Ecophysiological diversity of wild<i> Coffea arabica</i> populations in Ethiopia : Drought adaptation mechanisms

Drought is a wide-spread limiting factor in coffee (Coffea arabica L.) production, but the development of adapted cultivars is hampered by a limited understanding of the physiological resistance mechanism and the extreme narrow genetic base of plant material used in breeding. Therefore, the objective of this study was to evaluate the ecophysiological diversity of coffees wild progenitors and their potential for the improvement of drought resistance at its primary gene pool and center of genetic diversity, in Ethiopia. Complementary field and common-garden studies of populations native to habitats spanning a wide range of climatic conditions were examined by combining seasonal measurements in naturally regenerated stands of wild coffee (in-situ) with an artificial drought stress experiment (ex-situ), where seedlings of these populations were raised under controlled environmental conditions and subjected to different watering and light intensity regimes. Plant ecophysiological behavior was assessed in terms of gas exchange activity, leaf water status determined by water potential and osmotic potential measurements, chlorophyll fluorescence and carbon isotope discrimination. The results of both experiments revealed that the ecophysiology of wild C. arabica populations was strongly influenced by conditions of water deficit, heat and high irradiance, which had combined effects on the plants during drought periods. However, the coffee plants were able to adapt to the natural and experimental drought conditions; thereby their resistance mechanism was mainly based on the capability to avoid tissue desiccation. In particular, physiological responses were attributed to fine control of stomatal conductance reducing water loss, high rates of photosynthesis and improved water-use efficiency. Overnight re-saturation of tissue water status with no active osmotic adjustment ability was another important characteristic in drought adaptation of the plants. In addition, the in-situ ecophysiological behavior of populations from different habitats revealed contrasting strategies in response to drought stress, thereby this habitat-specific variability was also found under common-garden conditions. Thus, the results of this study provide evidence that there is a genetic basis of the marked ecophysiological diversity in wild Coffea arabica and that the contrasting habitat conditions result into different selection pressures for traits related to water-use and promote regional differentiation in adaptation to drought stress. Furthermore, the coffee plants exhibited substantial phenotypic plasticity for all ecophysiological traits in response to varying soil moisture conditions; thereby the magnitude of plasticity differed markedly among the populations. In particular, plants originating from drier, variable climates showed the highest amount of plasticity suggesting fast adaptation to changing environmental conditions. A high correlation of plastic responses in most characters was an indicator for a high degree of phenotypic integration demonstrating the need for integrative approaches for the evaluation of drought adaptation in this species. Overall, the profound amount of ecophysiological diversity in the primary gene pool of C. arabica found in this study emphasizes its importance as a unique and valuable genetic resource. The specific adaptations to drought stress suggest a high potential for breeding of improved cultivars and stresses the need for conservation of the profound ecophysiological diversity. In particular, the findings suggest an approach of in-situ conservation within the evolutionary dynamic ecosystems of the natural habitat of Coffea arabica in order to allow the preservation of genes for stress resistance as they co-evolve with their changing environment.Ökophysiologische Diversität in Wildpopulationen von Coffea arabica in Äthiopien - Mechanismen der Trockenstreßadaption Trockenstress gehört weltweit zu den Umweltfaktoren, die im erheblichen Maße das Ertragspotenzial von Arabica-Kaffee (Coffea arabica L.) beeinträchtigen. Da jedoch die Züchtung stressadaptierter Sorten durch mangelnde Kenntnisse des Resistenzmechanismus sowie der engen genetischen Basis moderner Kulturpflanzen stark limitiert ist, untersucht die vorliegende Arbeit das Ausmaß der ökophysiologischen Vielfalt und Züchtungs-potenzial von Arabica-Kaffee in Äthiopien, seinem Ursprung und genetischem Zentrum. Hierzu wurden vier Fragmente des afromontanen Regenwaldes mit natürlichem Vorkommen von Arabicakaffee entlang eines Klimagradienten ausgewählt und das ökophysiologische Verhalten der Pflanzen während natürlich vorkommender Trockenperioden am natürlichen Standort (in-situ) sowie unter kontrollierten Trockenstressbedingungen (ex-situ) untersucht. Die Charakterisierung des pflanzlichen Wasserhaushaltes erfolgte durch Messungen des Gaswechsels, der Chlorophyll-Fluoreszenz, des Blattwasserstatus sowie der δ13C Analyse. Sowohl unter natürlichen als auch unter experimentellen Trockenstressbedingungen war das ökophysiologische Verhalten der Kaffeepflanzen stark von einer Kombination verschiedener Umweltfaktoren wie Bodenwassergehalt, Temperatur, Lichtintensität und dem atmosphärischen Wasserdampfdruckdefizit beeinflusst. An der Ausprägung der Trockenstressresistenz zeigten sich eine Vielzahl von physiologischen Merkmalen beteiligt, die vornehmlich auf Mechanismen zur Vermeidung der Austrocknung des Pflanzengewebes beruhten, wobei eine mögliche Austrocknungs-toleranz durch osmotische Anpassung nicht nachgewiesen werden konnte. Eine Anpassung an Trockenheit erreichten die Pflanzen maßgeblich durch das Aufrechterhalten einer hohen Nettophotosyntheserate, die effektive stomatäre Kontrolle der Transpirationsverluste sowie eine hohe Wasserausnutzungseffizienz. Weiterhin zeigten die Ergebnisse, dass sich die Kaffeepopulationen hinsichtlich der Anpassung an Trockenstress unterschieden, wobei die Ausprägung unter ex-situ Bedingungen auf eine genetische Fixierung der populationsspezifischen Adapations-mechanismen hinweist. Da sich die Unterschiede darüber hinaus als Anpassung an die jeweiligen Umweltbedingungen am natürlichen Standort interpretieren ließen, kann den spezifischen Habitatbedingungen als Selektionsfaktoren eine bedeutende Rolle hinsichtlich der ökophysiologischen Differenzierung der Populationen beigemessen werden. Weiterhin stellt die Arbeit die phänotypische Plastizität als eine wichtige Anpassungs-strategie in den äthiopischen Kaffeepopulationen an veränderte Umweltbedingungen heraus, hinsichtlich dieser auch Populationsunterschiede nachgewiesen werden konnten. Darüber hinaus verdeutlichten die Ergebnisse die Notwendigkeit einer integrierten Betrachtungsweise der untersuchten ökophysiologischen Merkmale, die in Ihrem Zusammenwirken maßgeblich die erfolgreiche Adaptation an Trockenstress beeinflussen. Die in dieser Studie nachgewiesene einmalige ökophysiologische Vielfalt der äthiopischen Wildkaffeepopulationen belegt ihren potenziellen Nutzen in Züchtungsprogrammen und macht somit die Erarbeitung nachhaltiger Schutzkonzepte für den Erhalt dieser wertvollen pflanzengenetischen Ressourcen notwendig. Hierbei sollten Strategien einer In-situ-Konservierung im Vordergrund stehen, um so den Erhalt und die kontinuierliche Weiterentwicklung der ökophysiologischen Diversität von C. arabica für heutige und auch zukünftige Nutzungsinteressen gewährleisten zu können

