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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

Protein interaction with polyelectrolytes and ligands: A structural and thermodynamic investigation

Yu, Shun 29 August 2017 (has links)
Der erste Teil dieser Arbeit untersucht die Ladungswechselwirkung zwischen Proteinen und Polyelektrolyten. Dabei wird die Bindung von Polyakrylsäure (PAA) als kurzes Modell-Polyelektrolyt an Humanalbumin (HSA) in einer umfassenden experimentellen und theoretischen Studie untersucht und sehr gute Übereinstimmung der Resultate konnte festgestellt werden. Die Computersimulationen in dieser Arbeit wurden von Xiao Xu im Rahmen seiner Promotion durchgeführt. Thermodynamische Daten wurden mit Hilfe von Isothermer Titrationskalorimetrie (ITC) gesammelt und strukturelle Untersuchungen wurden mit Hilfe von Neutronenkleinwinkelstreuung (SANS) durchgeführt. Die Analyse von Bindungsaffinitäten zeigte eine eins zu eins Bindung von PAA mit HSA, die entropisch getrieben ist und strukturellen Untersuchungen weisen eine stabile Proteilstruktur unabhängig von der Adsorption durch PAA auf. Im zweiten Teil der Arbeit wird die Wechselwirkung zweier uremischer Toxinen, nämlich Phenylessigsäure (PhAA) und Indoxylsulfat (IDS), mit HSA untersucht. Eine wichtige Schlussfolgerung aus der Analyse der ITC Daten ist, dass begünstigende, hydrophobe Wechselwirkungen die treibende Kraft für die Adsorption von Toxinen an HSA sind, und dass hierbei die Enthalpie-Entropie-Kompensation (EEC) zu tragen kommt. Weiterhin zeigen SANS Untersuchungen, dass die Proteinstruktur trotz Adsorption stabil bleibt und konnte außerdem über Interpartikulare Wechselwirkung von HSA-Toxin Komplexen aufklären. Im Allgemeinen ist HSA strukturell unverändert durch die Adsorption von Liganden. Diese Feststellung erlaubt die Interpretation von ITC Daten, da damit gemessene Wärmeprozesse ausschließlich von Bindungsprozessen herrühren. Die vorliegende Arbeit konnte zeigen, dass eine ausführliche thermodynamische Analyse durch Kombination von theoretischer mit experimenteller Arbeit, eine umfassende Einsicht in die Mechanismen von Bindungsprozessen ermöglicht. / The first part of the thesis explores the charge-charge interaction between proteins and polyelectrolytes. Polyacrylic acid (PAA) is used as a short model polyelectrolyte to interact with human serum albumin (HSA) the most abundand protein in blood, in a comprehensive experimental and theoretical study. The results thereby coincide very well. Computer simulation studies were performed by Xiao Xu within the framework of his PhD thesis. Thermodynamic data were collected by means of isothermal titration calorimetry (ITC) and structural analysis performed using small-angle neutron scattering (SANS). The analysis of binding free energies revealed one to one binding that is mainly driven by entropy. Structural investigations give proof of the stability of the protein beside adsorption. In the second part, the interaction of two uremic toxins, namely phenylacetic acid (PhAA) and indoxyl sulfate (IDS), with HSA is studied. Systematic ITC experiments reveal two binding sites for both of the two toxins and show small dependence of binding affinities on ionic strength in contrast to PAA adsorption to HSA. This leads to the key conclusion that the favorable hydrophobic interaction is the driving contribution for adsorption and enthalpy-entropy compensation (EEC) effect comes into play. SANS studies of high concentrated HSA-toxin solutions proofed the stability of the protein structure and shed light on the interparticle interaction of HSA-toxin complexes. In general, HSA is structurally robust regardless of ligand uptake. This finding allows the interpretation of ITC data by confirming that the measured heat signals are purely associated to the binding process. The present thesis has demonstrated that a full thermodynamic analysis in combination with theoretical modelling can provide a comprehensive understanding of binding in terms of identifying driving forces and their contributions to protein ligand interaction.
272

Two Clonal Cell Lines of Immortalized Human Corneal Endothelial Cells Show either Differentiated or Precursor Cell Characteristics

