Introduction: It is recommended to place all the vacuum tubes directly on a sample cradle after vein puncture to prevent analytic error. This recommendation is not always easy to follow because the samples are taken by different professionals under different situations.  The three most common analyses, platelets count, haemoglobin and prothrombin time were tested.  Therefore, it was interesting to compare results from the three most common analyses with or without sample cradle, to evaluate the influence of this step on the result. Methods: Three analyses were preformed, using blood from 50 different persons. Each person gave two vacuum tubes, each contained 4.5mL of venous blood for the study. Tubes containing EDTA were used for platelet counts and measurement of haemoglobin and tubes containing citrate were used for prothrombin time-analysis. One of the tubes was placed, as recommended, directly on the sample cradle while the other tube was placed flat on a bench for 10 minutes before it was placed on the sample cradle. Results: There was a clear difference in platelet counts with and without immediate cradling but only minor difference between the results for haemoglobin and International Normalized Ratio. Conclusion: Some analyses seem to be more sensitive for variation in cradling than others. For platelet count it was important to immediately rock the tubes but for determination of prothrombine time and hemoglobin it had a small impact. The small impact on the results is probably due to the efficiency of the anticoagulant in the vacuum tubes.

The Batopilas Mining District was a major silver producer, with estimated historic production of more than 300 million ounces. Orebodies consist of high-grade silver in the forms of native silver, acanthite and proustite hosted dominantly in calcite veins. Recent exploration has facilitated the reexamination of the geologic features and origin of the enigmatic native silver district. Sulfur, lead, and strontium isotopic studies have been conducted to constrain the fluid and metal sourcing. [delta]³⁴SvCDT isotope signatures for galena, sphalerite and pyrite range from -8 to -2, -6 to 0, and -5 to 3°/₀₀, respectively. A fractionation temperature of 227±25 °C can be obtained using average sulfur isotope values for galena and sphalerite. Galena lead isotopic values show two distinct signatures. Samples of massive-replacement style mineralization have ²⁰⁶Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb, and ²⁰⁸Pb/²⁰⁴Pb values of 18.742 and 18.747, 15.611 and 15.618, and 38.512 and 38.535, respectively. For vein samples, the corresponding values range from 18.799 to 18.817, 15.623 to 15.639, and 38.603 to 38.655. The lead isotopic signatures for vein galena have lower thorogenic lead content than other ore deposits in the Sierra Madre Occidental, suggesting a different source of metals. Vein calcite samples have ⁸⁷Sr/⁸⁶Sr isotopic compositions ranging from 0.707551 to 0.70590 (±0.000009) and Sr concentrations ranging from 51 to 246 ppm. These vein components may reflect mixed deep-marine sedimentary and Precambrian basement sources. A reconnaissance fluid inclusion study was conducted to better constrain fluid temperature and composition. The minerals studied included quartz, fluorite, and two types of sphalerite. The average eutectic temperatures obtained are -38°C, -31°C, and -43°C, respectively, indicating a complex mineralizing brine. Homogenization temperatures averaged 143°C, 165°C, and 174°C, and the NaCl equivalent weight percents averaged 4, 7, and 17, respectively. Fluids involved in vein mineralization are different from those typical of epithermal vein Ag-Au deposits, and may represent sedimentary brines that have circulated through the underlying basement. / text

