Some young adults can maintain good oral health despite socioeconomic challenges.

The association between dental caries experience and socioeconomic status, as reflected in income and educational level, is well known. However, some individuals maintain good health despite socioeconomic disadvantage. The aim of this qualitative study was to explore salutogenic (health-promoting) factors among healthy caries-free young adults of low socioeconomic status. Seventeen participants (11 women), 19-23 years of age, who were caries-free and of low socioeconomic status were interviewed in-depth. The interviews were transcribed verbatim and analysed using qualitative content analysis with an inductive approach. The theme revealed was 'Building trust and shifting responsibility from parent to child throughout children's development lays the salutogenic foundation for oral health', comprising three categories: (i) a basis for health; (ii) creating one's own path by testing wings; and (iii) developing resources for health. A feeling of trust was expressed, participants were confident in the unconditional support of their caregivers, and caregivers were trusting participants to be able to take control over their own oral health. Health-promotive factors were established not only by instilling healthy habits during childhood, but also by parental guidance through adolescence, enabling young adults to develop resources and assets to take control over their own health independently.

[Dental caries - the most common noncommunicable disease and its impact on general health and disease]. / Karies ­ världens vanligaste icke smittsamma sjukdom.

More than 2.8 billion individuals worldwide suffer from untreated caries. Over ninety-five percent of all 50-year-olds in Sweden have caries experience. Caries is the most common cause of dental restorations and tooth loss. Tooth loss is associated with cardiovascular diseases, dementia, and death. Periapical tooth infections caused by caries can spread and cause severe infection, however rarely with lethal outcome. Sugars are a common risk factor for caries and other noncommunicable diseases such as cardiovascular diseases, diabetes, and obesity.  Caries is a consequence of sugar-provoked acid production and dysbiosis in the tooth biofilm (dental plaque). There are several conditions which may increase the risk for dental caries, such as different medical conditions and medications which may cause dry mouth. Treatment costs for caries are high.

Exposure to phenoxyacetic acids and glyphosate as risk factors for non-Hodgkin lymphoma- pooled analysis of three Swedish case-control studies including the sub-type hairy cell leukemia.

The association between pesticide exposure and non-Hodgkin lymphoma (NHL) including hairy cell leukemia (HCL) was analyzed in a pooled study of three case-control studies. Results on exposure to pesticides were based on 1,425 cases and 2,157 controls participating in the studies. Exposures were assessed by self-administered questionnaires completed as needed by phone. In the pooled univariate analyses adjusted by age, gender and year of diagnosis, exposure to herbicides of the phenoxyacetic acid type yielded statistically significant increased risk with odds ratio (OR) = 1.9, 95% confidence interval CI) = 1.4-2.5. The herbicide glyphosate gave OR = 2.2, 95% CI = 1.3-3.8. Impregnating agents increased the risk. No clear dose-response effect was seen. OR was highest in the >10-20 years latency group for herbicides and impregnating agents. In the multivariate analysis including main pesticide groups, statistically significant increased risk was found for herbicides, OR = 1.6, 95% CI = 1.2-2.1 and impregnating agents with OR = 1.4, 95% CI = 1.1-1.8. This analysis confirmed an association between NHL including HCL and exposure to certain herbicides.

Common resilience factors among healthy individuals exposed to chronic adversity: a systematic review.

OBJECTIVE: To identify common resilience factors against non-communicable diseases (dental caries, diabetes type II, obesity and cardiovascular disease) among healthy individuals exposed to chronic adversity. MATERIALS AND METHODS: The databases MEDLINE (via PubMed), Scopus and CINAHL were searched. Observational studies in English assessing resilience factors among populations living in chronic adversity were included. Intervention studies, systematic reviews, non-original articles and qualitative studies were excluded. There were no restrictions regarding publication year or age. No meta-analysis could be done. Quality assessments were made with the Newcastle-Ottawa scale (NOS). RESULTS: A final total of 41 studies were included in this systematic review. The investigated health resilience factors were divided into the following domains: environmental (community and family) and individual (behavioural and psychosocial). A narrative synthesis of the results was made according to the domains. CONCLUSIONS: Individual psychosocial, family and environmental factors play a role as health resilience factors in populations living in chronic adversity. However, the inconclusive results suggest that these factors do not act in isolation but interplay in a complex manner and that their interaction may vary during the life course, in different contexts, and over time.