Valtink, Monika, Gruschwitz, Rita, Funk, Richard H. W., Engelmann, Katrin January 2008 (has links)
Access to primary human corneal endothelial cells (HCEC) is limited and donor-derived differences between cultures exacerbate the issue of data reproducibility, whereas cell lines can provide sufficient numbers of homogenous cells for multiple experiments. An immortalized HCEC population was adapted to serum-free culture medium and repeated cloning was performed. Clonally grown cells were propagated under serum-free conditions and growth curves were recorded. Cells were characterized immunocytochemically for junctional proteins, collagens, Na,K-ATPase and HCEC-specific 9.3.E-antigen. Ultrastructure was monitored by scanning and transmission electron microscopy. Two clonal cell lines, HCEC-B4G12 and HCEC-H9C1, could be isolated and expanded, which differed morphologically: B4G12 cells were polygonal, strongly adherent and formed a strict monolayer, H9C1 cells were less adherent and formed floating spheres. The generation time of B4G12 cells was 62.26 ± 14.5 h and that of H9C1 cells 44.05 ± 5.05 h. Scanning electron microscopy revealed that B4G12 cells had a smooth cell surface, while H9C1 cells had numerous thin filopodia. Both cell lines expressed ZO-1 and occludin adequately, and little but well detectable amounts of connexin-43. Expression of HCEC-specific 9.3.E-antigen was found commensurately in both cell lines, while expression of Na,K-ATPase α1 was higher in H9C1 cells than in B4G12 cells. B4G12 cells expressed collagen IV abundantly and almost no collagen III, while H9C1 cells expressed both collagens at reasonable amounts. It is concluded that the clonal cell line B4G12 represents an ideal model of differentiated HCEC, while H9C1 may reflect features of developing or transitional HCEC. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
273

Vergleich des Eisenstatus im Serum von gesunden Fohlen und Fohlen mit Bronchopneumonie

