The sodium pump (SP or Na+,K+-ATPase) is a membrane embedded protein complex that pumps 3 sodium ions out and 2 potassium ions into the cell per cycle and in so doing creates a cell membrane electrochemical potential. The membrane potential is critical for any functional cell. In the vasculature, reduction in the voltage potential causes vascular smooth muscle contraction and a narrowing of blood vessels (vasoconstriction) which can lead to increased blood pressure (hypertension). Substantial research over the past several decades has provided a vast amount of research on SP inhibitors, sometimes called endogenous digitalis-like factors (EDLF). Increased levels of these factors have been implicated in many hypertensive disorders including preeclampsia (PE), a life-threatening complication of pregnancy. It has been demonstrated that EDLF might be a causative factor in the pathophysiology of hypertension in PE. In order to elucidate EDLF production and regulation in PE, We developed a radioimmunoassay (RIA) measuring EDLF that could be applied to serum from pregnant women, placental homogenate and placental tissue culture. This assay employs Digibind, a commercially available Fab fragment derived from polyclonal antidigoxin antibodies that cross reacts with EDLF, as the primary antibody. Using Digibind RIA, we demonstrated that placenta is a source of EDLF production and regulation. Moreover, the identification of an inhibitor, ketoconazole and a substrate, 17-hydroxyprogesterone of the synthetic pathway of EDLF in placenta proved that this pathway shares steps with the steroid synthetic pathway. Some potential regulatory agents which have elevated levels in PE or be associated in PE and thus are thought to mediate PE, such as hydrogen peroxide, tumor necrosis factor-α (TNF-α) and hypoxia have also been demonstrated to be stimuli of EDLF production in placenta. These findings are helpful to the further study on EDLF synthesis and regulation in placenta. Once we elucidate the mechanisms, it could be easier to provide deeper insights into the pathogenesis of PE and subsequently develop earlier diagnosis and effective prevention of or therapeutic approaches to PE.

Digitalis in one of the most frequently prescribed drugs, especially to elderly people. The prescription of cardiac glucosides (1978) was studied by using statistics from Apoteksbolaget (the National Corpora­tion of Swedish Pharmacies). There was a threefold difference in the sales of cardiac glucosides per 1000 inhabitants in the different primary care areas. Digoxin was prescribed to 90-98 per cent of the patients, with considerable variations in the dosages. Many other factors besides the cardio-vascular morbidity were likely to cause these differences. Maintenance digitalis therapy has lately been questioned. In a retro­spective study, digitalis was discontinued in 141 geriatric patients without contraindications to digitalis withdrawal. Digoxin treatment seemed to be unnecessary in 108 patients (81 per cent), followed up two months after digoxin withdrawal. A long-term study (mean: 20,5 months) was carried out in these 108 patients. Digitalis therapy was reinstituted in 30 of 99 patients, equally distributed on the basis of clear, possible or uncertain indications. Significantly more patients (p&lt; 0,001) with atrial fibrillation compared with sinus rhythm were restarted. A prospective, randomized, double-blind placebo- controlled study in 39 out of 66 geriatric patients confirmed the results of the retrospective study. During a two-month period 32 of 37 patients (86 per cent) managed without digitalis. Eighteen out of 66 patients (27 per cent) presented contraindications to digoxin with­drawal. Those who needed digitalis were restarted mainly during the first nonth (mean: 18 days) following digoxin withdrawal. Digitalis intoxication has been studied earlier, mainly in hospitalized patients. A clinical examination and ECG of a random sample of out­patients treated with digoxin shewed that about 5 per cent were certainly intoxicated and about 2 per cent suspected of being intoxi­cated. Elderly patients are said to be more sensitive to digitalis. Eleven per cent of 66 geriatric patients were found, without doubt, to be digitalis intoxicated. The mean serum digoxin concentration was significantly higher in eight toxic patients compared with non-toxic patients, but 75 per cent of the toxic patients had serum digoxin con­centrations within or below therapeutic range. Five of these intoxi­cated patients did not need maintenance digitalis therapy. A questionnaire of 361 patients in Skellefteå and Uppsala revealed that about 45 per cent had taken digitalis for more than five years. Approximately 85 per cent took one tablet daily and stated compliance. About one fifth did not know why they were taking digoxin and about half of the patients were uncertain if they were improved, by digitalis therapy. Although digitalis intoxication is such an important clinical problem, some 55 per cent did not know about digitalis's side-effects and some 50 per cent stated that no or insufficient information had been given. Only 15 per cent were satisfied with the information they had received. A significant negative correlation between digoxin dosages and the age of the patients was found. / <p>Diss. Umeå : Umeå universitet, 1983, härtill 7 uppsatser</p> / digitalisering@umu