Temporal and spatial changes in benthic invertebrate trophic networks along a taxonomic richness gradient.

Species interactions underlie most ecosystem functions and are important for understanding ecosystem changes. Representing one type of species interaction, trophic networks were constructed from biodiversity monitoring data and known trophic links to assess how ecosystems have changed over time. The Baltic Sea is subject to many anthropogenic pressures, and low species diversity makes it an ideal candidate for determining how pressures change food webs. In this study, we used benthic monitoring data for 20 years (1980-1989 and 2010-2019) from the Swedish coast of the Baltic Sea and Skagerrak to investigate changes in benthic invertebrate trophic interactions. We constructed food webs and calculated fundamental food web metrics evaluating network horizontal and vertical diversity, as well as stability that were compared over space and time. Our results show that the west coast of Sweden (Skagerrak) suffered a reduction in benthic invertebrate biodiversity by 32% between the 1980s and 2010s, and that the number of links, generality of predators, and vulnerability of prey have been significantly reduced. The other basins (Bothnian Sea, Baltic Proper, and Bornholm Basin) do not show any significant changes in species richness or consistent significant trends in any food web metrics investigated, demonstrating resilience at a lower species diversity. The decreased complexity of the Skagerrak food webs indicates vulnerability to further perturbations and pressures should be limited as much as possible to ensure continued ecosystem functions.

Sex Differences in the Effect of Vitamin D on Fatigue in Palliative Cancer Care-A Post Hoc Analysis of the Randomized, Controlled Trial 'Palliative-D'.

In the randomized, placebo-controlled, double-blind trial 'Palliative-D', vitamin D treatment of 4000 IE/day for 12 weeks reduced opioid use and fatigue in vitamin-D-deficient cancer patients. In screening data from this trial, lower levels of vitamin D were associated with more fatigue in men but not in women. The aim of the present study was to investigate possible sex differences in the effect of vitamin D in patients with advanced cancer, with a specific focus on fatigue. A post hoc analysis of sex differences in patients completing the Palliative-D study (n = 150) was performed. Fatigue assessed with the Edmonton Symptom Assessment Scale (ESAS) was reduced in vitamin-D-treated men; -1.50 ESAS points (95%CI -2.57 to -0.43; p = 0.007) but not in women; -0.75 (95%CI -1.85 to 0.36; p = 0.18). Fatigue measured with EORTC QLQ-C15-PAL had a borderline significant effect in men (-0.33 (95%CI -0.67 to 0.03; p = 0.05)) but not in women (p = 0.55). The effect on fatigue measured with ESAS in men remained the same after adjustment for opioid doses (p = 0.01). In conclusion, the positive effect of the correction of vitamin D deficiency on fatigue may be more pronounced in men than in women. However, studies focused on analyzing sex differences in this context must be performed before firm conclusions can be drawn.

Food web assessments in the Baltic Sea: Models bridging the gap between indicators and policy needs.

Ecosystem-based management requires understanding of food webs. Consequently, assessment of food web status is mandatory according to the European Union's Marine Strategy Framework Directive (MSFD) for EU Member States. However, how to best monitor and assess food webs in practise has proven a challenging question. Here, we review and assess the current status of food web indicators and food web models, and discuss whether the models can help addressing current shortcomings of indicator-based food web assessments, using the Baltic Sea as an example region. We show that although the MSFD food web assessment was designed to use food web indicators alone, they are currently poorly fit for the purpose, because they lack interconnectivity of trophic guilds. We then argue that the multiple food web models published for this region have a high potential to provide additional coherence to the definition of good environmental status, the evaluation of uncertainties, and estimates for unsampled indicator values, but we also identify current limitations that stand in the way of more formal implementation of this approach. We close with a discussion of which current models have the best capacity for this purpose in the Baltic Sea, and of the way forward towards the combination of measurable indicators and modelling approaches in food web assessments.

'Palliative-D'-Vitamin D Supplementation to Palliative Cancer Patients: A Double Blind, Randomized Placebo-Controlled Multicenter Trial.

