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Quality of sputum collected for Acid-Fast Bacilli (AFB) test from patients at Dr. George Mukhari Hospital, PretotiaIqbal, R January 2010 (has links)
Thesis (M Med.(Family Medicine))--University of Limpopo, 2010. / OBJECTIVE: In order to obtain optimal results using sputum smear microscopy for acid-fast bacilli (AFB) detection in the diagnosis of pulmonary tuberculosis (PTB), good quality sputum with an adequate volume of at least 5.0ml is required. An inadequate amount of sputum sample may result cases of active PTB being missed. This study was aimed at showing that a single sputum sample of at least 5.0ml would lower the chances of missing active PTB cases, and increase sputum smear positivity by microscopy thus enabling prompt treatment of PTB, and restricting its transmission.
METHODS: An analytical cross sectional study was carried out at Dr George Mukhari Hospital in Pretoria, South Africa. Two sputum samples, one of 5.0ml and the other with 2.0ml were collected from each adult patient suspected of having active PTB. Sputum collection was supervised and patients were given instructions on how to enhance sputum expectoration. Sputum samples were processed using the N-acetyl-L-cysteine (NaLc-NaOH) method and stained with Auramine O. Sputum analysis was done with the aid of fluorescence microscopy. Following microscopy, both the 2.0ml and 5.0ml specimens were sent for culture using the Middlebrook broth medium, and culture results were available after 6-8 weeks. Using the culture results as gold standard, the yield through microscopy of the 2.0ml specimen versus the 5.0ml specimen for each patient were compared and analysed.
RESULTS: A Total of 330 sputum samples were analysed of which 77 were found to be culture positive. A sensitivity of 76.6% and specificity of 99.6% was obtained for AFB test in the 5.0ml specimens; while in the 2.0ml samples the sensitivity was 75.3%, with a specificity of 99.2%. The difference in the smear positivity rate of 76.6% obtained using the 5.0ml sputum specimen compared to the 75.3% obtained using the 2.0ml specimen from patients suspected of having TB in this study was statistically insignificant – ascribable to the small sample size.
CONCLUSION: In this study, the volume of sputum collected did not determine a better AFB test yield in the diagnosis of pulmonary tuberculosis in patients suspected of having TB.
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Aflatoxin B1 Metabolism in Mammalian Pulmonary TissueEichelberger, J. Michael 01 May 1997 (has links)
Aflatoxin B1 (AFB1) is a potent dietary hepatocarcinogen and may be a lung carcinogen when inhaled. To study the relative ability of lung and liver to metabolize AFB1, a susceptible (Swiss-Webster rat) and resistant species (Syrian golden hamster) were pretreated with inducing agents in order to identify specific AFB1 metabolizing enzymes in each tissue.
Analysis of AFB1-exo-epoxide (AFBO) formation, O-dealkynation assays, and protein immunoblots demonstrated that cytochrome P450 (CYP) 1A proteins were overexpressed in both the lung and liver of hamsters pretreated with 3-methylchyolanthrene (3-MC). Only CYP1A1 was expressed in the lung and there was no indication that this protein was involved in AFB1 activation. CYP1A2, on the other hand, was induced in the liver and this correlated well with both increasing protein activity and AFBO formation. It would appear that CYP1A2 is important in activating AFB1 in hamster liver.
Although the hamster is resistant as compared to the rat, AFBO formation was higher in both the lung and liver of the hamster compared to the rat. Glutathione S-transferase (GST) Yc subunits were detected in the lung and liver of both species but were not induced by the inducing agents used in these experiments.
Following intratracheal injections of [3H]AFB1, in the rat, specific activity was localized in the liver. Only a fraction of the activity was detected in the lung. Of four inducing agents used, only pretratment with phenobarbital (PB) showed increased AFB1-DNA binding in either lung or liver. This correlated with increased CYP2B1 protein levels in both lung and liver, as well as increased CYP2B1 activity and AFBO formation in the liver.
Cooxidation of AFB1 by purified prostaglandin H-synthase was shown to produce AFBO but microsomal fractions from rabbit lung and liver failed to show detectable levels of AFBO formation by this cooxidative pathway. Neither purified 5-lipoxygenase or cytosolic fractions from rabbit lung or liver showed detectable levels of LOX mediated cooxidation of AFB1 to AFBO.
These studies demonstrate that hamster resembles the human in regard to AFB1 activation in the liver, but that a different as yet unknown enzyme is responsible for hamster lung AFB1 activation. Further evidence that the rat is a poor model for human AFB1 metabolism was demonstrated with the fact that rat activates AFB1 with CYP2B1, a protein unknown in humans.
