Lars Söderström

The Ecology of Dispersal in Relation to Conservation

Small populations easily become extinct (Goodman, 1987). Small populations may also be affected by genetic drift and inbreeding (Schonewald Cox et al, 1983), although the importance of these latter effects on population dynamics is less clear (Ehrlich, 1983; Shaffer, 1987; see also chapter 4). The adverse demographic and genetic processes in small populations are both counteracted by immigration. Such immigration should keep the density over a certain threshold level (Brown & Kodric–Brown, 1977) or supply at least one reproducing individual per generation (Schonewald–Cox et al., 1983) to circumvent extinction or loss of genetic variability. However, immigration of foreign competing or predating species may have negative effects on local and circumscribed communities (Helle & Jarvinen, 1986).

Spore establishment probability and the persistence of the fugitive invading moss, Orthodontium lineare : a spatial simulation model

Spore establishment probability and the persistence of the fugitive invading moss, Orthodontium lineare : a spatial simulation model

Which habitat parameters are most important for the persistence of a bryophyte species on patchy, temporary substrates?

The effects of changes in habitat parameters important for conservation (abundance and size of habitats and distance between them) on both short-lived fugitive and long-lived resident bryophyte species was studied. Persistence of a species in a system of temporary and patchily distributed habitats was simulated both for stable and fluctuating environments. The values of the parameters in the model were derived from estimates made in two colonist species, Orthodontium lineare and Ptilidium pulcherrimum. Persistence of a resident species is much more enhanced by variable environment that persistence of a fugitive species. Both species are also more often limited with regard to dispersal/establishment in variable environments, especially the resident species. Reducing the habitat parameters (decreased area, fewer localities/substrate patches and increased distance between them) generally results in lower persistence of the species. In variable environments, fugitive species are more sensitive than the resident species to reduction of any of the habitat parameters. Both fugitive and resident species are most sensitive to reduced habitat density (i.e. to increased distance between available patches). Increased isolation of habitat patches is therefore concluded to be the most serious effect of habitat fragmentation.

Bryophyte conservation for the future

Abstract The conservation process involves recognizing and listing rare and decreasing species, recording their distribution, biology and specific threats, proposing conservation programmes, and executing these programmes. There are large gaps in our knowledge about bryophytes which must be filled before their conservation can be selective. These include taxonomy, bryogeography, habitat demands, natural dynamics, dispersal ability, population structure and genetics. In a long-term perspective, conservation must strive towards creating possibilities for the species to survive without too much artificial support. It is particularly important to focus on habitats and sites where the species may survive naturally during unfavourable periods. In the short term, creating nature reserves with large populations can save a species until our knowledge has increased. In practice, bryologists must be more active in collecting data and informing the conservation organizations and governmental authorities about the need for conservation.

Premonitory symptoms in migraine : a cross-sectional study in 2714 persons

Aim To describe the frequency and number of premonitory symptoms (PS) in migraine, the co-occurrence of different PS, and their association with migraine-related factors. Methods In this cross-sectional study, a validated questionnaire was sent to Finnish migraine families between 2002 and 2013 to obtain data on 14 predefined PS, migraine diagnoses, demographic factors, and migraine characteristics. The estimated response rate was 80%. Results Out of 2714 persons, 2223 were diagnosed with migraine. Among these, 77% reported PS, with a mean number of 3.0 symptoms compared to 30% (p < 0.001) and 0.5 symptoms (p < 0.001) among 491 persons with non-migraine headaches. Yawning was the most commonly reported symptom (34%) among migraineurs. Females reported PS more frequently than males (81 versus 64%, p < 0.001) and experienced a higher number of different symptoms (mean 3.3 versus 1.8, p < 0.001). All measures of migraine severity were associated with a higher burden of PS. Light and sound sensitivity showed the highest co-occurrence (kappa = 0.51, 95% CI 0.47–0.55). In a generalized linear model, age, gender, higher frequency, duration and intensity of headache, reduced working capacity, most aura symptoms, and associated symptoms of the headache phase were significantly associated with an increased in the number of PS. Conclusion PS are experienced by a majority of migraineurs. More severe migraine is associated with a higher burden of PS. Since the material was not entirely representative of the general population of migraineurs, caution should be exercised in generalizing the results.