The aim of the 'Palliative-D' study was to test the hypothesis that correction of vitamin D deficiency reduces opioid use in cancer patients admitted to palliative care. A multicenter randomized, placebo-controlled, double-blind trial in three home-based palliative care facilities in Sweden was performed. Patients with advanced cancer and 25-hydroxyvitamin D < 50 nmol/L were randomized to vitamin D3 4000 IU/day or placebo for 12 weeks. The primary endpoint was the difference of long-acting opioid use (fentanyl ug/h) between the groups during 12 weeks, based on four time points. Secondary outcomes included changes in antibiotic use, fatigue and Quality of Life (QoL). A total of 244 patients were randomized, and 150 patients completed the 12 weeks. The major reason for drop-out was death due to cancer. The vitamin D-group had a significantly smaller increase of opioid doses compared to the placebo-group; beta coefficient -0.56 (p = 0.03), i.e., 0.56 µg less fentanyl/h per week with vitamin D treatment. Vitamin D-reduced fatigue assessed with ESAS was -1.1 points after 12 weeks (p < 0.01). Antibiotic use or QoL did not differ significantly between the groups. The treatment was safe and well-tolerated. In conclusion, correction of vitamin D deficiency may have positive effects on opioid use and fatigue in palliative cancer patients, but only in those with a survival time more than 12 weeks.

Disentangling temporal food web dynamics facilitates understanding of ecosystem functioning.

Studying how food web structure and function vary through time represents an opportunity to better comprehend and anticipate ecosystem changes. Yet, temporal studies of highly resolved food web structure are scarce. With few exceptions, most temporal food web studies are either too simplified, preventing a detailed assessment of structural properties or binary, missing the temporal dynamics of energy fluxes among species. Using long-term, multi-trophic biomass data coupled with highly resolved information on species feeding relationships, we analysed food web dynamics in the Gulf of Riga (Baltic Sea) over more than three decades (1981-2014). We combined unweighted (topology-based) and weighted (biomass- and flux-based) food web approaches, first, to unravel how distinct descriptors can highlight differences (or similarities) in food web dynamics through time, and second, to compare temporal dynamics of food web structure and function. We find that food web descriptors vary substantially and distinctively through time, likely reflecting different underlying ecosystem processes. While node- and link-weighted metrics reflect changes related to alterations in species dominance and fluxes, unweighted metrics are more sensitive to changes in species and link richness. Comparing unweighted, topology-based metrics and flux-based functions further indicates that temporal changes in functions cannot be predicted using unweighted food web structure. Rather, information on species population dynamics and weighted, flux-based networks should be included to better comprehend temporal food web dynamics. By integrating unweighted, node- and link-weighted metrics, we here demonstrate how different approaches can be used to compare food web structure and function, and identify complementary patterns of change in temporal food web dynamics, which enables a more complete understanding of the ecological processes at play in ecosystems undergoing change.

Vitamin D and Fatigue in Palliative Cancer: A Cross-Sectional Study of Sex Difference in Baseline Data from the Palliative D Cohort.

Background: Fatigue is one of the most distressing symptoms in patients with advanced cancer. Previous studies have shown an association between low vitamin D levels and fatigue. Objectives: The aim of this study was to investigate the association between vitamin D levels and self-assessed fatigue in cancer patients admitted to palliative care, with focus on possible sex differences. Design: This is a cross-sectional study. Subjects: Baseline data from 530 screened patients, 265 women and 265 men, from the randomized placebo-controlled trial "Palliative-D" were analyzed. Measurements: Vitamin D status was measured as 25-hydroxyvitamin D (25-OHD) and fatigue was assessed with EORTC-QLQ-PAL15 and with Edmonton Symptom Assessment System (ESAS). Results: In men, there was a significant correlation between 25-OHD and fatigue measured with the "Tiredness question" (Q11) in EORTC-QLQ-PAL15 (p < 0.05), where higher 25-OHD levels were associated with less fatigue. No correlation between 25-OHD and fatigue was seen for women. Fatigue measured with ESAS did not show any significant association with 25-OHD levels neither in men nor in women. Conclusion: Low vitamin D levels were associated with more fatigue in men but not in women. The study underscores the importance of subgroup analysis of men and women when evaluating the effect of vitamin D in clinical trials since the effect may differ between the sexes. The ongoing "Palliative-D study" will reveal whether vitamin D supplementation may counteract fatigue in both men and women. ClinicalTrial.gov: NCT03038516.

Central nervous system lymphoma and radiofrequency radiation - A case report and incidence data in the Swedish Cancer Register on non-Hodgkin lymphoma.