In-office thermal systems for the treatment of dry eye disease

Dry eye disease affects millions of people worldwide, causing pain, vision disturbance, and reduced productivity. Meibomian gland dysfunction, a major cause of dry eye, is characterized by chronic glandular inflammation, thickening of the meibum, obstruction of terminal ducts, and glandular atrophy. Treatment of meibomian gland dysfunction can utilize heat and pressure applied to the meibomian glands, increasing meibum expression. With self-treatments, however, not all patients achieve lasting improvement, and compliance is often low. In-office thermal systems offer a second line of treatment and could be a much-needed addition for patients who do not respond to conventional treatment. We critically evaluated the efficacy and safety of LipiFlow, iLux, and TearCare based on existing literature. While the studies found a single in-office thermal treatment to be safe and effective in improving short-term signs and symptoms in patients with dry eye, long-term efficacy needs to be further evaluated. Thus, well-controlled, long-term efficacy studies are warranted to draw clear conclusions. The treatment seemed to provide rapid relief of symptoms that may last up to 1 year, but at a considerably higher cost than the at-home treatments. The choice of treatment depends on cost, compliance with at-home treatment, and personal preference.publishedVersio

Greater adherence to a mediterranean diet is associated with lower C-reactive protein (CRP) levels, but not to lower odds of having dry eye disease