Reduced inflammation in relapsing-remitting multiple sclerosis after therapy switch to rituximab

Objective: To describe the effects of switching treatment from ongoing first-line injectable therapies to rituximab on inflammatory activity measured by MRI and levels of CSF neurofilament light chain (CSF-NFL) in a cohort of patients with clinically stable relapsing-remitting multiple sclerosis (RRMS). Method: Seventy-five patients with clinically stable RRMS treated with the first-line injectables interferon-β (IFN-β) and glatiramer acetate (GA) at 3 Swedish centers were switched to rituximab in this open-label phase II multicenter study. After a run-in period of 3 months, 2 IV doses of 1,000 mg rituximab were given 2 weeks apart followed by repeated clinical assessment, MRI, and CSF-NFL for 24 months. Results: The mean cumulated number of gadolinium-enhancing lesions per patient at months 3 and 6 after treatment shift to rituximab was reduced compared to the run-in period (0.028 vs 0.36, p = 0.029). During the first year after treatment shift, the mean number of new or enlarged T2 lesions per patient was reduced (0.01 vs 0.28, p = 0.004) and mean CSF-NFL levels were reduced by 21% (p = 0.01). Conclusions: For patients with RRMS, a treatment switch from IFN or GA to rituximab is associated with reduced inflammatory activity measured by MRI and CSF-NFL. Classification of evidence: This study provides Class IV evidence that rituximab has an equal or superior effect in reducing inflammatory activity in RRMS measured by MRI and CSF-NFL compared to first-line injectables during the first year after treatment shift.

Nurse-Led, Telephone-Based, Secondary Preventive Follow-Up after Stroke or Transient Ischemic Attack Improves Blood Pressure and LDL Cholesterol : Results from the First 12 Months of the Randomized, Controlled NAILED Stroke Risk Factor Trial

Background Enhanced secondary preventive follow-up after stroke or transient ischemic attack (TIA) is necessary for improved adherence to recommendations regarding blood pressure (BP) and low-density lipoprotein cholesterol (LDL-C) levels. We investigated whether nurse-led, telephone-based follow-up was more efficient than usual care at improving BP and LDL-C levels at 12 months after hospital discharge. Methods We randomized 537 patients to either nurse-led, telephone-based follow-up (intervention) or usual care (control). BP and LDL-C measurements were performed at 1 month (baseline) and 12 months post-discharge. Intervention group patients who did not meet target values at baseline received additional follow-up, including titration of medication and lifestyle counselling, to reach treatment goals (BP < 140/90 mmHg, LDL-C < 2.5 mmol/L). Results At 12 months, mean systolic BP, diastolic BP and LDL-C was 3.3 (95% CI 0.3 to 6.3) mmHg, 2.3 mmHg (95% CI 0.5 to 4.2) and 0.3 mmol/L (95% CI 0.1 to 0.4) lower in the intervention group compared to controls. Among participants with values above the treatment goal at baseline, the difference in systolic BP and LDL-C was more pronounced (8.0 mmHg, 95% CI 4.0 to 12.1, and 0.6 mmol/L, 95% CI 0.4 to 0.9). A larger proportion of the intervention group reached the treatment goal for systolic BP (68.5 vs. 56.8%, p = 0.008) and LDL-C (69.7% vs. 50.4%, p < 0.001). Conclusions Nurse-led, telephone-based secondary preventive follow-up, including medication adjustment, was significantly more efficient than usual care at improving BP and LDL-C levels by 12 months post-discharge. Trial Registration ISRCTN Registry ISRCTN23868518

Implementation of Telephone-Based Secondary Preventive Intervention after Stroke and Transient Ischemic Attack - Participation Rate, Reasons for Nonparticipation and One-Year Mortality