Earlier animal studies have provided evidence that non-Hodgkin lymphoma (NHL) may be caused by exposure to radiofrequency (RF) radiation. This was recently confirmed by the U.S. National Toxicology (NTP) study that showed an increased incidence of malignant lymphoma in female mice exposed to the GSM modulated or the CDMA modulated cell phone RF radiation. Primary central nervous system lymphoma (PCNSL) is a rare malignancy in humans with poor prognosis. An increasing incidence has been reported in recent years. Based on a case-report we present the hypothesis that use of the hand-held mobile phone may be a risk factor for PCNSL. The increasing incidence of non-Hodgkin lymphoma in Sweden is discussed in relation to etiologic factors.

Predation risk and competition affect habitat use of adult perch, Perca fluviatilis.

The aim of this study was to examine how the presence of a predator and an interspecific competitor influence the habitat use of adult perch (Perca fluviatilis; size: 15.1 ± 0.5 cm) when given the choice between two adjacent habitats. By conducting aquarium experiments, the habitat occupancy of P. fluviatilis was documented in the presence and absence of a predator (pike Esox lucius; size: 25.4 ± 2.1 cm) and a potential competitor (ruffe Gymnocephalus cernuus; size: 14.1 ± 0.3 cm) fish species. Two P. fluviatilis individuals generally shared the same habitat. In the presence of a conspecific, P. fluviatilis favoured the structurally more-complex, artificial macrophyte habitat over the less-structured rock and sand habitat, which in turn were used equally. In the predator- and competitor treatments, P. fluviatilis seemed to adapt their habitat use to the habitat occupancy of E. lucius and G. cernuus in the Macrophyte vs. Rock and, in the predator treatment, also in the Macrophyte vs. Sand habitat combination, by increasingly occupying a habitat that was used less by the predator or competitor species, respectively. This behaviour suggests that P. fluviatilis tried to avoid the other fish species by choosing a, in some cases less preferred, predator- or competitor-free habitat. This study emphasizes the importance of biological interactions illustrated by the potential of predation risk and competition to structure fish communities by influencing habitat use at small spatial scales.

Contribution of deltaic wetland food sources to coastal macrobenthic consumers (Po River Delta, north Adriatic Sea).

Estuaries are known to export huge quantities of terrigenous/riverine organic matter and nutrients to coastal areas, subsidizing food sources to their communities; however, this process is seldom investigated in complex multichannel delta-prodelta systems. Stable isotope analysis was used to investigate the contribution of organic sources originated from the Po River Delta, one of the widest deltaic wetlands in the northern Mediterranean Sea, to the diet of the nearby coastal macrobenthic consumers, and their influence on invertebrates' trophic structure and biomass. Following intense river flood events, macrofauna samples were collected in the prodelta area at increasing distance from the main river distributary mouth. Potential primary resources were collected within the delta and the prodelta areas. A terrestrial signal in the primary consumers' diet was evident as a shift in their δ13C, being this more 13C depleted near the main river distributary. The Bayesian mixing models indicated an important contribution of deltaic sources, in particular C4-grass detritus (25-57%), to primary consumers' diet, confirming a strong energetic link between delta and prodelta areas. Overall, most of the consumers' biomass were concentrated at sites close to the main distributary mouth, mainly as suspension and surface deposit feeders. A simplification of the macrobenthic community structure, accompanied by narrower transfer pathways was also evident at sites more distant from the main river distributary, in relation to changes in the quality of resources. Our data, although limited to winter season, suggest that during periods of low in situ productivity but high river flow energy, invertebrates are able to efficiently exploit terrigenous food sources, restraining the detrimental effect of increased turbidity and sedimentation. We conclude that riparian/wetland vegetation associated with river deltas can provide important food sources to marine primary consumers. These results furthermore highlight the need for integrated management and protection strategies of connected land-sea ecosystems.

High Degree of Satisfaction With the Support Given by Multidisciplinary Palliative Home Care Teams in the County of Stockholm.