Klöpping, Annika 28 May 2024 (has links)
Einleitung: Bei Fohlen ist bisher wenig bekannt über die Eisenparameter im Blut. Das Spurenelement Eisen ist für Säugetiere essenziell, seine Hauptaufgabe ist der Sauerstofftransport. Adulte Pferde nehmen das benötigte Eisen mit dem Raufutter auf, welches in der Regel ausreichend hohe Eisengehalte aufweist. Das Hauptmolekül zur Eisenspeicherung ist Gewebe-Ferritin. Das im Serum vorkommende Serum-Ferritin spiegelt die Gesamteisenmenge des Körpers wider. Im Rahmen einer systemischen Entzündung sinkt der Serum-Eisenspiegel, da Eisen ins Gewebe umverteilt wird und in das Gebiet der Entzündung abwandert. Für die Parameter des Eisenstoffwechsels gibt es keine Referenzwerte für Fohlen, für adulte Pferde gibt es lediglich einen Referenzbereich für Serum-Eisen von 1,00-3,61 mg/l. Es gibt keine Studien, bei denen die Eisenparameter von Fohlen im Alter von ein bis sechs Monaten bestimmt wurden. Ziel der Studie: Ziel der vorliegenden Arbeit war es, die Parameter des Eisenstoffwechsels im Serum bei akuter systemischer Entzündung bei ein bis sechs Monate alten Fohlen zu untersuchen. Außerdem sollte überprüft werden, inwiefern diese Veränderung des Eisenstoffwechsels zu einem Abfall der Serum-Eisenwerte führt. Tiere, Material und Methoden: In dieser prospektiven Studie wurden EDTA-Vollblut- und Serumproben von 66 gesunden Fohlen und 84 Fohlen mit einer akuten systemischen Entzündung in Form einer abszedierenden Bronchopneumonie genommen. Die Fohlen waren im Median 109 Tage alt. Die Diagnose 'Bronchopneumonie' wurde mittels Ultraschalldiagnostik gestellt, die Fohlen hatten am Tag der Probennahme einen sonografisch ermittelten Abszesscore von über 15 cm sowie eine rektal gemessene Körperinnentemperatur über 39,0 °C. Die gesunden Fohlen wiesen eine unauffällige klinische Allgemeinuntersuchung sowie Lungenultraschalluntersuchung am Tag der Probennahme sowie in der vorherigen und darauffolgenden Woche auf. Im Labor wurde der Serum-Amyloid-A-Gehalt bestimmt. Die gesunden Pferde wiesen SAA-Werte innerhalb des Referenzbereiches auf, bei den kranken Pferden bestätigte ein Wert > 7µg/ml die Diagnose einer akuten systemischen Entzündung. Aus der EDTA-Vollblutprobe wurde innerhalb von einer Stunde mittels Durchflusszytometrie die Blutleukozytenzahl bestimmt. Die Analyse der Serumproben erfolgte im Labor LABOKLIN mit dem Analysesystem Cobas 8000 von Roche. Die statistische Auswertung der Daten erfolgte mit dem Statistikprogramm SPSS (IBM Statistics 27). Die Daten der Gesamtpopulation (n = 150) waren nicht normalverteilt. Es wurde ein Mann-Whitney-U-Test als nicht parametrischer Test für zwei unabhängige Stichproben durchgeführt, um signifikante Unterschiede zwischen den Gruppen zu ermitteln. Das Signifikanzniveau wurde auf p < 0,05 festgelegt. Ergebnisse: Bei der Auswertung der Probanden ergab sich für die gesunden Fohlen ein medianer SAA-Wert von 3,50 µg/ml, der der kranken Fohlen liegt mit 541 µg/ml hochsignifikant darüber. Die Bestimmung des Serum-Ferritin-Wertes ergab für die Gruppe der gesunden Fohlen einen Median von 3,80 µg/l (IQR 2,00-4,40 µg/l), der Median für die Gruppe der kranken Fohlen ist mit 4,60 µg/l (IQR 2,48-6,40 µg/l) signifikant (p = 0,003) höher. Die Serum-Eisenwerte der gesunden Fohlen lagen innerhalb des laborinternen Referenzbereichs für adulte Pferde (Median 1,57 mg/l; IQR 1,21-1,79 mg/l), auch die weiteren Bluteisenwerte entsprachen denen adulter Pferde. Die kranken Fohlen zeigten signifikant niedrigere Serum-Eisenwerte (Median 0,550 mg/l; IQR 0,368-0,778 mg/l), signifikant höhere Ferritin- und UIBC-Werte sowie eine signifikant geringere Eisensättigung. Die Auswertung der Leberenzymaktivitäten aus dem Serum ergab für die kranken Fohlen bei allen gemessenen Parametern im Durchschnitt niedrigere Werte als für die gesunden Fohlen. Bei dem Spurenelement Kupfer liegt der Median der gesunden Fohlen mit 18,8 µmol/l (IQR 16,4-20,1 µmol/l) im oberen Bereich der Referenzwerte von 7,9-21 µmol/l, der Median der kranken Fohlen liegt mit 25,7 µmol/l (IQR 23,1-29,0 µmol/l) signifikant über den Werten der gesunden Fohlen (p < 0,001). Schlussfolgerung: Durch eine akute systemische Entzündung kommt es zu einem Abfall des Serum-Eisens durch Umverteilung ins Gewebe und Abwanderung ins Entzündungsgebiet. Da es jedoch sowohl in der Literatur als auch in den Ergebnissen dieser Studie keine Hinweise auf einen absoluten Eisenmangel beim Fohlen gibt, sollte von einer Eisensupplementation in jedem Fall abgesehen werden.:1 Einleitung 1 2 Literaturübersicht 2 2.1 Vorkommen und chemische Eigenschaften von Eisen 2 2.2 Eisenmetabolismus 2 2.2.1 Absorption 2 2.2.2 Transport 3 2.2.3 Speicherung, Mobilisierung 4 2.2.4 Exkretion, Verlust 5 2.3 Physiologische Funktionen 6 2.4 Feststellung des Eisenstatus 7 2.5 Eisenbedarf des Pferdes 9 2.6 Eisengehalt von Futtermitteln 10 2.7 Eisenmangel 11 2.8 Supplementation von Eisen 12 2.9 Eisenüberschuss, Toxizität 12 2.10 Bakterieller Eisenstoffwechsel 13 2.11 Entzündung 14 2.11.1 Abszedierende Bronchopneumonie 15 2.12 Eisenstoffwechsel bei systemischer Entzündung 16 2.12.1 Ferritin als Akute-Phase-Protein 17 2.12.2 Serum-Eisen als Entzündungsmarker 