Prediction of Recurrent Ischemic Stroke Using Registry Data and Machine Learning Methods: The Erlangen Stroke Registry.

BACKGROUND: There have been multiple efforts toward individual prediction of recurrent strokes based on structured clinical and imaging data using machine learning algorithms. Some of these efforts resulted in relatively accurate prediction models. However, acquiring clinical and imaging data is typically possible at provider sites only and is associated with additional costs. Therefore, we developed recurrent stroke prediction models based solely on data easily obtained from the patient at home. METHODS: Data from 384 patients with ischemic stroke were obtained from the Erlangen Stroke Registry. Patients were followed at 3 and 12 months after first stroke and then annually, for about 2 years on average. Multiple machine learning algorithms were applied to train predictive models for estimating individual risk of recurrent stroke within 1 year. Double nested cross-validation was utilized for conservative performance estimation and models' learning capabilities were assessed by learning curves. Predicted probabilities were calibrated, and relative variable importance was assessed using explainable artificial intelligence techniques. RESULTS: The best model achieved the area under the curve of 0.70 (95% CI, 0.64-0.76) and relatively good probability calibration. The most predictive factors included patient's family and housing circumstances, rehabilitative measures, age, high calorie diet, systolic and diastolic blood pressures, percutaneous endoscopic gastrotomy, number of family doctor's home visits, and patient's mental state. CONCLUSIONS: Developing fairly accurate models for individual risk prediction of recurrent ischemic stroke within 1 year solely based on registry data is feasible. Such models could be applied in a home setting to provide an initial risk assessment and identify high-risk patients early.

Albendazole reduces hepatic inflammation and endoplasmic reticulum-stress in a mouse model of chronic Echinococcus multilocularis infection.

BACKGROUND: Echinococcus multilocularis causes alveolar echinococcosis (AE), a rising zoonotic disease in the northern hemisphere. Treatment of this fatal disease is limited to chemotherapy using benzimidazoles and surgical intervention, with frequent disease recurrence in cases without radical surgery. Elucidating the molecular mechanisms underlying E. multilocularis infections and host-parasite interactions ultimately aids developing novel therapeutic options. This study explored an involvement of unfolded protein response (UPR) and endoplasmic reticulum-stress (ERS) during E. multilocularis infection in mice. METHODS: E. multilocularis- and mock-infected C57BL/6 mice were subdivided into vehicle, albendazole (ABZ) and anti-programmed death ligand 1 (αPD-L1) treated groups. To mimic a chronic infection, treatments of mice started six weeks post i.p. infection and continued for another eight weeks. Liver tissue was then collected to examine inflammatory cytokines and the expression of UPR- and ERS-related genes. RESULTS: E. multilocularis infection led to an upregulation of UPR- and ERS-related proteins in the liver, including ATF6, CHOP, GRP78, ERp72, H6PD and calreticulin, whilst PERK and its target eIF2α were not affected, and IRE1α and ATF4 were downregulated. ABZ treatment in E. multilocularis infected mice reversed, or at least tended to reverse, these protein expression changes to levels seen in mock-infected mice. Furthermore, ABZ treatment reversed the elevated levels of interleukin (IL)-1ß, IL-6, tumor necrosis factor (TNF)-α and interferon (IFN)-γ in the liver of infected mice. Similar to ABZ, αPD-L1 immune-treatment tended to reverse the increased CHOP and decreased ATF4 and IRE1α expression levels. CONCLUSIONS AND SIGNIFICANCE: AE caused chronic inflammation, UPR activation and ERS in mice. The E. multilocularis-induced inflammation and consecutive ERS was ameliorated by ABZ and αPD-L1 treatment, indicating their effectiveness to inhibit parasite proliferation and downregulate its activity status. Neither ABZ nor αPD-L1 themselves affected UPR in control mice. Further research is needed to elucidate the link between inflammation, UPR and ERS, and if these pathways offer potential for improved therapies of patients with AE.

Impact on Bile Acid Concentrations by Alveolar Echinococcosis and Treatment with Albendazole in Mice.

