Correction: Greiner et al. Consecutive-Day Ventricular and Atrial Cardiomyocyte Isolations from the Same Heart: Shifting the Cost-Benefit Balance of Cardiac Primary Cell Research. Cells 2022, 11, 233.

In the original publication [...].

Consecutive-Day Ventricular and Atrial Cardiomyocyte Isolations from the Same Heart: Shifting the Cost-Benefit Balance of Cardiac Primary Cell Research.

Freshly isolated primary cardiomyocytes (CM) are indispensable for cardiac research. Experimental CM research is generally incompatible with life of the donor animal, while human heart samples are usually small and scarce. CM isolation from animal hearts, traditionally performed by coronary artery perfusion of enzymes, liberates millions of cells from the heart. However, due to progressive cell remodeling following isolation, freshly isolated primary CM need to be used within 4-8 h post-isolation for most functional assays, meaning that the majority of cells is essentially wasted. In addition, coronary perfusion-based isolation cannot easily be applied to human tissue biopsies, and it does not straightforwardly allow for assessment of regional differences in CM function within the same heart. Here, we provide a method of multi-day CM isolation from one animal heart, yielding calcium-tolerant ventricular and atrial CM. This is based on cell isolation from cardiac tissue slices following repeated (usually overnight) storage of the tissue under conditions that prolong CM viability beyond the day of organ excision by two additional days. The maintenance of cells in their near-native microenvironment slows the otherwise rapid structural and functional decline seen in isolated CM during attempts for prolonged storage or culture. Multi-day slice-based CM isolation increases the amount of useful information gained per animal heart, improving reproducibility and reducing the number of experimental animals required in basic cardiac research. It also opens the doors to novel experimental designs, including exploring same-heart regional differences.

Exploring the feasibility of new Dutch mental health policy within a large primary health care centre: a case study.

Background: A reform of Dutch mental health care aimed to substitute care from specialized care to general practice. Since 1 January 2014, Dutch general practitioners (GPs) are no longer allowed to refer patients without a psychiatric disorder to mental health care. Patients with non-complex psychological problems should be treated within general practice. Objective: To explore the feasibility of the Dutch mental health policy. Methods: We conducted an observational case study in a primary health care centre in 2014. The health care centre was a convenience sample; the participating GPs reorganized mental health care in line with the upcoming policy, and invited the researchers to monitor their referrals. We assessed how many patients with mental health problems (n = 408) were allocated to policy-concordant treatment. Additionally, 137 patients (33%) completed a follow up assessment on mental health problems 3 months after baseline. Results: The majority of the patients were allocated to treatment in line with the policy. Almost half of the patients (42%) were treated in a setting that was exactly policy-concordant, while the other half (47%) was treated in a setting that was even less specialized than was allowed. In general, patients showed improvement after 3 months, regardless of (non) policy-concordant treatment. Attrition rate after 3 months was high, probably due to the practical study design. Conclusion: There is potential for substitution of mental health care. Since the studied health care centre was specialized in mental health care, further research should explore if similar results can be found in other general practices.