17 3 Publikation 19 3.1 Vergleich des Eisenstatus im Serum von gesunden Fohlen und Fohlen mit Bronchopneumonie 19 4 Diskussion 30 5 Zusammenfassung 34 6 Summary 36 7 Literaturverzeichnis 38 Danksagung 47 / Introduction: Little is known about iron parameters in the blood of foals. The trace element iron is essential for mammals, its main task is the transport of oxygen. Horses take up the required iron with roughage, which has sufficiently high iron contents. The main molecule for iron storage is tissue ferritin. The serum ferritin found in the serum reflects the total amount of iron in the body. In the context of systemic inflammation, serum iron levels decrease as iron is redistributed to the tissues and migrates to the area of inflammation. There are no reference values for the parameters of iron metabolism for foals, for adult horses there is only a reference range for serum iron from 1.00-3.61 mg/L. There are no studies in which the iron parameters of foals were determined at the age of one to six months. Aim of the study: The aim of the present work was to investigate the parameters of serum iron metabolism in acute systemic inflammation in one- to six-month-old foals. In addition, it was to be determined to what extent this change in iron metabolism leads to a drop in serum iron levels. Animals, material, and methods: In this prospective study, EDTA whole blood and serum samples were collected from 66 healthy foals and 84 foals with acute systemic inflammation in the form of abscessed bronchopneumonia. The median age of the foals was 109 days. The diagnosis 'bronchopneumonia' was made by ultrasound diagnosis, the foals had a sonographically determined abscess score of more than 15cm as well as a rectally measured internal body temperature of more than 39.0 °C on the day of sampling. The healthy foals had an unremarkable clinical general examination and lung ultrasound on the day of sampling and in the previous and following week. In the laboratory, the serum amyloid A content was determined, a value > 7µg/mL confirmed the diagnosis of acute systemic inflammation. From the EDTA whole blood sample, the blood leucocyte count was determined within one hour by flow cytometry. The serum samples were analyzed in the LABOKLIN laboratory using the analyzer Cobas 8000 from Roche. Statistical analysis of the data was performed with SPSS (IBM Statistics 27). The data of the total population (n = 150) were not normally distributed. A Mann-Whitney U test was performed as a non-parametric test for two independent samples to determine significant differences between the groups. The significance level was set at p < 0.05. Results: The evaluation of the blood samples showed a median SAA level of 3.50 µg/mL for the healthy foals, the median of 541 µg/mL for the sick foals was significantly higher than in healthy foals. The determination of serum ferritin showed a median of 3.80 µg/l (IQR 2.00-4.40 µg/l) for the group of healthy foals, the median for the group of sick foals was significantly (p = 0.003) higher at 4.60 µg/l (IQR 2.48-6.40 µg/l). The serum iron values of the healthy foals were within the laboratory reference range for adult horses (median 1.57 mg/l; IQR 1.21-1.79 mg/l). The other blood iron values also corresponded to those of adult horses. The sick foals showed significantly lower serum iron levels (median 0.550 mg/l; IQR 0.368-0.778 mg/l), significantly higher ferritin and UIBC levels and significantly lower iron saturation. The evaluation of liver enzyme activities from the serum showed lower values on average for the sick foals than for the healthy foals for all measured parameters. For the trace element copper, the median of the healthy foals with 18.8 µmol/l (IQR 16.4-20.1µmol/l) is in the upper range of the reference values of 7.9-21µmol/l, the median of the sick foals with 25.7 µmol/l (IQR 23.1-29.0 µmol/l) is significantly higher than the values of the healthy foals (p < 0.001). Conclusion Acute systemic inflammation causes a drop in serum iron due to redistribution into the tissues and migration into the area of inflammation. However, since there is no evidence of an absolute iron deficiency in foals, either in the literature or in the results of this study, iron supplementation should be avoided in any case.:1 Einleitung 1 2 Literaturübersicht 2 2.1 Vorkommen und chemische Eigenschaften von Eisen 2 2.2 Eisenmetabolismus 2 2.2.1 Absorption 2 2.2.2 Transport 3 2.2.3 Speicherung, Mobilisierung 4 2.2.4 Exkretion, Verlust 5 2.3 Physiologische Funktionen 6 2.4 Feststellung des Eisenstatus 7 2.5 Eisenbedarf des Pferdes 9 2.6 Eisengehalt von Futtermitteln 10 2.7 Eisenmangel 11 2.8 Supplementation von Eisen 12 2.9 Eisenüberschuss, Toxizität 12 2.10 Bakterieller Eisenstoffwechsel 13 2.11 Entzündung 14 2.11.1 Abszedierende Bronchopneumonie 15 2.12 Eisenstoffwechsel bei systemischer Entzündung 16 2.12.1 Ferritin als Akute-Phase-Protein 17 2.12.2 Serum-Eisen als Entzündungsmarker 17 3 Publikation 19 3.1 Vergleich des Eisenstatus im Serum von gesunden Fohlen und Fohlen mit Bronchopneumonie 19 4 Diskussion 30 5 Zusammenfassung 34 6 Summary 36 7 Literaturverzeichnis 38 Danksagung 47
274