Purpose: To investigate the hypothesis that a Mediterranean diet is associated with a lower risk of having dry eye disease (DED) in the general population. Methods: DED was assessed using the Women's Health Study (WHS) dry eye questionnaire in 58,993 participants from the Dutch Lifelines Cohort with complete available dietary data (20–94 years, 60% female). Level of adherence to a traditional Mediterranean diet was assessed using the modified Mediterranean Diet Score (mMDS). High-sensitivity C-reactive Protein (hsCRP) was included as a marker of whole-body inflammation. Logistic regressions were used to examine the relationship between WHS-defined DED and mMDS, corrected for age, sex, BMI, education, income, and 48 potentially confounding comorbidities. The association between mMDS and hsCRP, and hsCRP and DED, was further explored in separate regressions. Results: Of all participants, 9.1% had DED. In contrast to the hypothesis, higher mMDS levels were associated with greater odds of DED, corrected for demographics, smoking status, BMI, and comorbidities (OR 1.034, 95%CI: 1.015 to 1.055, P = 0.001). Moreover, there was a highly significant relationship between increasing mMDS and lower circulating hsCRP levels; however, there was no significant relationship between hsCRP and DED. Conclusions: Stronger adherence to a Mediterranean diet does not appear to be associated with lower odds of having DED in the general population. Furthermore, there was no association between hsCRP and DED in this study. However, the previously described link between a Mediterranean diet and lower hsCRP was confirmed in this large population-based study.</p

Hot towels:The bedrock of Meibomian gland dysfunction treatment – A review

publishedVersionPaid open acces

Greater adherence to a mediterranean diet is associated with lower C-reactive protein (CRP) levels, but not to lower odds of having dry eye disease

Purpose: To investigate the hypothesis that a Mediterranean diet is associated with a lower risk of having dry eye disease (DED) in the general population. Methods: DED was assessed using the Women's Health Study (WHS) dry eye questionnaire in 58,993 participants from the Dutch Lifelines Cohort with complete available dietary data (20–94 years, 60% female). Level of adherence to a traditional Mediterranean diet was assessed using the modified Mediterranean Diet Score (mMDS). High-sensitivity C-reactive Protein (hsCRP) was included as a marker of whole-body inflammation. Logistic regressions were used to examine the relationship between WHS-defined DED and mMDS, corrected for age, sex, BMI, education, income, and 48 potentially confounding comorbidities. The association between mMDS and hsCRP, and hsCRP and DED, was further explored in separate regressions. Results: Of all participants, 9.1% had DED. In contrast to the hypothesis, higher mMDS levels were associated with greater odds of DED, corrected for demographics, smoking status, BMI, and comorbidities (OR 1.034, 95%CI: 1.015 to 1.055, P = 0.001). Moreover, there was a highly significant relationship between increasing mMDS and lower circulating hsCRP levels; however, there was no significant relationship between hsCRP and DED. Conclusions: Stronger adherence to a Mediterranean diet does not appear to be associated with lower odds of having DED in the general population. Furthermore, there was no association between hsCRP and DED in this study. However, the previously described link between a Mediterranean diet and lower hsCRP was confirmed in this large population-based study.</p

Greater adherence to a mediterranean diet is associated with lower C-reactive protein (CRP) levels, but not to lower odds of having dry eye disease

Purpose: To investigate the hypothesis that a Mediterranean diet is associated with a lower risk of having dry eye disease (DED) in the general population. Methods: DED was assessed using the Women's Health Study (WHS) dry eye questionnaire in 58,993 participants from the Dutch Lifelines Cohort with complete available dietary data (20–94 years, 60% female). Level of adherence to a traditional Mediterranean diet was assessed using the modified Mediterranean Diet Score (mMDS). High-sensitivity C-reactive Protein (hsCRP) was included as a marker of whole-body inflammation. Logistic regressions were used to examine the relationship between WHS-defined DED and mMDS, corrected for age, sex, BMI, education, income, and 48 potentially confounding comorbidities. The association between mMDS and hsCRP, and hsCRP and DED, was further explored in separate regressions. Results: Of all participants, 9.1% had DED. In contrast to the hypothesis, higher mMDS levels were associated with greater odds of DED, corrected for demographics, smoking status, BMI, and comorbidities (OR 1.034, 95%CI: 1.015 to 1.055, P = 0.001). Moreover, there was a highly significant relationship between increasing mMDS and lower circulating hsCRP levels; however, there was no significant relationship between hsCRP and DED. Conclusions: Stronger adherence to a Mediterranean diet does not appear to be associated with lower odds of having DED in the general population. Furthermore, there was no association between hsCRP and DED in this study. However, the previously described link between a Mediterranean diet and lower hsCRP was confirmed in this large population-based study.</p

