Gregor Johann Mendel and Modern Evolutionary Biology: Developmental genetics with model organisms

In Darwin’s and Mendel’s times, researchers investigated a wealth of organisms, chosen to solve particular problems for which they seemed especially well suited. Later, a focus on a few organisms, which are accessible to systematic genetic investigations, resulted in larger repertoires of methods and applications in these few species. Genetic animal model organisms with large research communities are the nematode Caenorhabditis elegans, the fly Drosophila melanogaster, the zebrafish Danio rerio, and the mouse Mus musculus. Due to their specific strengths, these model organisms have their strongest impacts in rather different areas of biology. C. elegans is unbeatable in the analysis of cell-to-cell contacts by saturation mutagenesis, as worms can be grown very fast in very high numbers. In Drosophila, a rich pattern is generated in the embryo as well as in adults that is used to unravel the underlying mechanisms of morphogenesis. The transparent larvae of zebrafish are uniquely suited to study organ development in a vertebrate, and the superb versatility of reverse genetics in the mouse made it the model organism to study human physiology and diseases. The combination of these models allows the in-depth genetic analysis of many fundamental biological processes using a plethora of different methods, finally providing many specific approaches to combat human diseases. The plant model Arabidopsis thaliana provides an understanding of many aspects of plant biology that might ultimately be useful for breeding crops.     

Intraductal papillomas of the breast: diagnosis and management of 151 patients

Introduction

The assessment of papillary lesions continues to be a challenging area in breast radiology and pathology. The management of intraductal papillomas without atypia of the breast remains controversial. The purpose of the present study was to determine diagnostic accuracy of radiographical diagnosis, core biopsy, and surgical excision in papillary breast lesions.

Material and methods

By using files from 1995 to 2010, 151 cases of intraductal papilloma with or without atypia were identified. Patients were stratified as follows: core biopsy followed by surgical excision (n = 61), core biopsy alone (n = 19), and surgical excision alone (n = 71).

Results

The upstage rate of intraductal papillomas without atypia on core biopsy to atypia or malignancy on excision was 8.9%. Excision specimens revealed intraductal papillomas without atypia in 68 out of 71 cases, and atypical papillomas in 3 cases.

Conclusion

Our findings suggest that radiographic and histopathological diagnosis of intraductal papillomas show high accuracy and good concordance. In cases where the radiographic diagnosis reveals suspicious lesions core biopsy represents the first choice.     

Elderly-onset rheumatoid arthritis

The treatment of elderly-onset rheumatoid arthritis pursues the same objectives as in younger patients: to control the clinical manifestations, to prevent structural damage, to preserve function, and to decrease excess mortality. In the elderly, the presence of co-morbidities and increased rate of drug-related adverse effects raise specific therapeutic challenges. Nonsteroidal anti-inflammatory drugs are associated with cardiovascular, gastrointestinal, and renal adverse events. The role for corticosteroid therapy remains controversial. Although glucocorticoids provide a short-term decrease in clinical activity and probably a medium-term decrease in structural damage, these benefits are offset by numerous adverse effects. Methotrexate was effective in clinical trials and observational studies and did not produce a higher adverse event rate compared to younger patients, provided renal function was normal. Data on the efficacy of TNFα antagonists in therapeutic trials are available only for etanercept. Disease activity decreased and function improved. The adverse event rate was higher in older patients, but this was also true of the conventional drugs used as comparators. Registry data confirm that TNFα antagonist therapy is effective in RA. An increased rate of infections was found only in some registries. To combat the 2-fold cardiovascular risk increase associated with RA, disease activity should be stringently controlled and all cardiovascular risk factors managed aggressively.     

Lenalidomide in combination with dexamethasone: effective regimen in patients with relapsed or refractory multiple myeloma complicated by renal impairment

Over the past decade, treatment options for patients with multiple myeloma (MM) have improved substantially, resulting in better response rates and prolonged overall survival (OS). Nevertheless, MM remains a challenging disease, especially if renal insufficiency (RI) or extensive pre-treatment aggravates the assignment of the optimal treatment schedule. In this retrospective study, we analyzed the outcome of lenalidomide plus dexamethasone in 167 patients with relapsed or refractory MM with focus on RI. The baseline creatinine clearance (CL_Cr) was normal in 94 patients (CL_Cr ≥ 80 ml/min), while RI was observed in 73 patients, including 40 patients with mild RI (50 ≤ CL_Cr < 80 ml/min) and 33 patients with moderate or severe RI (CL_Cr < 50 ml/min). Response rates declined depending on the severity of RI, being 67% among patients with normal kidney function, 60% among patients with mild RI and 49% among patients with moderate or severe RI. Time to progression (TTP) was significantly reduced in patients with severe RI and in case of >2 previous treatment lines. OS was not significantly different between patients with normal and impaired renal function. In contrast, the number of previous treatment lines (2 vs. <2) and the use of novel agents like bortezomib or thalidomide prior to lenalidomide plus dexamethasone therapy had a more adverse effect on OS. In conclusion, lenalidomide plus dexamethasone is an effective regimen for relapsed or refractory patients with MM complicated by RI with manageable toxicity.