Viral killer toxins induce caspase-mediated apoptosis in yeast

In yeast, apoptotic cell death can be triggered by various factors such as H2O2, cell aging, or acetic acid. Yeast caspase (Yca1p) and cellular reactive oxygen species (ROS) are key regulators of this process. Here, we show that moderate doses of three virally encoded killer toxins (K1, K28, and zygocin) induce an apoptotic yeast cell response, although all three toxins differ significantly in their primary killing mechanisms. In contrast, high toxin concentrations prevent the occurrence of an apoptotic cell response and rather cause necrotic, toxin-specific cell killing. Studies with Δyca1 and Δgsh1 deletion mutants indicate that ROS accumulation as well as the presence of yeast caspase 1 is needed for apoptosis in toxin-treated yeast cells. We conclude that in the natural environment of toxin-secreting killer yeasts, where toxin concentration is usually low, induction of apoptosis might play an important role in efficient toxin-mediated cell killing

SEX-RELATED DIFFERENCES IN THE PHARMACOLOGICAL TREATMENT OF MAJOR DEPRESSION - ARE WOMEN AND MEN TREATED DIFFERENTLY?

Background: In the last decade, sex-related medicine has become an increasingly important area of research as insights in this field can improve treatment strategies and recovery. The aim of this study was to investigate sex-related differences in the prescription and kinds of psychopharmacological treatment in individuals with unipolar affective disorder. Subjects and methods: Data collected on 388 patients attending a psychiatric rehabilitation clinic (194 females, 194 males, mean age 52.3 years, standard deviation 7.8 years), who were matched by age and severity of depression, were analyzed. Depression severity and information on drug type and quantity were assessed at the beginning of the rehabilitation program and compared between women and men. Results: A significant difference between females and males was found in the frequency of prescribing bupropion (females: 3.61%, males: 12.89%; p=0.001) and mirtazapine (females: 5.15%, males: 13.40%; p=0.005). In terms of polypharmacy, the results showed that over 53% of the patients were taking two or more psychotropic substances as a long-term therapy and that 34% of them were taking three to five different substances. No sex-related differences were found concerning the number of psychotropic drugs taken by the patients. Conclusion: The higher frequency of prescriptions for bupropion and mirtazapine in men might be explained by the adverse drug reactions of the drugs (e.g., fewer sexually adverse drug reactions, weight gain) and a known interaction with oral contraception. It remains unclear whether these aspects are taken into consideration for each patient in terms of their special needs and conditions or whether it is a decision based on the patient’s sex. Given a similar severity of depression, men and women are prescribed a similar number of psychotropic substances. However, the high number of psychotropic drugs prescribed on average should be noted. Well-trained healthcare professionals should focus on regularly assessing and optimizing treatment regimens

Predictive validity of the UK clinical aptitude test in the final years of medical school:a prospective cohort study

Peer reviewedPublisher PD

Stretching the Rules: Monocentric Chromosomes with Multiple Centromere Domains

The centromere is a functional chromosome domain that is essential for faithful chromosome segregation during cell division and that can be reliably identified by the presence of the centromere-specific histone H3 variant CenH3. In monocentric chromosomes, the centromere is characterized by a single CenH3-containing region within a morphologically distinct primary constriction. This region usually spans up to a few Mbp composed mainly of centromere-specific satellite DNA common to all chromosomes of a given species. In holocentric chromosomes, there is no primary constriction; the centromere is composed of many CenH3 loci distributed along the entire length of a chromosome. Using correlative fluorescence light microscopy and high-resolution electron microscopy, we show that pea (Pisum sativum) chromosomes exhibit remarkably long primary constrictions that contain 3-5 explicit CenH3-containing regions, a novelty in centromere organization. In addition, we estimate that the size of the chromosome segment delimited by two outermost domains varies between 69 Mbp and 107 Mbp, several factors larger than any known centromere length. These domains are almost entirely composed of repetitive DNA sequences belonging to 13 distinct families of satellite DNA and one family of centromeric retrotransposons, all of which are unevenly distributed among pea chromosomes. We present the centromeres of Pisum as novel ``meta-polycentric'' functional domains. Our results demonstrate that the organization and DNA composition of functional centromere domains can be far more complex than previously thought, do not require single repetitive elements, and do not require single centromere domains in order to segregate properly. Based on these findings, we propose Pisum as a useful model for investigation of centromere architecture and the still poorly understood role of repetitive DNA in centromere evolution, determination, and function

The second patient? Family members of cancer patients and their role in end-of-life decision making

Background: Family members are important companions of severely ill patients with cancer. However, studies about the desirability and difficulties of integrating relatives in the decision-making process are rare in oncology. This qualitative study explores the family role in decisions to limit treatment near the end of life from the professionals' point of view. Methods: Qualitative in-depth interviews were conducted with oncologists (n = 12) and nurses (n = 6) working at the Department of Hematology/Oncology at the University Hospital in Munich, Germany. The data were analyzed using a descriptive qualitative methodology and discussed from a medical ethics perspective. Results: Four major themes played a central role in the perception of the medical staff in regard to family members. (1) Family impact on patients' treatment preferences. (2) Strong family wish for further treatment. (3) Emotional distress of the family related to the involvement in end-of-life decision-making. (4) Importance of knowing family structures. Conclusions: The important role of the family members in patients' disease process is recognized by oncologists and oncology nurses. However, this does not seem to lead to an early involvement of the family members. Developing and establishing a systematic assessment of family members' needs and wishes in order to provide a specific-tailored support should become a priority for interdisciplinary clinical research in the near future