Tissues are not solely composed of cells. The extracellular matrix is important for the cell well-being and cell-cell communication. The glycosaminoglycan hyaluronan (HYA) is a widely distributed extracellular matrix (ECM) component. The molecule has prominent physicochemical properties, foremost viscoelastic and osmotic, but participates in many biological processes such as cell migration, proliferation, tissue turnover, wound healing and angiogenesis. HYA is synthesised by either of three different hyaluronan-synthesising enzymes, HAS1-3, and its main ligand is the transmembrane receptor CD44. In the heart and vessels the matrix components are of great importance for endurance and elasticity which are prerequisites for a normal function. The aims of the study were to describe the distribution of HYA and its receptor CD44 in normal cardiovascular tissue and to investigate the ECM composition in myocardial hypertrophy. Normal conditions were studied in a rat model. These studies showed that the tunica adventitia in almost all vessels stained strongly for HYA. The expression in the tunica intima and media on the venous side, differed between the vessels and was almost absent on the arterial side. In the adult animals only minute amounts of CD44 were detected. The expression of both HYA and CD44 was increased in newborn rats. In the heart HYA was unevenly distributed in the interstitium. Strong HYA-staining was seen in the valves and in the adventitia of intramyocardial vessels. Almost no CD44-staining was observed. Notably, there was no obvious difference between newborn and adult animals. In an experimental rat model of pressure-induced cardiac hypertrophy the mRNA-levels of HAS1, HAS2, CD44, basic Fibroblast Growth Factor (FGF-2) and Fibroblast Growth Factor Receptor-1 (FGFR-1) were elevated on day 1 after aortic banding. HAS2, CD44 and FGFR-1 were at basal levels on day 42. The HYA-concentration was significally elevated on day 1. HYA was detected in the interstitium by histochemistry and CD44 was detected mainly in and around the intramyocardial vessels. The HYA-staining was increased in myectomi specimens from patients with HCM compared to controls. HYA was detected in the interstitium, in fibrous septas and in the adventitia of intramyocardial vessels. No CD44 was detected in HCM or in control specimens. Our results indicate that HYA and CD44 play an active role in the maturing vessel tree and that the ECM content of HYA is increased in experimental myocardial hypertrophy and human hypertrophic cardiomyopathy.

This thesis describes the successful development and initial evaluation of a proof-of-concept wireless monitoring system for improving the effectiveness and safety of pneumatic compression therapy to help prevent deep vein thrombosis (DVT). In the development, an important objective was to make feasible the practical and commercial deployment of such improved therapy systems in future, by focusing on a cost-effective design and implementation. Over the years, pneumatic compression has been shown to be an effective solution for the prevention of DVT. However, different problems and complications related to the use of commercial pneumatic compression de-vices that typically include automatic pressure controllers and pneumatic compression sleeves have been reported. For example, one study reported a high percentage of improperly applied or nonfunctional pneumatic compression devices in routine usage. Technical problems, non-compliance, and human error were identified as the causes behind the failed therapies. Also, it was reported that dedicated in-service instruction did not improve the proper use of the pneumatic compression controllers and sleeves. In another study, significant unanticipated variations between expected and delivered pneumatic compression therapy were reported: expected therapy delivered only an average of 77.8% of the time during the therapy, and much of the time key values related to the outcome of the therapy were found to have variations great than 10%. Specific hazards have also been reported. For example, one patient developed acute compartment syndrome after wearing a pair of pneumatic compression sleeves with faulty pressure release valves. In another case, epidural analgesia masked a malfunction resulting from a reversed connection between four-way plastic tubing of the sleeves and the controller, exposing a patient to a hazardous pressure of around 300mmHg,blocking all blood flow for a prolonged period of time. Newer models of pneumatic compression sleeves and controllers from various manufacturers claim to improve therapy by, for example, increasing the peak blood flow velocity. However, there is no evidence in the published literature to support such claims. A published review of the literature from1970-2002 reached the conclusion that the most important factors in im-proving therapy with pneumatic compression devices, particularly during and after surgery, were the degree of conformance of delivered therapy to the prescribed therapy, patient compliance, and the appropriateness of the site of compression. The inability to monitor delivered therapy and patient compliance remains a problem in efforts to improve pneumatic compression therapy. The above-described problems were addressed in the successful development of the innovative prototype described in this thesis. This wireless monitoring system should improve the effectiveness and safety of pneumatic compression therapy. Also, innovative aspects of the system design allow for cost-effective integration into existing commercial controllers and sleeves. For example, an innovative and potentially patentable usage and reprocess indicator was developed for pneumatic compression sleeves to significantly improve their safety and to reduce their cost of use per patient.

No description available.

No description available.

No description available.

No description available.

