Healthcare resource utilization and associated costs among patients with migraine in Finland: A retrospective register-based study.

Migraine is a common chronic brain disorder, characterized by recurring and often disabling attacks of severe headache, with additional symptoms such as photophobia, phonophobia and nausea. Migraine affects especially the working age population. The objective of this retrospective observational register-based study was to analyze the use of healthcare services and associated costs in Finnish migraine patients. Study was based on aggregate data from January 1st, 2020, to December 31st, 2021, from the Finnish Institute for Health and Welfare's national registries. Patients were grouped into nine patient groups according to medication prescriptions and diagnoses. Healthcare resource utilization in specialty, primary, and occupational healthcare was assessed and analyzed separately for all-cause and migraine related healthcare contacts from a one-year period. The total number of patients was 175 711, and most (45%) of the patients belonged to a group that had used only one triptan. Migraine related total healthcare resource utilization was greater for patients that had used two or more triptans compared to those that had used only one. The patients with three or more preventive medications had the highest total migraine related healthcare resource utilization of the studied patient cohorts. Of the total annual healthcare costs 11.5% (50.6 million €) was associated to be migraine related costs. Total per patient per year healthcare costs were highest with patients that had used three or more preventive medications (5 626 €) and lowest in those with only one triptan (2 257 €). Our findings are in line with the recent European Headache Federation consensus statement regarding the unmet need in patients who have had inadequate response to two or more triptans. When assessing the patient access and cost-effectiveness of novel treatments for the treatment of migraine within different healthcare systems, a holistic analysis of the current disease burden along with potential gains for patients and healthcare service providers are essential information in guiding decision-making.

COVID-19 hospitalisations and all-cause mortality by risk group in Finland.

Ever since COVID-19 was announced as a global pandemic in March 2020, healthcare systems around the world have struggled with the burden of the disease. Vaccinations and other preventive measures have decreased this burden, but severe forms of COVID-19 leading to hospitalizations and even deaths still effect certain risk groups, such as the elderly and patients with multiple comorbidities. The objective of this retrospective observational study was to identify which risk groups are at the highest risk for a severe COVID-19 infection in Finland using national registry data ranging from January 2021 to June 2022. The data was analysed in three time periods, enabling comparisons in high-risk groups between epidemiological waves caused by different variants of SARS-CoV-2. The summary level data were stratified according to predefined groups based on two criteria: age (≥18 years, 18-59 years, and ≥60 years) and risk group. The results include analysis of infection hospitalisation rate (IHR), case fatality rate (CFR) and average length of stay (LOS) in both primary and specialty care for each risk group and age group. Our results confirm that despite the decrease in COVID-19 hospitalisations and deaths observed during the study period, a significant proportion of patients are still hospitalised, and deaths occur especially in the 60+ population. Also, even though the average length of stay of hospitalised COVID-19 patients has decreased, it is still long compared to specialty care hospitalisations in general. Old age is a significant risk factor for severe COVID-19 in all patient groups and certain risk factors such as chronic kidney disease clearly increase the risk for severe COVID-19 outcomes. Early treatment should be considered with a low threshold for risk group patients and for elderly patients in order to avoid severe disease courses, and to ease the burden on hospitals where resources are currently very strained.

Import of phosphatidylserine to and export of phosphatidylethanolamine molecular species from mitochondria.

Heavy isotope-labeled ethanolamine and serine as well as exogenous PE and PS species were used to study trafficking of phosphatidylethanolamine (PE) and -serine (PS) molecular species between the endoplasmic reticulum (ER) and mitochondria in HeLa cells. Import of both endogenous and exogenous PS to IMM was a relatively slow process (T1/2=several hours), but depended on the acyl chains. In particular, the 38:4 and 38:5 species were imported more efficiently compared to the other PS species. Knock-down of Mitofusin 2 or Mitostatin had no detectable effect on PS import to mitochondria, suggesting that the ER-mitochondria contacts regulated by these proteins are not essential. Knock-down of PS synthase 1 inhibited PS decarboxylation, suggesting that import of PS to mitochondria is coupled to its synthesis. Also the export of PE from IMM to microsomes is a relatively slow process, but again depends markedly on the acyl chain structure. Most notably, the polyunsaturated 38:4 and 38:5 PE species were less efficiently exported, which together with rapid import of the PS precursors most probably explains their enrichment in IMM. PE synthesized via the CDP-ethanolamine was also imported to IMM, but most of the PE in this membrane derives from imported PS. In contrast to PS, all PC species made in Golgi/ER translocated similarly and rapidly to IMM. In conclusion, selective translocation of PS species and PS-derived PE species between ER and mitochondria plays a major role in phospholipid homeostasis of these organelles.