OBJECTIVE: At the initiative of Stockholm County Council, a survey was performed by an independent investigator to evaluate satisfaction among patients and their families with the advanced palliative home care teams in the county of Stockholm. The survey was performed in 2010 and compiled in 2011. The aim was to evaluate the impressions of patients and their families of the support given by the palliative home care teams in the Stockholm area and to evaluate the management of symptom control, availability, continuity, confidence, and quality of communication. METHODS: A questionnaire was sent to 1424 patients and 329 family members to evaluate the views of the users of the home care service. RESULTS: The response rate was 78% among both patients and their families or other caregivers. The proportion of positive and very positive responses among those who needed the specific help of the team was as follows: information about the service 86%, availability around the clock 96%, influence and feeling of shared responsibility 88%, and possibility of family members to have supportive discussions 95%. Eighty-three percent of patients experienced total pain relief and 99% total or partial relief. The corresponding figures for anxiety were 77% and 97% and for other symptom reliefs 79% and 98%, respectively. These figures were comparable to a smaller survey in 2014 and were high compared to the results from other medical services using similar questionnaires. Significance of the Results: A high quality of care is possible to achieve within palliative home care services.

Vitamin D supplementation to palliative cancer patients: protocol of a double-blind, randomised controlled trial 'Palliative-D'.

BACKGROUND: According to a small pilot study on palliative cancer patients at our ward, vitamin D supplementation had beneficial effects on pain (measured as opioid consumption), infections and quality of life (QoL) without having any significant side effects. OBJECTIVE: The primary objective of the 'Palliative-D' study is to test the hypothesis that vitamin D supplementation for 12 weeks reduces opioid consumption. The secondary objectives are to study if reduction of antibiotic consumption and fatigue as well as improvement in QoL assessments can be observed. Effect on the 25-hydroxy vitamin D (25-OHD) levels in serum after 12 weeks of treatment will be studied, as well as the change in opioid dose in relation to genetic polymorphism in genes involved in the effect and metabolism of vitamin D. METHOD: A randomised, double-blind placebo-controlled multicentre trial has been designed. The trial will include 254 adult palliative cancer patients with 25-OHD levels <50 nmol/L and a life expectancy of more than 3 months recruited from two advanced palliative home care centres in Stockholm. Included patients will be randomly assigned to 12 weeks of treatment with cholecalciferol (vitamin D3) 4000 IU/day or placebo. The study will start in November 2017 and will finish in December 2019. The study is approved by the Regional Ethical Committee, Dnr2017/405-31/1, by the Swedish Medical Products Agency, EudraCT: 2017-000268-14, and is registered at Clinicaltrial.gov: NCT03038516. The study is financed with research grants from the Swedish Cancer Society and the Stockholm County Council.

The importance of benthic-pelagic coupling for marine ecosystem functioning in a changing world.

Benthic-pelagic coupling is manifested as the exchange of energy, mass, or nutrients between benthic and pelagic habitats. It plays a prominent role in aquatic ecosystems, and it is crucial to functions from nutrient cycling to energy transfer in food webs. Coastal and estuarine ecosystem structure and function are strongly affected by anthropogenic pressures; however, there are large gaps in our understanding of the responses of inorganic nutrient and organic matter fluxes between benthic habitats and the water column. We illustrate the varied nature of physical and biological benthic-pelagic coupling processes and their potential sensitivity to three anthropogenic pressures - climate change, nutrient loading, and fishing - using the Baltic Sea as a case study and summarize current knowledge on the exchange of inorganic nutrients and organic material between habitats. Traditionally measured benthic-pelagic coupling processes (e.g., nutrient exchange and sedimentation of organic material) are to some extent quantifiable, but the magnitude and variability of biological processes are rarely assessed, preventing quantitative comparisons. Changing oxygen conditions will continue to have widespread effects on the processes that govern inorganic and organic matter exchange among habitats while climate change and nutrient load reductions may have large effects on organic matter sedimentation. Many biological processes (predation, bioturbation) are expected to be sensitive to anthropogenic drivers, but the outcomes for ecosystem function are largely unknown. We emphasize how improved empirical and experimental understanding of benthic-pelagic coupling processes and their variability are necessary to inform models that can quantify the feedbacks among processes and ecosystem responses to a changing world.

Predicting the consequences of species loss using size-structured biodiversity approaches.

