Verantwoordelijkheid: De verantwoordelijkheid van de kascommissie

"Wie veel zegt, heeft veel te verantwoorden; ik zeg nooit meer dan ik verantwoorden kan; dat is niet verantwoord"

Abundance, size structure and community composition of phytoplankton in the Southern Ocean in the austral summer 1999/2000

The abundance, size structure and community composition of phytoplankton in the Southern Ocean were studied, using flow cytometry, microscopy and pigment profiles on two transects one latitudinal (N) and one longitudinal (W) during December 1999 and January 2000. In both transects, the concentration of autotrophic eukaryotes of 2-10μm equivalent spherical diameter (ESD) commonly exceeded those10μm ESD were detected by flow cytometry (however microscopy showed cells>10μm in length). Throughout transect N, chlorophyll α concentrations were generally. South of the Antarctic Polar Front (APF), chlorophyll α concentrations increased southward. CHEMTAX allocation of pigment data (italicized) showed that Diatoms contributed most chlorophyll with Haptophytes sub-dominant. North of the APF, chlorophyll α concentrations tended to increase northward. Here, Haptophytes contributed most chlorophyll, followed by Diatoms, Chlorophytes and Cyanobacteria, except at the northernmost stations where Cyanobacteria dominated. In transect W, chlorophyll α concentrations were also in most cases, but variable. Higher concentrations occasionally occurred in the west. In this transect, Diatoms contributed most (mean=61±15%) of the chlorophyll α, followed by Haptophytes. Nanodiatoms (particularly Fragilariopsis spp.) numerically dominated the diatom community. Fecal pellets composed of these nanodiatoms were observed in the Antarctic water, probably originating from heterotrophic dinoflagellates, implying a significant contribution of nanodiatoms to the microbial food web. However they contributed little to total chlorophyll α and diatom carbon biomass, particularly when chlorophyll and carbon concentrations were high

The 5T mouse multiple myeloma model: absence of c-myc oncogene rearrangement in early transplant generations.

Consistent chromosomal translocations involving the c-myc cellular oncogene and one of the three immunoglobin loci are typical for human Burkitt's lymphoma, induced mouse plasmacytoma (MPC) and spontaneously arising rat immunocytoma (RIC). Another plasma cell malignancy, multiple myeloma (MM), arising spontaneously in the ageing C57BL/KaLwRij mice, was investigated in order to see whether the MM cells contain c-myc abnormalities of the MPC or RIC type. Rearrangement of the c-myc oncogene was found in the bone marrow cells only in 5T2 MM transplantation line in a mouse of the 24th generation and in none of the seven other MM of the 5T series which were of earlier generations. Since the mouse 5T MM resembles the human MM very closely, including the absence of consistent structural c-myc oncogene abnormalities, it can serve as a useful experimental model for studies on the aetiopathogenesis of this disease

Perioperative outcome, long-term mortality and time trends in elderly patients undergoing low-, intermediate- or major non-cardiac surgery

Background: Decision-making whether older patients benefit from surgery can be a difficult task. This report investigates characteristics and outcomes of a large cohort of inpatients, aged 80 years and over, undergoing non-cardiac surgery. Methods: This observational study was performed at a tertiary university medical centre in the Netherlands. Patients of 80 years or older undergoing elective or urgent surgery from January 2004 to June 2017 were included. Outcomes were length of stay, discharge destination, 30-day and long-term mortality. Patients were divided into low-, intermediate and high-risk surgery subgroups. Univariable and multivariable logistic regression were used to evaluate the association of risk factors and outcomes. Secondary outcomes were time trends, assessed with Mantel–Haenszel chi-square test. Results: Data of 8251 patients, undergoing 19,027 surgical interventions were collected from the patients’ medical record. 7032 primary procedures were suitable for analyses. Median LOS was 3 days in the low-risk group, compared to six in the intermediate- and ten in the high-risk group. Median LOS of the total cohort decreased from 5.8 days (IQR 1.9–14.5) in 2004–2007 to 4.6 days (IQR 1.9–9.0) in 2016–2017. Three quarters of patients were discharged to their home. Postoperative 30-day mortality in the low-risk group was 2.3%. In the overall population 30-day mortality was high and constant during the study period (6.7%, ranging from 4.2 to 8.4%). Conclusion:Patients should not be withheld surgery solely based on their age. However, even for low-risk surgery, the mortality rate of more than 2% is substantial. Deciding whether older patients benefit from surgery should be based on the understanding of individual risks, patients’ wishes and a patient-centred plan.</p