FBS free culture of porcine umbilical cord matrix cells

Parker, Steven W. January 1900 (has links)
Master of Science / Department of Animal Sciences and Industry / Duane L. Davis / The common choice of medium for culturing pig umbilical cord matrix stem cells (PUCs) is high glucose Dulbecco’s Minimum Essential Medium (HG-DMEM) supplemented with fetal bovine serum (FBS). FBS is a chemically undefined supplement that encourages attachment of explants and cells and is useful for long-term proliferation in an undifferentiated state. Removing FBS from the culture medium would decrease the possibility of microbial contamination and might produce more consistent results. A defined medium would facilitate experiments to determine requirements for specific growth factors and nutrients. Starting PUCs in a FBS-free environment proved to be a challenge. The results of 15 experiments testing various media, supplements, and culture conditions indicate that PUCs initially plated in an FBS-free environment do not attach as readily as those in HG-DMEM supplemented with FBS. PUCs were collected using enzyme digestion of the whole cord or by plating explants from the cord in culture medium. In the final experiment PUCs were seeded in 24-well plates (5.0 * 10[superscript]4 viable cells per well) with a collagen coating and cultured in Knock-out DMEM (KO-DMEM) with basic fibroblast growth factor (5ng/mL) and platelet derived growth factor (5ng/mL) in a low oxygen atmosphere (5% O[subscript]2/ 5% CO[subscript]2/ 90% N[subscript]2). The total non-adherent cell count at passage 1 was 1.78 * 10[superscript]5 +or- 3.68 * 10[superscript]4 and the total adherent cells were 2.58 * 10[superscript]5 +or- 9.29 * 10[superscript]4. The well confluence during initial cell proliferation appeared similar to cells cultured in the control media with 20% FBS (total adherent cells = 6.40 * 10[superscript]5 +or- S.E. 1.61 * 10[superscript]5 and total non-adherent cells = 2.88 * 10[superscript]5 + 7.60 * 10[superscript]4). However the number of adherent cells recovered for passage 2 was considerably less for cultures in FBS-free media than for the control group. Serum may affect attachment by providing attachment factors or it could change expression of integrins or other attachment molecules on the PUCs that enhance attachment to plastic or other substrates. In future studies the requirements for attachment of PUCs should be further evaluated.
275