Die Dermatitis digitalis (DD) ist eine weltweit verbreitete infektiöse Klauenerkrankung mit negativem Einfluss auf das Wohlbefinden und die Leistung von Milchrindern. Durch die multifaktoriell bedingte Ätiologie und die unterschiedlichen klinischen Erscheinungsformen gestaltet sich die Therapie und Prophylaxe der Erkrankung als schwierig. Schätzungen für Erblichkeiten im moderaten Bereich und die Identifizierung von verschiedenen Kuhtypen hinsichtlich der Anfälligkeit für DD unterstreichen die mögliche Beteiligung von wirtseigenen genetischen Faktoren an der Entstehung der Erkrankung. Unter Anwendung einer intensiven Phänotypisierung DD-betroffener Tiere wurden im Rahmen dieser Arbeit genetisch bedingte Hintergründe der Erkrankung untersucht, Erblichkeiten berechnet und eine Zuchtwertschätzung für DD entwickelt. Zudem war beabsichtigt über eine genomweite Assoziationsstudie (GWAS) relevante chromosomale Bereiche, Kandidatengene und funktionelle Gengruppen für Merkmale, die die Anfälligkeit und den Verlauf der Erkrankung beschreiben, zu identifizieren. Die Ergebnisse der vorliegenden Arbeit liefern neue Erkenntnisse hinsichtlich einer züchterischen sowie genomischen Bearbeitung der DD des Holstein-Rindes. Dabei stellt die Nutzung von Phänotypen aus der wiederholten Einstufung von Kühen mittels M-Stadien-Klassifizierungssystem eine Innovation gegenüber der bisherigen Zuchtwertschätzung für Klauenerkrankungen dar. Insgesamt bestätigen die Ergebnisse eine bereits angenommene polygenetische Beeinflussung der DD beim Holstein-Rind. Eine gezielte züchterische Bearbeitung sollte flächendeckend und ergänzend zu allgemeinen Präventions- und therapeutischen Maßnahmen eingesetzt werden.

Preeclampsia (PE) is a multisystem disorder that contributes to maternal and fetal mortality and morbidity worldwide. It is characterized by de-novo hypertension and proteinuria or other maternal organ damage after 20 weeks of gestation. Evidence suggested that endogenous digitalis-like factor (EDLF) contributes to the pathogenesis of PE, and that the potential source of EDLF is the placenta. EDLF can inhibit the sodium pump (SP) specifically and may lead to hypertension, it has also been associated with hypoxia, oxidative stress and other abnormalitites present in PE.We studied whether normal human placenta responded to SP inhibition casued by EDLF with a change in abundance of lipids in the placental cytosol, and whether there was a characteristic set of lipid changes that could serve as a signature for EDLF exposure if there were such changes. Placenta tissues from 20 normal pregnancies were incubated for 48 hr in the presence and absence of ouabain, a widely studied EDLF, followed by tissue homogenization, lipid extraction, and the study of lipids using a mass spectrometery (MS) based lipidomics approach. 1207 lipidomic markers were surveyed by paired Student t-test, among which 26 markers had significantly different abundances between cases and control at the FDR=0.05 level. A set of 8 lipidomic markers were selected by a statistical model built with a sparse partial least squares discriminant analysis method (sPLS-DA) and a bootstrap procedure. All eight markers were then chemically characterized and partially identified using tandem MS. These markers might be used to identify placentas that have been previously exposed to EDLF in return.Endogenous peptides and small proteins might contribute to the pathophysiology of various diseases. Therefore, we investigated the potential peptidomic profile of placenta tissues in response to EDLF exposure as well. Placenta tissues from 20 normal pregnancies were incubated for 25 hr with and without the addition of ouabain, followed by homogenization, protein depletion, and the study of the peptides by a LC-MS based peptidomics approach. 