Photoplethysmography and intracardiac pressures:early insights from a pilot study

Aims: Invasive haemodynamic monitoring of heart failure (HF) is used to detect deterioration in an early phase thereby preventing hospitalizations. However, this invasive approach is costly and presently lacks widespread accessibility. Hence, there is a pressing need to identify an alternative non-invasive method that is reliable and more readily available. In this pilot study, we investigated the relation between wrist-derived photoplethysmography (PPG) signals and the invasively measured pulmonary capillary wedge pressure (PCWP). Methods and results: Fourteen patients with aortic valve stenosis who underwent transcatheter aortic valve replacement with concomitant right heart catheterization and PPG measurements were included. Six unique features of the PPG signals [heart rate, heart rate variability, systolic amplitude (SA), diastolic amplitude, crest time (CT), and large artery stiffness index (LASI)] were extracted. These features were used to estimate the continuous PCWP values and the categorized PCWP (low &lt; 12mmHg vs. high ≥ 12mmHg). All PPG features resulted in regression models that showed low correlations with the invasively measured PCWP. Classification models resulted in higher performances: the model based on the SA and the model based on the LASI both resulted in an area under the curve (AUC) of 0.86 and the model based on the CT resulted in an AUC of 0.72. Conclusion: These results demonstrate the capability to non-invasively classify patients into clinically meaningful categories of PCWP using PPG signals from a wrist-worn wearable device. To enhance and fully explore its potential, the relationship between PPG and PCWP should be further investigated in a larger cohort of HF patients.</p

Photoplethysmography and intracardiac pressures:early insights from a pilot study

Aims: Invasive haemodynamic monitoring of heart failure (HF) is used to detect deterioration in an early phase thereby preventing hospitalizations. However, this invasive approach is costly and presently lacks widespread accessibility. Hence, there is a pressing need to identify an alternative non-invasive method that is reliable and more readily available. In this pilot study, we investigated the relation between wrist-derived photoplethysmography (PPG) signals and the invasively measured pulmonary capillary wedge pressure (PCWP). Methods and results: Fourteen patients with aortic valve stenosis who underwent transcatheter aortic valve replacement with concomitant right heart catheterization and PPG measurements were included. Six unique features of the PPG signals [heart rate, heart rate variability, systolic amplitude (SA), diastolic amplitude, crest time (CT), and large artery stiffness index (LASI)] were extracted. These features were used to estimate the continuous PCWP values and the categorized PCWP (low &lt; 12mmHg vs. high ≥ 12mmHg). All PPG features resulted in regression models that showed low correlations with the invasively measured PCWP. Classification models resulted in higher performances: the model based on the SA and the model based on the LASI both resulted in an area under the curve (AUC) of 0.86 and the model based on the CT resulted in an AUC of 0.72. Conclusion: These results demonstrate the capability to non-invasively classify patients into clinically meaningful categories of PCWP using PPG signals from a wrist-worn wearable device. To enhance and fully explore its potential, the relationship between PPG and PCWP should be further investigated in a larger cohort of HF patients.</p

Ebstein’s anomaly may be caused by mutations in the sarcomere protein gene MYH7

Ebstein's anomaly is a rare congenital heart malformation characterised by adherence of the septal and posterior leaflets of the tricuspid valve to the underlying myocardium. Associated abnormalities of left ventricular morphology and function including left ventricular noncompaction (LVNC) have been observed. An association between Ebstein's anomaly with LVNC and mutations in the sarcomeric protein gene MYH7, encoding β-myosin heavy chain, has been shown by recent studies. This might represent a specific subtype of Ebstein's anomaly with a Mendelian inheritance pattern. In this review we discuss the association of MYH7 mutations with Ebstein's anomaly and LVNC and its implications for the clinical care for patients and their family members.Congenital Heart Diseas