Zinc in cerebrospinal fluid and serum in some neurological diseases

Palm, Ragnar January 1982 (has links)
The trace elements zinc and copper are essential components of many enzymes, some of which are of importance for the development and function of the central nervous system. Deficiency of the metals has been shown to lead to malformations and to the loss of myelin in animals. Earlier reports of zinc concentrations in the cerebrospinal fluid are few and the results variable. In multiple sclerosis and in epilepsy therapy with phenytoin there are varying reports of changes in serum concentrations of zinc and copper. A method was developed for the determination of zinc in cerebrospinal fluid by flame atomic absorption spectrophotometry utilizing a pulse nebulizer technique. Zinc and copper in serum were determined by flame atomic absorption spectrophotometry with conti nous aspiration. The normal concentrations of zinc in cerebrospi nal fluid was 0.16_+0.03 micromoles per litre (mean +_ S.D.). The zinc concentrations were correlated with protein and albumin concentrations in the cerebrospinal fluid but not with the serum zinc levels. In the patients with increased protein concentrations in the cerebrospinal fluid or with subarachnoid haemorrhage increased zinc levels were found. In 50 patients with multiple sclerosis lower serum concentrations of zinc were found compared to age and sex matched controls. In younger patients low serum levels of copper were also observed. There was no correlation between zinc and protein parameters in the cerebrospinal fluid of multiple sclerosis patients. In untreated epileptic males low serum zinc concentrations were observed. During the first 72 hours of phenytoin therapy increased serum concentrations of zinc and copper were found. during long-term therapy with phenytoin alone or in combination with other antiepileptic drugs there was an increased serum concentration of copper and ceruloplasmin but no change in zinc concentration compared with controls. / <p>Diss. Umeå, Umeå universitet, 1982, härtill 4 uppsatser</p> / digitalisering@umu
276

Health implications of dietary intake in infancy and early childhood

Öhlund, Inger January 2008 (has links)
Introduction: Swedish children are the healthiest in Europe. Through regular visits to well-baby clinics, infants and young children are checked and parents given information and advice on diet and other relevant matters for their child. For a long time, adequate nutrition during infancy and childhood has been focused on encouraging proper nutrition, preventing malnutrition and deficiency states, and obtaining optimal growth. Today, malnutrition and deficiency states in infants and children are rare. But other public health problems have arisen. Nutrition early in life is now thought to influence health and diseases even in adulthood. Thus promotion of a healthy diet in early life is important for preventing public health diseases such as iron deficiency, cardiovascular disease, obesity, and dental caries. Aims: This study investigates health implications of dietary intake in infancy and early childhood. More specific focus was on the associations between dietary fat intake and serum lipid levels in infants, early dietary intake, iron status, dental caries, and Body Mass Index (BMI) at 4 years of age. In addition, hereditary factors and changes over time were evaluated. Methods: Before 6 month of age, 300 healthy infants were recruited from well-baby clinics in Umeå. This thesis is based on secondary analysis of a prospective study in these infants run from 6-18 months and a follow-up of 127 of the children at 4 years. Between 6-18 months and at 4 years, dietary intakes were assessed, anthropometric measures performed, and venous blood samples taken. At 4 years, a dental examination was also performed and anthropometric data and blood samples were collected from parents and included in the study. Results: All but two infants were ever breastfed and at 6 months 73% were still breastfed. The quality of dietary fat was not within national recommendations. At 4 years, intake of vitamin D and selenium were below and intake of sugar and sweet products above the recommendations. In girls, but not boys, higher polyunsaturated fatty acid intake was associated with lower levels of total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B levels. Iron status of the children was generally good and no child had iron deficiency anaemia (IDA). Children’s haemoglobin (Hb) levels tracked from infancy to 4 years and correlated with their mother’s Hb. Fortified infant products and meat were important sources of iron at both 12 months and 4 years. Children with frequent intake of cheese had less caries in this population with low caries prevalence. We found higher protein intake over time to be associated with higher Body Mass Index (BMI) at 4 years and high BMI at 4 years was associated with high BMI at 6 mo. There was also an association between the BMI of the child and that of its parents. Conclusions: BMI of the child and parents (especially the father), and iron status at 6 months were predictors of these variables at 4 years of age. The quality rather than the quantity of dietary fat in infancy affected serum lipid values. Even in a healthy and well-nourished group of Swedish infants and young children, quality of food and intake of nutrients are important for current and later health of the child.
277

Effect of arthroscopic lavage and repeated through-and-through joint lavage on systemic and synovial serum amyloid A concentrations; as well as total protein concentrations, nucleated cell count and percentage of neutrophils in synovial fluid from healthy equine joints