Background and Purpose: Patients who experience a stroke or transient ischemic attack (TIA) are known to be at high risk of subsequent vascular events, underscoring the need for secondary preventive intervention. However, previous studies have indicated insufficiency in the implementation of secondary prevention, emphasizing the need to develop effective methods of follow-up. In the present study, we examined the potential of implementing a telephone-based, nurse-led, secondary preventive follow-up in stroke and TIA patients on a population level by analyzing the participation rate, reasons for nonparticipation, and one-year mortality. Methods: Between January 1, 2010 and December 31, 2011, all patients admitted to Östersund hospital, Sweden, and diagnosed with either stroke or TIA were considered for inclusion into the secondary preventive follow-up. Baseline data were collected at the hospital, and reasons for nonparticipation were documented. Multivariate logistic regression was performed to identify predictors of the patient decision not to participate and to explore independent associations between baseline characteristics and exclusion. A one-year follow-up of mortality was also performed; the survival functions of the three groups (included, excluded, declining participation) was calculated using the Kaplan-Meier estimator. Results: From a total of 810 identified patients, 430 (53.1%) were included in the secondary preventive follow-up, 289 (35.7%) were excluded mainly due to physical or cognitive disability, and 91 (11.2%) declined participation. Age ≥85 years, ischemic and hemorrhagic stroke, modified Rankin scale score >3, body mass index ≥25, congestive heart failure, and lower education level were independently associated with exclusion, whereas lower education level was the only factor independently associated with the patient decision not to participate. Exclusion was associated with a more than 12 times higher risk of mortality within the first year after discharge. Conclusion: Population-based implementation of secondary prevention in stroke and TIA patients is limited by the high prevalence of comorbidity and a considerable degree of disability. In our study, a large proportion of patients were unable to participate even in this simple form of secondary preventive follow-up. Exclusion was associated with substantially higher one-year mortality, and education level was independently associated with physical ability as well as the motivation to participate in the secondary preventive follow-up program.

Improved treatment satisfaction after switching therapy to rituximab in relapsing-remitting MS.

Objective: New disease-modifying treatment strategies in multiple sclerosis offer possibilities for individualised treatment. In this study, we evaluated patient-reported outcome measures before and after a switch in therapy from first-line injectable treatments to rituximab. Method: A total of 75 patients with clinically stable relapsing–remitting multiple sclerosis (RRMS) receiving ongoing first-line injectable treatment at three Swedish centres had their treatment switched to rituximab in this open-label phase II multicentre study. Assessment of treatment satisfaction, patient-perceived impact of the disease on daily life, fatigue, cognitive symptoms and disease progression was performed 3 months before and at the time of the treatment shift and then for a subsequent 2-year period. Results: The overall treatment satisfaction rating improved significantly from a mean of 4.8 (scale range: 1–7), while on injectable therapies, to a mean of 6.3 after 1 year of rituximab treatment (p < 0.001). This improvement was sustained after 2 years. There was no significant change in scores for patient-perceived impact of disease, fatigue or disease progression. Conclusion: A shift in therapy from first-line injectables to rituximab in a cohort of clinically stable RRMS patients was followed by improved treatment satisfaction. This is clinically relevant as it may influence long-term adherence to immunomodulating therapy.

Risk of Ischemic Stroke After an Acute Myocardial Infarction in Patients With Diabetes Mellitus

Background—Incidence, any trend over time, and predictors of ischemic stroke after an acute myocardial infarction (AMI) in diabetic patients are unknown. Methods and Results—Data for 173 233 unselected patients with an AMI, including 33 503 patients with diabetes mellitus, were taken from the Swedish Register of Information and Knowledge about Swedish Heart Intensive Care Admissions (RIKS-HIA) during 1998 to 2008. Ischemic stroke events were recorded during 1 year of follow-up. Patients with diabetes mellitus more often had a history of cardiovascular disease, received less reperfusion therapy, and were treated with acetylsalicylic acid, P2Y12 inhibitors, and statins to a lesser extent compared with patients without diabetes mellitus. However, the use of evidence-based therapies increased markedly in both groups during the study period. The incidence of ischemic stroke during the first year after AMI decreased from 7.1% to 4.7% in patients with diabetes mellitus and from 4.2% to 3.7% in patients without diabetes mellitus. Risk reduction was significantly larger in the diabetic subgroup. Reperfusion therapy, acetylsalicylic acid, P2Y12 inhibitors, and statins were independently associated with the reduced stroke risk. Conclusions—Ischemic stroke is a fairly common complication after an AMI in patients with diabetes mellitus, but the risk of stroke has decreased during recent years. The increased use of evidence-based therapies contributes importantly to this risk reduction, but there is still room for improvement.