275 peptidomic markers were evaluated by Student t-test. A set of 8 markers was chosen using a logistic regression model build with the Akaike information criterion (AIC). However, no peptidomics markers or set of markers showed specific, statististically significantly different changes in abundances between cases and controls after applying a false discovery rate (FDR) correction or using more conservative methods to overcome over-fitting. Using an optimal sPLS- DA, cross-validation studies and logistic regression models, we also found that the addition of any peptidomic marker to the previously selected lipidomic profile was unlikely to help identify placentas that had been exposed to EDLF.Alzheimer's disease (AD) is the most common form of dementia and the number of AD cases worldwide is currently estimated to be 36 million. The exact pathogenesis of AD remainsiielusive and available therapeutic strategies can only delay its progession temporarily. Several hypotheses have been proposed regarding the pathophysiology of AD and the beta-amyloid (Aβ) hypothesis is considered the core mechanism. However, the majority of studies concerning AD, or AD biomarkers specifically, have ignored a potentially important variable that is gender, despite reported gender differences in the risk of developing AD, the risk factors, clinical symptoms and CSF biomarkers of the disease, among many other aspects.We analyzed data obtained from a previous study of diagnostic serum lipid biomarkers for AD with the consideration of potential gender difference. Firstly, we studied the interaction between gender and disease stage using analysis of variance (ANOVA) and analysis of covariance (ANCOVA). Lipid markers that showed statistically significant interaction were selected after applying a FDR correction. Secondly, using a lasso logistic regression model with binary classification (control vs. all AD stages), we identified gender-specific markers and found different coefficient estimates for different genders as well. Lastly, we build a new ordinal model with the addition of a gender-specific marker using a Bayesian lasso probit ordinal regression model. The predictive performance of the new model was found to be statistically significantly better than the previous model which was built without the consideration of gender.In conclusion, we successfully discovered, chemically characterized lipidomic markers indicative of EDLF exposure in placenta and detected gender-specific lipid markers for AD.

No description available.

Amb l'objectiu d'analitzar com la biodiversitat i l'adaptació al clima mediterrani es tradueixen en una diversitat de trets ecofisiològics i la seva resposta a la sequera, i d'estudiar si aquesta diversitat està relacionada amb formes de creixement i amb la història evolutiva de les espècies, es van seleccionar 24 espècies mediterrànies de les Illes Balears. Es va analitzar la capacitat germinativa, els efectes de la sequera en el creixement de plàntules, respostes ecofisiològiques a la sequera a nivell foliar i l'adaptació de l'especificitat de la Rubisco. Es va observar una elevada variabilitat entre espècies, la meitat de la qual associada a les diferents formes de creixement. No s'observà cap diferenciació entre les espècies endèmiques i les no endèmiques. Aquesta elevada diversitat en els trets ecofisiològics i la seva resposta a la sequera suposa un recurs potencial per identificar caràcters adaptatius i un banc genètic per millorar la productivitat de cultius. / Con el objetivo de analizar como la biodiversidad y la adaptación al clima mediterráneo se traducen en una diversidad de caracteres ecofisiológicos y su respuesta a la sequía, y de estudiar si esta diversidad está relacionada con formas de crecimiento y con la historia evolutiva de las especies, se seleccionaron 24 especies mediterráneas de las Islas Baleares. Se analizaron la capacidad germinativa, los efectos de la sequía sobre el crecimiento de las plántulas, las respuestas ecofisiológicas a la sequía a nivel foliar y la adaptación de la especificidad de la Rubisco. Se observó una elevada variabilidad entre especies, la mitad de la cual asociada a las diferentes formas de crecimiento. No se encontraron diferencias entre las especies endémicas y las no endémicas. Esta elevada biodiversidad en respuesta a la sequía supone un recurso potencial para identificar caracteres adaptativos y un banco genético para la mejora de la productividad de cultivos. / The objectives of this work were to analyze how biodiversity and adaptation to Mediterranean climate is reflected in a diversity of ecophysiological traits and their responses to drought, and to study whether such diversity was related to growth forms and endemicity. The analysis covered the germination capacity, the effects of drought on seedling growth, the leaf ecophysiological responses to drought, and the adaptation of Rubisco specificity, in 24 Mediterranean species from the Balearic Islands. A wide range of variation has been observed among the species, with about half of this variability associated to different growth forms. However, no differentiation was found between endemic and non-endemic species of the Balearic Islands. The high diversity in the ecophysiological traits and their responses to drought found among Mediterranean species must be considered as a 'resource' to identify target adaptive traits for breeding plans, but also as a genetic bank to improve crop productivity.

