Stochastic versus deterministic in haemopoiesis: what is what?

'Stochastic' models of haemopoiesis are discussed in juxtaposition to 'deterministic' concepts. It is argued that certain characteristic features attributed to stochastic models are conjectures, not supported by the observations quoted to provide an experimental basis: for example, an assumption of extrinsic control and another assumption that such control is inaccessible to external influences up to the very latest stages of cell development. Furthermore, it is argued that quantitative relationships between early progenitors (stem cells) and the number of colonies produced in vitro, cited as evidence supporting the proliferation and differentiation scheme of the stochastic model of random restriction, are also compatible with other models, providing that some sufficiently complex mechanism is involved in the control process. A simple model based on the principle of ordered development (usually denoted 'proliferation tree') is presented as an example and the calculated distributions are shown to have the same form as the experimental ones.     

Insulin in the brain what is its role?

Insulin and insulin receptors are present in brain and appear to function outside the realm of glucose homeostasis. Insulin receptors in the brain are structurally unique and appear to be found exclusively on neurons. Evidence from a variety of experimental systems indicates that insulin plays a role in neuronal growth and differentiation; additional functions may exist in the adult brain. Insulin action in neurons may be associated with unique signal transduction pathways.     

Determinism and liabilities in a complicated transrectal prostate biopsy: what is what

We report the case of a 53-year-old man suffering from the contemporary onset of penile Mondor's disease and high-flow priapism 10 days after a transrectal prostate biopsy. We analyzed whether these pathological conditions were causally related to the biopsy, and the role of urologist regarding the onset of one or both the diseases. Critically evaluating the clinical picture and the procedure used for the biopsy, we were able to recognize a connection between the office procedure and the onset of the high-flow priapism, otherwise than for penile Mondor's disease. Our report is of value for urologists, making them aware of such possible complications, and for forensic experts that might have to deal with similar cases, as it demonstrates only a partial involvement of urologist in this clinical setting.     

Molecular biology in cardiology: what is and where is the mutated gene?]

In this paper the role of molecular biology research and development in establishing etiology and pathogenesis of cardiovascular disease is discussed. Several examples of our own practice in the field (namely, Di George sequence, hereditary protein S deficiency, and hyperhomocysteinaemia) are provided as an illustration of the currently applied strategies.     

This is what COPD looks like

Despite decades of research, and the growing healthcare and societal burden of chronic obstructive pulmonary disease (COPD), therapeutic COPD breakthroughs have not occurred. Sub‐optimal COPD patient phenotyping, an incomplete understanding of COPD pathogenesis and a scarcity of sensitive tools that provide patient‐relevant intermediate endpoints likely all play a role in the lack of new, efficacious COPD interventions. In other words, COPD patients are still diagnosed based on the presence of persistent airflow limitation measured using spirometry. Spirometry measurements reflect the global sum of all the different possible COPD pathologies and perhaps because of this, we lose sight of the different contributions of airway and parenchymal abnormalities. With recent advances in thoracic X‐ray computed tomography (CT) and magnetic resonance imaging (MRI), lung structure and function abnormalities may be regionally identified and measured. These imaging endpoints may serve as biomarkers of COPD that can be used to better phenotype patients. Therefore, here we review novel CT and MRI measurements that help reveal COPD phenotypes and what COPD really ‘looks’ like, beyond spirometric indices. We discuss MR and CT imaging approaches for generating reproducible and sensitive measurements of COPD phenotypes related to pulmonary ventilation and perfusion as well as airway and parenchyma anatomical and morphological features. These measurements may provide a way to advance the development and testing of new COPD interventions and therapies.