Introduction of phospholipids to cultured cells with cyclodextrin.

Previous studies indicate that methyl-ß-cyclodextrin (meß-CD) can greatly enhance translocation of long-chain phospholipids from vesicles to cells in culture, which is very useful when studying, e.g., phospholipid metabolism and trafficking. However, the parameters affecting the transfer have not been systematically studied. Therefore, we studied the relevant parameters including meß-CD and vesicle concentration, incubation time, phospholipid structure, and cell type. Because meß-CD can extract cholesterol and other lipids from cells, thereby potentially altering cell growth or viability, these issues were studied as well. The results show that efficient incorporation of phospholipid species with hydrophobicity similar to that of natural species can be obtained without significantly compromising cell growth or viability. Cellular content of phosphatidyl-serine, -ethanolamine, and -choline could be increased dramatically, i.e., 400, 125, and 25%, respectively. Depletion of cellular cholesterol could be prevented or alleviated by inclusion of the proper amount of cholesterol in the donor vesicles. In summary, meß-CD mediates efficient transfer of long-chain (phospho) lipids from vesicles to cells without significantly compromising their growth or viability. This lays a basis for detailed studies of phospholipid metabolism and trafficking as well as enables extensive manipulation of cellular phospholipid composition, which is particularly useful when investigating mechanisms underlying phospholipid homeostasis.

Instrument-independent software tools for the analysis of MS-MS and LC-MS lipidomics data.

Mass spectrometry (MS), particularly electrospray-MS, is the key tool in modern lipidomics. However, as even a modest scale experiment produces a great amount of data, data processing often becomes limiting. Notably, the software provided with MS instruments are not well suited for quantitative analysis of lipidomes because of the great variety of species present and complexities in response calibration. Here we describe the use of two recently introduced software tools: lipid mass spectrum analysis (LIMSA) and spectrum extraction from chromatographic data (SECD), which significantly increase the speed and reliability of mass spectrometric analysis of complex lipidomes. LIMSA is a Microsoft Excel add-on that (1) finds and integrates the peaks in an imported spectrum, (2) identifies the peaks, (3) corrects the peak areas for overlap by isotopic peaks of other species and (4) quantifies the identified species using included internal standards. LIMSA is instrument-independent because it processes text-format MS spectra. Typically, the analysis of one spectrum takes only a few seconds.The SECD software allows one to display MS chromatograms as two-dimensional maps, which is useful for visual inspection of the data. More importantly, however, SECD allows one to extract mass spectra from user-defined regions of the map for further analysis with, e.g., LIMSA. The use of select regions rather than simple time-range averaging significantly improves the signal-to-noise ratio as signals outside the region of interest are more efficiently excluded. LIMSA and SECD have proven to be robust and convenient tools and are available free of charge from the authors.

Electrospray ionization mass spectrometry and exogenous heavy isotope-labeled lipid species provide detailed information on aminophospholipid acyl chain remodeling.

Mammalian cells maintain the phospholipid compositions of their different membranes remarkably constant. Beside de novo synthesis, degradation, and intracellular trafficking, acyl chain remodeling plays an important role in phospholipid homeostasis. However, many key details of this process remain unresolved, largely because of limitations of existing methodologies. Here we describe a novel approach that allows one to study metabolism of individual phospholipid species in unprecedented detail. Forty different phosphatidylethanolamine (PE) or -serine (PS) species with a deuterium-labeled head group were synthesized and introduced to BHK21 or HeLa cells using cyclodextrin-mediated transfer. Their metabolism was then monitored in detail by electrospray ionization mass spectrometry. Atypical PE and PS species were rapidly remodeled at both sn1 and sn2 position, yielding a molecular species profile similar to that the endogenous PE and PS. In contrast, remodeling of exogenous species identical or similar to major endogenous ones was more limited and much slower. Major differences in remodeling pathways and kinetics were observed between species within a class, as well as between corresponding PE and PS species. These data along with those obtained with pharmacological inhibitors strongly suggest that multiple lipid class-specific A-type phospholipases and acyl transferases are involved in aminophospholipid remodeling. In conclusion, the approach described here provides highly detailed information on remodeling of exogenously added (amino)glycerophospholipids and should thus be very helpful when elucidating the proteins and processes maintaining molecular species homeostasis.