Atrial fibrillation is the most common sustained arrhythmia; however, its mechanism is not well understood. Several conditions such as valvular disease, heart failure, and hypertension predispose to atrial fibrillation. Identifying the electrophysiological substrate in these clinical conditions would yield insight into the mechanism of atrial fibrillation and aid in developing strategies to prevent or cure it. Rheumatic mitral stenosis is associated with high prevalence of atrial fibrillation. While atrial stretch itself may be adequate to explain the occurrence of atrial fibrillation in this population, it is not known if the disease process would remodel the atria so as to increase its propensity. Chapters 2 and 3 present the results of the studies evaluating the substrate for atrial fibrillation in both the left and right atria in rheumatic mitral stenosis. These studies have demonstrated extensive conduction abnormalities both regional and site specific associated with low voltage area and scar. Despite the prolonged atrial refractoriness, the propensity for atrial fibrillation was increased; lending support to the theory that structural remodelling associated with conduction abnormalities plays a greater role in the substrate predisposing to atrial fibrillation. Chapters 4 and 5 present the results of the studies evaluating the immediate effects of chronic atrial stretch reversal on the atrial electrical remodelling. These studies demonstrated that immediately after percutaneous mitral commissurotomy there was decrease in P wave duration, improvement in site specific conduction delay and conduction velocity associated with increase in the voltage. However, there was no change in atrial refractoriness. Chapter 6 studies the substrate long-term after reduction of stretch. There was further increase in conduction velocity and voltage associated with decrease in atrial refractoriness and conduction delay across the crista terminalis. These observations suggest that strategies aimed at reducing atrial stretch in different disease conditions would potentially decrease the burden or prevent atrial fibrillation. There is mounting evidence of the effect of stretch on the atria; however, the effect of stretch on the triggers of atrial fibrillation has not been evaluated before. Chapter 7 and 8 present the results of the study examining the effect of acute and chronic stretch on human pulmonary veins. Simultaneous pacing of the right ventricle and pulmonary vein induced acute stretch. The effect of chronic stretch was evaluated in patients with mitral stenosis. The atrial refractoriness was abbreviated in acute stretch while it was prolonged in the chronic form. Nevertheless, both resulted in marked pulmonary vein conduction abnormalities that were pronounced with chronic stretch and extra-stimuli. Additionally, structural remodelling was seen with chronic stretch. These abnormalities implicate stretch in the milieu for re-entry and pulmonary vein arrhythmogenesis in conditions predisposed to atrial fibrillation. In summary, this thesis has evaluated the effects of stretch on the substrate and triggers of atrial fibrillation. It provides evidence for the importance of structural changes and the associated abnormalities in conduction in predisposing to atrial fibrillation. These observations may be important in the development of tools to treat, cure and prevent atrial fibrillation. / Thesis (Ph.D.) -- University of Adelaide, School of Medicine, 2008

Made available in DSpace on 2014-06-11T19:32:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-05-24Bitstream added on 2014-06-13T21:04:42Z : No. of bitstreams: 1 matida_ck_dr_botfm.pdf: 889840 bytes, checksum: e2fb39fd0a8e59a674752ea187a4c74b (MD5) / A importância do estudo da trombose venosa profunda (TVP) em crianças e adolescentes reside no impacto desta doença sobre a qualidade de vida desta população, tendo em vista sua longa expectativa de vida e a morbidade associada ao tromboembolismo venoso. Com o passar dos anos, a síndrome pós-trombótica e a recorrência podem deixar sequelas que vão desde dor crônica nos membros, edema e até úlceras de difícil cicatrização. A TVP em crianças está sendo melhor estudada nos últimos anos. Até então, seu diagnóstico e tratamento eram baseados em experiências individuais, pequenas séries de casos ou extrapolados das recomendações para adultos. Realizamos a presente revisão para melhor compreensão da epidemiologia, fisiopatologia, etiologia, diagnóstico, tratamento desta doença / The study of deep vein thrombosis (DVT) in children and adolescents assesses the important impact of this disease on the quality of life of this population considering its long life expectancy and morbidity associated to venous thromboembolism. Within the years, the pos-thrombotic syndrome and recurrence can cause sequelae including chronic lower limb pain, edema and even hard cicatrization ulcer. Recently, DVT in children has been studied more appropriately. Previously, its diagnosis and treatment were based on individual experience, some serial cases or comparisons with recommendations to the adult treatments. This present study has been presented to better comprehend the epidemiology, physiopathology, etiology, diagnosis, treatment and prophylaxis of the deep vein thrombosis