Alveolar echinococcosis (AE) caused by Echinococcus multilocularis is a chronic, progressive liver disease widely distributed in the Northern Hemisphere. The main treatment options include surgical interventions and chemotherapy with benzimidazole albendazole (ABZ). To improve the current diagnosis and therapy of AE, further investigations into parasite-host interactions are needed. This study used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to assess serum and liver tissue bile acid profiles in the i.p. chronic E. multilocularis-infected mouse model and evaluated the effects of the anthelmintic drug ABZ. Additionally, hepatic mRNA and protein expression of enzymes and transporters regulating bile acid concentrations were analyzed. AE significantly decreased unconjugated bile acids in serum and liver tissue. Taurine-conjugated bile salts were unchanged or increased in the serum and unchanged or decreased in the liver. Ratios of unconjugated to taurine-conjugated metabolites are proposed as useful serum markers of AE. The expression of the bile acid synthesis enzymes cytochrome P450 (CYP) 7A1 and aldo-keto reductase (AKR) 1D1 tended to decrease or were decreased in mice with AE, along with decreased expression of the bile acid transporters Na+/taurocholate cotransporting polypeptide (NTCP) and bile salt efflux pump (BSEP). Importantly, treatment with ABZ partially or completely reversed the effects induced by E. multilocularis infection. ABZ itself had no effect on the bile acid profiles and the expression of relevant enzymes and transporters. Further research is needed to uncover the exact mechanism of the AE-induced changes in bile acid homeostasis and to test whether serum bile acids and ratios thereof can serve as biomarkers of AE and for monitoring therapeutic efficacy.

The ratio of ursodeoxycholyltaurine to 7-oxolithocholyltaurine serves as a biomarker of decreased 11ß-hydroxysteroid dehydrogenase 1 activity in mouse.

BACKGROUND AND PURPOSE: 11ß-Hydroxysteroid dehydrogenase 1 (11ß-HSD1) regulates tissue-specific glucocorticoid metabolism and its impaired expression and activity are associated with major diseases. Pharmacological inhibition of 11ß-HSD1 is considered a promising therapeutic strategy. This study investigated whether alternative 7-oxo bile acid substrates of 11ß-HSD1 or the ratios to their 7-hydroxy products can serve as biomarkers for decreased enzymatic activity. EXPERIMENTAL APPROACH: Bile acid profiles were measured by ultra-HPLC tandem-MS in plasma and liver tissue samples of four different mouse models with decreased 11ß-HSD1 activity: global (11KO) and liver-specific 11ß-HSD1 knockout mice (11LKO), mice lacking hexose-6-phosphate dehydrogenase (H6pdKO) that provides cofactor NADPH for 11ß-HSD1 and mice treated with the pharmacological inhibitor carbenoxolone. Additionally, 11ß-HSD1 expression and activity were assessed in H6pdKO- and carbenoxolone-treated mice. KEY RESULTS: The enzyme product to substrate ratios were more reliable markers of 11ß-HSD1 activity than absolute levels due to large inter-individual variations in bile acid concentrations. The ratio of the 7ß-hydroxylated ursodeoxycholyltaurine (UDC-Tau) to 7-oxolithocholyltaurine (7oxoLC-Tau) was diminished in plasma and liver tissue of all four mouse models and decreased in H6pdKO- and carbenoxolone-treated mice with moderately reduced 11ß-HSD1 activity. The persistence of 11ß-HSD1 oxoreduction activity in the face of H6PD loss indicates the existence of an alternative NADPH source in the endoplasmic reticulum. CONCLUSIONS AND IMPLICATIONS: The plasma UDC-Tau/7oxo-LC-Tau ratio detects decreased 11ß-HSD1 oxoreduction activity in different mouse models. This ratio may be a useful biomarker of decreased 11ß-HSD1 activity in pathophysiological situations or upon pharmacological inhibition. LINKED ARTICLES: This article is part of a themed issue on Oxysterols, Lifelong Health and Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.16/issuetoc.

Twenty-Year Time Trends in Long-Term Case-Fatality and Recurrence Rates After Ischemic Stroke Stratified by Etiology.

BACKGROUND AND PURPOSE: Data on long-term survival and recurrence after stroke are lacking. We investigated time trends in ischemic stroke case-fatality and recurrence rates over 20-years stratified by etiological subtype according to the Trial of ORG 10172 in Acute Stroke Treatment classification within a population-based stroke register in Germany. METHODS: Data was collected within the Erlangen Stroke Project, a prospective, population-based stroke register covering a source population of 105 164 inhabitants (2010). Case fatality and recurrence rates for 3 months, 1 year, and 5 years were estimated with Kaplan-Meier estimates. Sex-specific time trends for case-fatality and recurrence rates were estimated with Cox regression. We adjusted for age, sex, and year of event and stratified for etiological subtypes. A sensitivity analysis with competing risk analysis for time trends in recurrence were performed. RESULTS: Between 1996 and 2015, 3346 patients with first ischemic stroke were included; age-standardized incidence per 100 000 was 75.8 in women and 131.6 in men (2015). Overall, 5-year survival probabilities were 50.4% (95% CI, 47.9-53.1) in women and 59.2% (95% CI, 56.4-62.0) in men; 5-year survival was highest in patients with first stroke due to small-artery occlusion (women, 71.8% [95% CI, 67.1-76.9]; men, 75.9% [95% CI, 71.3-80.9]) and lowest in cardioembolic stroke (women, 35.7% [95% CI, 31.0-41.1]; men, 47.8% [95% CI, 42.2-54.3]). Five-year recurrence rates were 20.1% (95% CI, 17.5-22.6) in women and 20.1% (95% CI, 17.5-22.7) in men; 5-year recurrence rate was lowest in women in stroke due to small artery occlusion 16.0% (95% CI, 11.7-20.1) and in men in large-artery atherosclerosis 16.6% (95% CI, 8.7-23.9); highest risk of recurrence was observed in undefined strokes (women, 22.3% [95% CI, 17.8-26.6]; men, 21.4% [95% CI, 16.7-25.9]). Cox regression revealed improvements in case-fatality rates over time with differences in stroke causes. No time trends in recurrence rates were observed. CONCLUSIONS: Long-term survival and recurrence varied substantially by first stroke cause. Survival probabilities improved over the past 2 decades; no major trends in stroke recurrence rates were observed.