2015 June 1900 (has links)
This research evaluated serum amyloid A (SAA) concentration in synovial fluid of healthy horses as a potential marker for use in the diagnosis and monitoring of horses with septic arthritis. The first study evaluated the effect of arthroscopic lavage of healthy joints on concentrations of systemic and synovial SAA; as well as total protein concentration, nucleated cell count and percentage of neutrophils in synovial fluid. The second study, evaluated the effect of repeated through-and-through joint lavage on SAA in systemic blood and SAA, total protein, nucleated cell count and percentage of neutrophils in synovial fluid from healthy joints. In the first study, middle carpal joints of 6 horses were randomly assigned to one of the following treatments 1) arthrocentesis (controls) or 2) arthroscopic lavage. A washout period of 30 days was allowed in between treatments. Synovial fluid and blood samples were collected at 0, 24, 48, 72, 96 and 120 h. Measurements included SAA in blood and synovial fluid, and total protein, nucleated cell count and percentages of neutrophils in synovial fluid. In the second study, one tarsocrural joint was randomly assigned to receive repeated through-and-through joint lavage at 0, 48 and 96 h in 6 horses. Synovial fluid and blood samples were collected at 0, 24, 48, 72, 96 and 120 h. Measurements included SAA in blood and synovial fluid, and total protein, nucleated cell count and percentages of neutrophils in synovial fluid. For this study, synovial fluid samples collected at time 0 were considered as control values. After arthroscopic lavage and repeated through-and-through joint lavage, systemic and synovial SAA did not increase from baseline values (except for systemic SAA at 24h after arthroscopic lavage and in controls). Total protein values were significantly increased at all time points after arthroscopic and through-and-through joint lavages (except at 96h on both lavage procedures) but not in controls. With both lavage procedures, nucleated cell count significantly increased from baseline values at all time points (except at 96h after through-and-through joint lavage). Percentage of neutrophils was significantly increased after arthroscopic lavage at all time points and only at 24h in controls; however, the percentages of neutrophils were not significantly increased after repeated through-and-through joint lavage. Synovial SAA was not affected by arthroscopic or repeated through-and-through joint lavage; however, synovial total protein and nucleated cell counts were significantly increased. Synovial SAA may be a valuable inflammatory marker that is not affected by procedures as arthroscopic or repeated through-and-through joint lavage in horses. Further validation of synovial SAA as a marker for evaluating the progression of septic joints while treatment is installed is warranted.
278

Mesoporous silica chips for harvesting the low molecular weight proteome from human serum

Hu, Ye 21 June 2010 (has links)
In this dissertation, mesoporous silica thin films with tunable features at the nanoscale were fabricated using the triblock copolymer template pathway, with the aim of specifically harvesting the low molecular weight peptides and proteins from human serum, which has been regarded as a potential source of diagnostic biomarkers for the early detection of disease. The superior properties of mesoporous silica have been demonstrated in applications which include chemical sensing, filtration, catalysis, drug-delivery and selective biomolecular uptake. These properties depend on the architectural, physical and chemical properties of the materials, which in turn are determined by the processing parameters in evaporation-induced self-assembly (EISA). Using the different polymer templates and polymer concentration in the precursor solution, various pore size distributions, pore structures and surface hydrophilicities were obtained and applied for nanotexture-selective recovery of low mass proteins. With the assistance of mass spectrometry and statistic analysis, we demonstrated the correlation between the nanophase characteristics of the mesoporous silica thin film and the specificity and efficacy of low mass proteome harvesting. In addition, to overcome the limitations of the pre-functionalization method in polymer selection, plasma ashing was used for the first time for the treatment of the mesoporous silica surface prior to chemical modification. Opposite surface charges due to the different functional groups used, resulted in a distinctive selectivity of the low molecular weight proteins from the serum sample. The mesoporous silica chips operate with extraordinary rapidity, high reproducibility, no sample pre-processing, and substantial independence from sample acquisition and storage temperature.In conclusion our study demonstrates that the ability to tune the physicochemical properties of mesoporous silica surfaces has the potential to promote the use of this material as a tool for the selective separation and concentration of the low molecular weight proteome from complex biological fluids. / text
279

Effect of sodium chloride supplementation on serum sodium concentration, cardiovascular function, and physical and cognitive performance