Bovine Dermatitis digitalis (DD) ist eine weltweit verbreitete Infektionskrankheit bei Rindern, die primär die plantare Haut über dem Kronenrand nahe des Zwischenzehenspalts der Hinterklauen betrifft. Schmerzhafte ulzero-proliferative Läsionen mit akuten und chronischen Erscheinungsformen führen zu Verhaltensänderungen und Lahmheit der Tiere. DD hat damit einen erheblichen Einfluss auf deren Wohl und ihre Leistungen. Zahlreiche Untersuchungen zur Ätiologie der Krankheit ergaben, dass es sich um das Zusammenspiel verschiedener Ursachen handelt. Einer synergistischen multifaktoriellen Infektion mit starker Beteiligung von Bakterien der Gattung Treponema kommt dabei besondere Bedeutung zu. Aspekte wie Tierhaltung, Hygienestandards und genetische Prädispositionen wurden ebenfalls intensiv untersucht. Nichtsdestotrotz bleiben Infektionsherde, Transmissionsrouten und Pathomechanismen weitgehend unklar. Zum besseren Verständnis der Ereignisse, die zu DD-Läsionen führen, sollte im Zuge dieser Arbeit ein organotypisches Zellkulturmodell der bovinen Haut erstellt werden, welches in späteren Versuchen mit dem Krankheitserreger zum Einsatz kommen soll. Verlässliche und reproduzierbare Techniken zur Isolation und Kultur von bovinen primären Keratinozyten und Fibroblasten wurden etabliert; geeignete Zellkulturmedien für die Langzeitkultivierung und –aufbewahrung der Hautzellen wurden identifiziert. Zur Erstellung des Hautmodells wurden zwei verschiedene Ansätze miteinander verglichen. Der zweite Ansatz, bei dem Keratinozyten direkt auf ein dermales Äquivalent, d.h. ein Pad aus bovinem Kollagen I mit eingesäten post-mitotischen Fibroblasten, gesät wurden, brachte ein vielversprechendes Hautmodell hervor. Die inkorporierten post-mitotischen Fibroblasten wiesen eine charakteristische Zellmorphologie mit intakten Nuklei auf. Die terminale Differenzierung der Keratinozyten auf dem dermalen Äquivalent wurde mittels Immunfluoreszenzfärbungen mit Antikörpern gegen die Markerproteine Keratin 14 und Desmoglein 1 gezeigt. Die Ergebnisse erster Experimente mit Treponema spp. verdeutlichen, dass das Hautäquivalent ein geeignetes Modell zur Untersuchung der Pathogenese der DD darstellt. / Bovine digital dermatitis (DD) is a worldwide occurring, infectious disease in cattle primarily affecting the plantar skin above the coronary band near the interdigital cleft on hind feet. Painful ulceroproliferative lesions with acute and chronic appearances lead to behavioral changes and lameness. Hence, DD has a major impact on animal welfare and performance. Substantial efforts in investigating the etiology of the disease revealed a synergistic origin with evidence for a multibacterial infection and the strong involvement of bacteria from the genus Treponema. As the interaction between host, pathogen and environment is not negligible, surrounding circumstances such as housing, general hygiene and genetic predispositions have been investigated intensively. Nevertheless, infection reservoirs, transmission routes and pathomechanisms remain widely unclear. To better understand the cellular and molecular events during Treponema-infection of bovine skin, it was the specific aim of this study to establish an organotypic in vitro skin model, which could be challenged with the causative agent of the disease. A technique to reliably and reproducibly isolate primary keratinocytes and fibroblasts from the site of infection was established. Appropriate cell culture media for the long-term cultivation and storage of bovine skin cells were identified. Two different methods to develop the skin model were compared. The second strategy in which keratinocytes were directly seeded on top of a dermal equivalent, i.e. a bovine collagen type I pad with embedded post-mitotic fibroblasts, gave rise to a promising organotypic skin equivalent. The incorporated post-mitotic fibroblasts showed a characteristic cell morphology with intact nuclei. The terminal differentiation of the keratinocytes on top of the dermal equivalent was shown with anti-K14 and anti-Dsg1 immunofluorescence stainings. The results of initial Treponema-experiments proved that the skin equivalent is a suitable model to investigate the underlying mechanisms during Treponema-infection of bovine skin and hence, the pathogenesis of DD.