Incidence and relative risk of stroke in the diabetic and the non-diabetic population between 1998 and 2014: A community-based stroke register.

One major objective of the St. Vincent Declaration was to reduce excess risk of stroke in people with diabetes mellitus. The aim of this study is to estimate the trend of incidence and relative risk of stroke in the diabetic and the non-diabetic populations in Germany over a 17-year period. We estimated age-sex standardised incidence rates of all stroke and ischaemic stroke in people with and without diabetes based on an ongoing prospective community-based stroke register covering 105,000 inhabitants. Time trends were analysed using Poisson regression. In total, 3,111 individuals (diabetes: 28.4%, men 46.9%, mean age 73.1 years (SD 13.2)) had a first stroke, 84.9% of which were ischaemic stroke. Among people with diabetes we observed a significant reduction in all stroke incidence by 1.5% per year (relative risk: 0.985; 95% confidence interval 0.972-0.9995) Likewise, this incidence tended to decrease for ischaemic stroke by 1% per year (0.993; 0.979-1.008). In contrast, the incidence rate for all stroke remained nearly stable among people without diabetes (1.003; 0.993-1.013) and for ischaemic stroke (1.002; 0.991-1.013). The relative risk comparing diabetic and non-diabetic population decreased for all stroke (two percent annual reduction) but not for ischaemic stroke. Time trends were similar for both sexes regarding all and ischaemic strokes. We found a reduction in risk of stroke in the diabetic population while this rate did not materially change in the non-diabetic population.

Marker-ion analysis for quantification of mucoadhesivity of microparticles in particle-retention assays.

The objective of the present work was to develop an improved method to quantify particle retention on mucosal tissue under dynamic flow conditions with simultaneous determination of drug dissolution. The principle was to dissolve the collected inert carrier material and quantify specific marker ions by reliable analytical methods. The mucoadhesive model particles consisted of drug-loaded porous calcium carbonate microcarriers coated with chitosan, and quantification of calcium ions by capillary electrophoresis enabled to determine particle-retention kinetics on colonic mucosal tissue. The method was validated by image analysis, and the particle-retention assay was successfully applied to granulate material (125-250 mm) and small particles (<90 µm) with mucoadhesive properties. Particle retention on colonic mucosa was improved by increasing the chitosan content, demonstrating the sensitivity and usefulness of marker-ion analysis for quantification of detached particles. Furthermore, we showed that drug dissolution from mucoadhesive microparticles followed comparable kinetics in the particle-retention assay and the standard USP IV method. Our findings are helpful for the development of micro-sized colonic drug delivery systems, in particular for optimization of mucoadhesive properties and sustained drug release kinetics of porous drug carriers.

Time trends in incidence of pathological and etiological stroke subtypes during 16 years: the Erlangen Stroke Project.

BACKGROUND: Population-based data, which continuously monitors time trends in stroke epidemiology are limited. We investigated the incidence of pathological and etiological stroke subtypes over a 16 year time period. METHODS: Data were collected within the Erlangen Stroke Project (ESPro), a prospective, population-based stroke register in Germany covering a total study population of 105,164 inhabitants (2010). Etiology of ischemic stroke was classified according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. RESULTS: Between January 1995 and December 2010, 3,243 patients with first-ever stroke were documented. The median age was 75 and 55% were females. The total stroke incidence decreased over the 16 year study period in men (Incidence Rate Ratio 1995-1996 vs. 2009-2010 (IRR) 0.78; 95% CI 0.58-0.90) but not in women. Among stroke subtypes, a decrease in ischemic stroke incidence (IRR 0.73; 95% CI 0.57-0.93) and of large artery atherosclerotic stroke (IRR 0.27; 95% CI 0.12-0.59) was found in men and an increase of stroke due to small artery occlusion in women (IRR 2.33; 95% CI 1.39-3.90). CONCLUSIONS: Variations in time trends of pathological and etiological stroke subtypes were found between men and women that might be linked to gender differences in the development of major vascular risk factors in the study population.