Pahnke, Matthew Daleon 26 October 2010 (has links)
These studies determined the effects of sodium chloride supplementation on serum and sweat sodium concentration, cardiovascular function, and physical and cognitive performance. Sweat sodium losses, alone, caused a significant decline in serum sodium concentration (-6.4±1.6 mEq/L, p=0.001) during 3h cycling in the heat in endurance-trained athletes with high sweat sodium losses. However, sodium chloride supplementation matching sweat sodium losses (NA; 5.9±1.5g NaCl/h) maintained serum sodium concentration. Post-exercise maximal cycling power declined and was significantly lower than pre-exercise in placebo (PL; p=0.012), but power was not significantly different in NA (p=0.057). Pre- to post-exercise response time during a Stroop Test improved in NA (p=0.009), while there was no change in PL (p=0.597). Post-exercise postural sway was less in NA vs. PL (p=0.044). Three days of sodium chloride supplementation (~15 g NaCl/d) resulted in a significant increase in plasma volume in healthy untrained males at rest (5.9±7.6 %) and during exercise at 60%VO₂peak (8.6±5.2 %) compared to PL. During NA, stroke volume was 10% higher during exercise vs. PL (139±27 vs. 126±24 ml/beat, respectively, p=0.004). Cardiac output was 8% higher in NA during exercise vs. PL (21.0±3.1 vs. 19.4±2.6 L/min, respectively, p=0.013). Mean arterial pressure during exercise was not different in NA vs. PL (p=0.548) as total peripheral resistance decreased (p=0.027) with the increased cardiac output. Sweat sodium concentration was 9% higher in NA vs. PL during exercise in the heat (70.4±19.5 vs. 64.5±21.7 mEq/L, p=0.044). In summary, serum sodium concentration declines when high sweat sodium losses are not replaced while hydration status is maintained. Acute sodium chloride supplementation during exercise which matches sodium losses maintains serum sodium concentration. This maintenance of serum sodium concentration results in both physical and cognitive benefits compared to when serum sodium concentration declines. Chronic intake of sodium chloride for 3 days increases plasma volume in healthy untrained men and improves cardiovascular function, as both stroke volume and cardiac output are increased, while oxygen consumption and blood pressure are unchanged. Therefore, acute and chronic sodium supplementation positively alters fluid and sodium balance which results in beneficial effects on physical and cognitive performance and cardiovascular function during exercise. / text
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DRUG MILK TO SERUM RATIO PREDICTION AND ONTOGENY OF CYP3A CLEARANCE PATHWAY AS A MODEL OF DRUG EXPOSURE IN THE DEVELOPING RAT

Abbassi, Maggie Magdi 01 January 2007 (has links)
Transfer of drugs into milk and the clearance of drugs in neonates are critical determinants of the exposure of infants to drugs in breast milk. Models predicting both parameters have been proposed. The objective of this dissertation is to test two models predicting milk to serum ratio and an ontogeny clearance model predicting clearance in the neonate. Predicted milk to serum ratio (M/S) values were generated according to the Atkinson and Begg model. The model did not adequately predict M/S when comparing the predicted values to observed values in the literature. The Fleishaker model was also tested. The model was able to predict whether the drugs appeared in milk by passive diffusion only or whether active transport processes were involved. This model, together with appropriate animal models, is useful in understanding the mechanism of drug transfer into milk. An ontogeny model that predicts clearance was proposed earlier by our laboratory. In order to test the model prediction and assumptions of constant microsomal protein and constant Km for an enzyme-substrate system with age, the male rat was used as an animal model. The ontogeny of Cyp3a1, Cyp3a2, Mdr1a and Mdr1b mRNA was examined in the male rat liver and intestine. The ontogeny pattern of Cyp3a2 mRNA, protein and in vitro Cyp3a activity were found to be similar in male rat liver. The microsomal protein content was found to vary with age in the liver. Km was found to be constant with age for the midazolam 4-hydroxylation by male rat liver microsomes. Scaling factors that extrapolate adult clearance to infant clearance were calculated from in vitro data. The model did not predict the in vivo oral clearance of midazolam for day 7 and 21 age groups from the 112 day age group (adult). The assumption that intestinal availability in the rat pups and adults was equal to unity might not be true resulting in overprediction of rat pup clearance when compared to the adult. Intestinal first pass effect for midazolam in adult rats might be significant. More experiments are needed to further test the model adequacy in clearance prediction.

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