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The Effect of Chronic Obstructive Pulmonary Disease on Laryngopharyngeal Sensitivity and Swallow FunctionClayton, Nicola Ann January 2007 (has links)
Masters of Science in Medicine / The relationship between COPD and laryngopharyngeal sensitivity has not been previously determined. Limited research into the relationship between COPD and swallow function suggests that patients with COPD are at increased risk of aspiration. One possible mechanism for this is a reduction in laryngopharyngeal sensitivity (LPS). Reduced laryngopharyngeal sensitivity (LPS) has been associated with an increased risk of aspiration in pathologies such as stroke, however impaired LPS has not been examined with respect to aspiration risk in COPD. The Aims of this study were to investigate the effect of COPD on laryngopharyngeal sensation using Laryngopharyngeal Sensory Discrimination Testing (LPSDT) and to determine whether a relationship between LPS and swallow function in patients with proven COPD exists. Method: 20 patients with proven COPD and 11 control subjects underwent LPSDT utilising an air-pulse stimulator (Pentax AP4000) via a nasendoscope (Pentax FNL10AP). The threshold of laryngopharyngeal sensation was measured by the air pressure required to elicit the laryngeal adductor reflex (LAR). A number of further examinations were also completed for COPD subjects. These included respiratory function testing, self-reporting questionnaire on swallowing ability (SSQ), bedside clinical examination of swallowing (MASA) and endoscopic assessment of swallowing (EAS). Results: subjects with COPD had a significantly higher LAR threshold when compared to their normal healthy counterparts (p<0.001). Positive correlations were identified for the relationships between MASA score and EAS results for presence of laryngeal penetration / aspiration (p<0.04), vallecular residue (p<0.01) and piriform residue (p<0.01). Conclusion: Patients with COPD have significantly reduced mechanosensitivity in the laryngopharynx. Patients with COPD also have impaired swallow function characterised primarily by pharyngeal stasis. These changes may place patients with COPD at increased risk of aspiration.
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Influences on the incidence of clinical deep vein thrombosis and pulmonary embolism in a prospectively collated population of 21,000 neurosurgical inpatientsSmith, Sarah Faith January 2001 (has links)
Records of all neurosurgical inpatients admitted to Royal North Shore Hospital since 1976 have been prospectively kept in a relational database. Demographic details, diagnoses, operations and complications have been entered continuously since 1982 by the author of this study. Complications are monitored at monthly review meetings attended by medical staff. The recurrence of deep vein thrombosis (DVT) and pulmonary embolism (PE) at these meetings, despite continual improvements in patient care, prompted this study. It aims to use the database to study changes in the incidence of DVT and PE over the previous twenty years; to find what database variables predict these complications; and whether use of mechanical and pharmacological agents has had an impact on DVT and PE rate. Univariate analysis of the incidence of DVT and PE by age, sex, length of stay (LOS), admission month, diagnosis, operation and surgeon over time was run. Any significant variables were then analysed by multivariate logistic regression. The DVT rate was low by world standards, but rose from 0.6% in 1979-83 to 1.2% in 1984-88, then rose exponentially to 3.60% in 1994-98 with a significantly increasing trend over the twenty years (c2 MH =114.20, with IDF, P<0.001). PE rate doubled significantly over the twenty years from 0.6% to 1.2% (c2 MH =17.94 with 1DF, P<0.001). Age, LOS, diagnosis, operation and surgeon were significant predictors of DVT and PE. After adjustment for LOS, time period and age, vascular surgery was found to be the strongest predictor of DVT (OR=2.82, 95% CI: 2.08-3.82, c2 =43.91, P<0.01). Vascular diagnosis was the strongest diagnosis predictor. No effect of sex or month of admission was shown. After adjustment for LOS, time period and age, spinal fusion was the strongest predictor of PE (OR=4.04, 95% CI: 1.81-9.03). Anterior communicating artery aneurysm was the diagnosis most highly associated with PE. The rise in DVT rate may be due to increased complexity of surgical and nursing management, and some screening of patients with the introduction of duplex scanning. The doubling of PE rate is unexplained. The risk of brain or spinal cord haemorrhage makes prophylactic anticoagulation a difficult choice. This study reveals groupings which can be used to determine appropriate prophylaxis. Use of mechanical and pharmaceutical agents is not recorded consistently in the database, but it is known approximately when they were introduced. No impact on the rate of DVT and PE can be demonstrated by these agents. More vigilant and widespread use of mechanical prophylaxis might be just as effective in controlling DVT and PE.
