76/99 lesions (76.8%). Breast conservation was achieved in 73.7% (73/99). 10 women showed local recurrences without negatively impacting survival. The recurrences included round/punctate, amorphous, fine pleomorphic, and fine linear or fine-linear branching descriptors. The breast cancer-specific long-term survival rate was 91/94 (96.8%) for a mean follow-up of 81.4 months. The 3 patients who died due to breast carcinoma showed fine pleomorphic calcifications, and had nodal-positive invasive carcinoma at diagnosis.
CONCLUSION: Microcalcification-associated breast cancers are frequently treated with breast-conserving therapy. Continuous clinical and mammographic follow-up is recommended for all descriptors
[Prevention of cognitive decline in old age : Selected primary preventive approaches]
There are currently 1.8 million people in Germany affected by dementia. Despite advances in research and new treatments, there is no cure for most cases of dementia. The evidence regarding the prevention of cognitive decline in old age is unclear. In addition to the optimized adjustment of drug treatment (e.g., arterial hypertension and diabetes mellitus), preventive measures that can be influenced by individuals themselves play an important role. These include areas such as physical and cognitive activity, remedying hearing loss, sleep, social contacts, abstaining from alcohol as well as tobacco consumption and nutrition. Multimodal concepts and digital approaches appear to be promising and an increase in evidence is expected in the coming years
Prehabilitation in patients awaiting elective coronary artery bypass graft surgery – effects on functional capacity and quality of life: a randomized controlled trial
Objective: To determine the impact of an exercise-based prehabilitation (EBPrehab) program on preand postoperative exercise capacity, functional capacity (FC) and quality of life (QoL) in patients awaiting elective coronary artery bypass graft surgery (CABG).
Design: A two-group randomized controlled trail.
Setting: Ambulatory prehabilitation.
Subjects: Overall 230 preoperative elective CABG-surgery patients were randomly assigned to an intervention (IG, n=88; n=27 withdrew after randomization) or control group (CG, n=115).
Intervention: IG: two-week EBPrehab including supervised aerobic exercise. CG: usual care.
Main measures: At baseline (T1), one day before surgery (T2), at the beginning (T3) and at the end of cardiac rehabilitation (T4) the following measurements were performed: cardiopulmonary exercise test, six-minute walk test (6MWT), Timed-Up-and-Go Test (TUG) and QoL (MacNew questionnaire).
Results: A total of 171 patients (IG, n=81; CG, n=90) completed the study. During EBPrehab no complications occurred. Preoperatively FC (6MWTIG: 443.0±80.1m to 493.5±75.5m, P=0.003; TUGIG: 6.9±2.0 s to 6.1±1.8 s, P=0.018) and QoL (IG: 5.1±0.9 to 5.4±0.9, P<0.001) improved significantly more in IG compared to CG. Similar effects were observed postoperatively in FC (6MWDIG: Δ-64.7m, pT1–T3=0.013; Δ+47.2m, pT1–T4<0.001; TUGIG: Δ+1.4s, pT1–T3=0.003).
Conclusions: A short-term EBPrehab is effective to improve perioperative FC and preoperative QoL in patients with stable coronary artery disease awaiting CABG-surgery
Data-collection strategy for challenging native SAD phasing
Recent improvements in data-collection strategies have pushed the limits of native SAD (single-wavelength anomalous diffraction) phasing, a method that uses the weak anomalous signal of light elements naturally present in macromolecules. These involve the merging of multiple data sets from either multiple crystals or from a single crystal collected in multiple orientations at a low X-ray dose. Both approaches yield data of high multiplicity while minimizing radiation damage and systematic error, thus ensuring accurate measurements of the anomalous differences. Here, the combined use of these two strategies is described to solve cases of native SAD phasing that were particular challenges: the integral membrane diacylglycerol kinase (DgkA) with a low Bijvoet ratio of 1% and the large 200 kDa complex of the CRISPR-associated endonuclease (Cas9) bound to guide RNA and target DNA crystallized in the low-symmetry space group C2. The optimal native SAD data-collection strategy based on systematic measurements performed on the 266 kDa multiprotein/multiligand tubulin complex is discussed