Utfordringer med liberal bruk av D-dimer

Ved akuttmottaket på Sykehuset Østfold Kalnes er D-dimer inkludert i en standard blodprøvepakke hos alle pasienter som rapporterer om brystsmerter eller tungpust. Analysen rekvireres i forkant av en klinisk vurdering. Vår hypotese er at denne praksisen medfører overrekvirering av D-dimer og økt bruk av radiologiske tjenester. De gjeldende nasjonale og internasjonale retningslinjene anbefaler at pasienter med mistenkt lungeemboli utredes med et standardisert scoringsskjema før D-dimer eller CT-undersøkelse rekvireres. Tilgjengelig litteratur viser at liberal bruk av D-dimer, uten å ta hensyn til hvorvidt pasienten kan ha en venøs tromboembolisk tilstand, kan føre til økte kostnader, økt bruk av radiologiske undersøkelser, økt liggetid, og en ineffektiv organisering av tjenesten. Vi foreslår å fjerne D-dimer fra blodprøvepakken og erstatte den med et ekstra citratglass med mulighet for å etterbestille analysen etter det er gjort en klinisk vurdering og bruk av Wells score. Prosessindikatorer som skal benyttes er antall D-dimer analyser, CT-thorax undersøkelser og liggetid i akuttmottaket. Resultatindikatoren skal være antall påviste lungeembolier. Prosjektet skal ledes og gjennomføres av en egnet prosjektgruppe med en tidsplan på seks måneder. Prosjektet skal gjennomføres med utgangspunkt i Modell for kvalitetsforbedring. D-dimeranalyser og CT-undersøkelser skal måles ukentlig og plottes inn i en tidsserie for å kunne observere en eventuell endring. Evalueringsmøter skal holdes månedlig, og det skal ved siste evalueringsmøte vurderes om tiltaket skal implementeres i daglig drift. Vi anbefaler at Sykehuset Østfold Kalnes innfører dagens retningslinjer for bruk av D-dimer og fjerner analysen fra blodprøvepakken. Dette vil trolig være kostnadsbesparende, medføre færre radiologiske tjenester og gi kortere liggetid i mottak uten at det går på bekostning av pasientsikkerheten

Chambered warm moist air eyelid warming devices – a review

Background Eyelid warming is an important treatment for meibomian gland dysfunction (MGD). Specialized chambered devices, using warm moist air have been developed. Purpose To critically evaluate the literature on the safety and efficacy of chambered warm moist air devices in MGD treatment and pinpoint areas of future research. Methods PubMed and Embase were searched on 06 June 2021. The search term was ‘(warm OR heat OR steam OR goggle OR spectacle OR moist air) AND (meibomian OR MGD OR blepharitis OR eyelid OR dry eye OR DED)’. All relevant articles with available English full text were included. Results Eighteen articles assessing the application of chambered warm moist air eyelid warming devices were identified. In single-application studies, steam-based eyelid warming increased the eyelid temperature and improved symptoms, lipid layer thickness, and tear film breakup time (TBUT). In treatment studies, the steam-based devices improved TBUT and symptom scores. However, in the only randomized controlled trial (RCT) comparing chambered steam-based heat to hot towel treatment, there was no difference between groups for the primary outcome measure; the proportion of subjects noting symptom improvement after 4 weeks. Conclusion Currently available chambered warm moist air eyelid warming devices are safe and effective at raising eyelid temperature to therapeutic levels and improving signs and symptoms of dry eye. However, it is not clear if they provide a greater benefit than other eyelid warming therapies. Further well-conducted RCTs comparing moist and dry heat devices should be conducted on patients across the range of DED severities and subtype spectrum.publishedVersio

In-office thermal systems for the treatment of dry eye disease

Dry eye disease affects millions of people worldwide, causing pain, vision disturbance, and reduced productivity. Meibomian gland dysfunction, a major cause of dry eye, is characterized by chronic glandular inflammation, thickening of the meibum, obstruction of terminal ducts, and glandular atrophy. Treatment of meibomian gland dysfunction can utilize heat and pressure applied to the meibomian glands, increasing meibum expression. With self-treatments, however, not all patients achieve lasting improvement, and compliance is often low. In-office thermal systems offer a second line of treatment and could be a much-needed addition for patients who do not respond to conventional treatment. We critically evaluated the efficacy and safety of LipiFlow, iLux, and TearCare based on existing literature. While the studies found a single in-office thermal treatment to be safe and effective in improving short-term signs and symptoms in patients with dry eye, long-term efficacy needs to be further evaluated. Thus, well-controlled, long-term efficacy studies are warranted to draw clear conclusions. The treatment seemed to provide rapid relief of symptoms that may last up to 1 year, but at a considerably higher cost than the at-home treatments. The choice of treatment depends on cost, compliance with at-home treatment, and personal preference