Understanding the consequences of species loss in complex ecological communities is one of the great challenges in current biodiversity research. For a long time, this topic has been addressed by traditional biodiversity experiments. Most of these approaches treat species as trait-free, taxonomic units characterizing communities only by species number without accounting for species traits. However, extinctions do not occur at random as there is a clear correlation between extinction risk and species traits. In this review, we assume that large species will be most threatened by extinction and use novel allometric and size-spectrum concepts that include body mass as a primary species trait at the levels of populations and individuals, respectively, to re-assess three classic debates on the relationships between biodiversity and (i) food-web structural complexity, (ii) community dynamic stability, and (iii) ecosystem functioning. Contrasting current expectations, size-structured approaches suggest that the loss of large species, that typically exploit most resource species, may lead to future food webs that are less interwoven and more structured by chains of interactions and compartments. The disruption of natural body-mass distributions maintaining food-web stability may trigger avalanches of secondary extinctions and strong trophic cascades with expected knock-on effects on the functionality of the ecosystems. Therefore, we argue that it is crucial to take into account body size as a species trait when analysing the consequences of biodiversity loss for natural ecosystems. Applying size-structured approaches provides an integrative ecological concept that enables a better understanding of each species' unique role across communities and the causes and consequences of biodiversity loss.

Regime shifts in marine communities: a complex systems perspective on food web dynamics.

Species composition and habitats are changing at unprecedented rates in the world's oceans, potentially causing entire food webs to shift to structurally and functionally different regimes. Despite the severity of these regime shifts, elucidating the precise nature of their underlying processes has remained difficult. We address this challenge with a new analytic approach to detect and assess the relative strength of different driving processes in food webs. Our study draws on complexity theory, and integrates the network-centric exponential random graph modelling (ERGM) framework developed within the social sciences with community ecology. In contrast to previous research, this approach makes clear assumptions of direction of causality and accommodates a dynamic perspective on the emergence of food webs. We apply our approach to analysing food webs of the Baltic Sea before and after a previously reported regime shift. Our results show that the dominant food web processes have remained largely the same, although we detect changes in their magnitudes. The results indicate that the reported regime shift may not be a system-wide shift, but instead involve a limited number of species. Our study emphasizes the importance of community-wide analysis on marine regime shifts and introduces a novel approach to examine food webs.

Novel biodiversity baselines outpace models of fish distribution in Arctic waters.

During a recent marine biological expedition to the Northeast Greenland shelf break (latitudes 74-77 °N), we made the first discovery of Atlantic cod (Gadus morhua), beaked redfish (Sebastes mentella) and capelin (Mallotus villosus). Our novel observations shift the distribution range of Atlantic cod >1000 km further north in East Greenland waters. In light of climate change, we discuss physical forcing and putative connections between the faunas of the Northeast Greenland shelf and the Barents Sea. We emphasise the importance of using real data in spread scenarios for understudied Arctic seas.

Successful change of treatment strategy in elderly patients with primary central nervous system lymphoma by de-escalating induction and introducing temozolomide maintenance: results from a phase II study by the Nordic Lymphoma Group.

The Nordic Lymphoma Group has conducted a phase ll trial in newly diagnosed primary central nervous system lymphoma patients applying an age-adjusted multi-agent immunochemotherapy regimen, which in elderly patients included temozolomide maintenance treatment. Patients aged 18-75 years were eligible. Thirty-nine patients aged 18-65 years and 27 patients aged 66-75 years were enrolled. The median age of the two age groups was 55 and 70 years, respectively. The overall response rate was 73.8% for the entire cohort: 69.9% in the younger and 80.8% in the elderly subgroup. With a median follow up of 22 months, the 2-year overall survival probability was 60.7% in patients aged 65 years or under and 55.6% in patients aged over 65 years (P=0.40). The estimated progression-free survival at two years was 33.1% (95%CI: 19.1%-47.9%) in patients aged under 65 years and 44.4% (95%CI: 25.6%-61.8%) in the elderly subgroup (P=0.74). Median duration of response was ten months in the younger subgroup, and not reached in the elderly patient subgroup (P=0.33). Four patients aged 64-75 years (6%) died from treatment-related complications. Survival in the two age groups was similar despite a de-escalation of induction treatment in patients aged over 65 years. Duration of response in elderly patients receiving maintenance temozolomide was longer than in the younger age subgroup. While toxicity during induction is still of concern, especially in the elderly patients, we conclude from these data that de-escalation of induction therapy in elderly primary central nervous system lymphoma patients followed by maintenance treatment seems to be a promising treatment strategy. (clinicaltrials.gov identifier:01458730).