<p>This thesis examines the isolation and characterisation (biological and chemical) of polypeptides from plants. A fractionation protocol was developed and applied on 100 plant materials with the aim of isolating highly purified polypeptide fractions from small amounts of plant materials. The polypeptide fractions were analysed and evaluated for peptide content and biological activities. A multitarget functional bioassay was optimised as a method for detecting substances interacting with the inflammatory process of activated neutrophil granulocytes. In this assay, the neutrophil was challenged with an inflammatory mediator, <i>N</i>-formyl methionyl-leucyl-phenylalanine (fMLP), or with platelet activating factor (PAF), to induce exocytotic release of the enzyme elastase, which then was quantified by photometric determination of the product p-nitroanilide (pNA) formed from a chromogenic substrate for elastase. Of the tested extracts, 41% inhibited pNA formation more than 60%, and 3% stimulated formation.</p><p>Phoratoxin B and four new peptides, phoratoxins C-F, were isolated from <i>Phoradendron tomentosum</i>. In addition, the cardiac glycoside digitoxin was isolated from <i>Digitalis purpurea</i>. All these substances expressed cytotoxicity and a neutrophil challenging activity.</p><p>Phoratoxins C-F were similar to earlier described phoratoxins A and B, which belong to the group of thionins. All the peptides were evaluated for cytotoxicity in a human cell line panel. Phoratoxin C was the most potent towards the cell lines (mean IC₅₀: 160 nM), and was therefore investigated further on tumour cells from patients. Correlation analysis of the log IC₅₀ values indicated a mechanism of action different from clinically used archetypal cytotoxic drugs. Phoratoxin C also showed selective toxicity to the solid tumours when compared to the haematological cancer types. The phoratoxin C was 18 times more potent towards the solid tumour samples from breast cancer cells (87 nM) compared to the tested haematological malignancies.</p><p>The structure-activity relationship concerning cytotoxicity was evaluated for digitoxin and related cardiac glycosides. Digitoxin was shown to be potent, with the average IC₅₀ 37 nM being within the therapeutic concentration used for cardiac congestion (13-45 nM). Digitoxin expressed selective toxicity towards solid tumours from patients compared to haematological malignancies.</p>

This thesis examines the isolation and characterisation (biological and chemical) of polypeptides from plants. A fractionation protocol was developed and applied on 100 plant materials with the aim of isolating highly purified polypeptide fractions from small amounts of plant materials. The polypeptide fractions were analysed and evaluated for peptide content and biological activities. A multitarget functional bioassay was optimised as a method for detecting substances interacting with the inflammatory process of activated neutrophil granulocytes. In this assay, the neutrophil was challenged with an inflammatory mediator, N-formyl methionyl-leucyl-phenylalanine (fMLP), or with platelet activating factor (PAF), to induce exocytotic release of the enzyme elastase, which then was quantified by photometric determination of the product p-nitroanilide (pNA) formed from a chromogenic substrate for elastase. Of the tested extracts, 41% inhibited pNA formation more than 60%, and 3% stimulated formation. Phoratoxin B and four new peptides, phoratoxins C-F, were isolated from Phoradendron tomentosum. In addition, the cardiac glycoside digitoxin was isolated from Digitalis purpurea. All these substances expressed cytotoxicity and a neutrophil challenging activity. Phoratoxins C-F were similar to earlier described phoratoxins A and B, which belong to the group of thionins. All the peptides were evaluated for cytotoxicity in a human cell line panel. Phoratoxin C was the most potent towards the cell lines (mean IC50: 160 nM), and was therefore investigated further on tumour cells from patients. Correlation analysis of the log IC50 values indicated a mechanism of action different from clinically used archetypal cytotoxic drugs. Phoratoxin C also showed selective toxicity to the solid tumours when compared to the haematological cancer types. The phoratoxin C was 18 times more potent towards the solid tumour samples from breast cancer cells (87 nM) compared to the tested haematological malignancies. The structure-activity relationship concerning cytotoxicity was evaluated for digitoxin and related cardiac glycosides. Digitoxin was shown to be potent, with the average IC50 37 nM being within the therapeutic concentration used for cardiac congestion (13-45 nM). Digitoxin expressed selective toxicity towards solid tumours from patients compared to haematological malignancies.