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The evolution of a physiological system: the pulmonary surfactant system in diving mammals.Miller, Natalie J January 2005 (has links)
Pulmonary surfactant is a complex mixture of lipids and proteins that lowers surface tension, increases lung compliance, and prevents the adhesion of respiratory surfaces and pulmonary oedema. Pressure can have an enormous impact on respiratory function, by mechanically compressing tissues, increasing gas tension resulting in increased gas absorption and by increasing dissolved gas tensions during diving, resulting in the formation of bubbles in the blood and tissues. The lungs of diving mammals have a huge range of morphological adaptations to enable them to endure the extremely high pressures associated with deep diving. Here, I hypothesise that surfactant will also be modified, to complement the morphological changes and enable more efficient lung function during diving. Molecular adaptations to diving were examined in surfactant protein C (SP-C) using phylogenetic analyses. The composition and function of pulmonary surfactant from several species of diving mammals was examined using biochemical assays, mass spectrometry and captive bubble surfactometry. The development of surfactant in one species of diving mammal (California sea lion), and the control of surfactant secretion using chemical and mechanical stimuli were also determined. Diving mammals showed modifications to SP-C, which are likely to lead to stronger binding to the monolayer, thereby increasing its fluidity. Phospholipid molecular species concentrations were altered to increase the concentration of more fluid species. There was also an increase in the percentage of alkyl molecular species, which may increase the stability of the monolayer during compression and facilitate rapid respreading. Levels of SP-B were much lower in the diving species, and cholesterol was inversely proportional to the maximum dive depth of the three species. Surface activity of surfactant from diving mammals was very poor compared to surfactant from terrestrial mammals. The newborn California sea lion surfactant was similar to terrestrial mammal surfactant, suggesting that these animals develop the diving-type of surfactant after they first enter the water. The isolated cells of California sea lions also showed a similar response to neuro-hormonal stimulation as terrestrial mammals, but were insensitive to pressure. These findings showed diving mammal surfactant to have a primarily anti-adhesive function that develops after the first entry into the water, with a surfactant monolayer, which would be better suited to repeated collapse and respreading. / Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2005.
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Association and interaction of serum albumin with lung surfactant extract /Vidyasankar, Sangeetha, January 2004 (has links)
Thesis (M.Sc.)--Memorial University of Newfoundland, 2005. / Bibliography: leaves 117-129.
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Evaluation of multislice spiral CT for the diagnosis of pulmonary embolismCoche, Emmanuel 28 April 2005 (has links)
Pulmonary embolism (PE) is a severe frequent disease with lack of
specific symptoms and represents a major diagnostic challenge. In the past
few years, single-slice spiral CT angiography has gained acceptance as a
minimally invasive method of evaluating patients with suspicion of PE. The
main limitation of single-slice spiral CT resides in the poor detection of subsegmental
or more distal PE. This limited detection is not explained by an
insufficient vascular distension during spiral CT acquisition but probably by an
insufficient spatial resolution. Moreover, in some situations spiral CT is
penalized by pulmonary angiography which is an imperfect gold standard.
Today Multislice CT can acquire 2 up to 64 slices in a single rotation
with isotropic resolution. This technique can cover the entire chest in 1-mm
slice thickness or less, in one short breath-hold and allows a better analysis of
peripheral pulmonary arteries with a better depiction of sub-segmental and
peripheral clots. It also reduces or eliminates artefacts produced by patient
movement and decreases the x-ray tube heating that can constrain singleslice
scanning parameters. Acquisition of the lower extremities can be
performed after chest CT, allowing detection of deep vein thrombosis and one
stop shopping of the venous thromboembolic disease. The diagnostic
accuracy of multislice CT is probably similar or superior to pulmonary
angiography with an inferior delivered radiation dose, a better detection of
alternative diagnoses and a continuous decrease of contrast medium injected.
Last refinements in CT technology opens new frontiers for a functional
approach of PE and predict its prognosis.
For all the above-mentioned reasons, it seems obvious that multislice
CT will definitively replace pulmonary angiography for diagnostic purposes
and will represent a superb tool to better understand the physiopathology of
this frequent and potentially life-threatening disorder.
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Volumetric capnography in the diagnosis and the therapeutic monitoring of pulmonary embolism in the emergency departmentVerschuren, Franck 07 December 2005 (has links)
CO2 and its influence on environmental and ecological processes focuses the attention of all current media. In the medical area, expired CO2 measurement with Capnography has gained acceptance for all patients needing clinical monitoring and supervision. But recent research works are showing the promises of CO2 as a diagnostic tool or therapeutic monitoring. In this case, measurement of expired CO2 in function of the expired volume, called Volumetric Capnography, has a theoretical better performance than the traditional time-based Capnography. When expired CO2 data are combined to arterial CO2 sampling, the clinician faces breath-by-breath curves, which give a bedside knowledge of the pulmonary ventilation and perfusion status of his patient.
Pulmonary embolism is a particular application of Volumetric Capnography. This frequent and challenging disease is characterized by impaired relationships between the pulmonary ventilation and perfusion, going from deadspace to shunt. Volumetric Capnography deserves a careful attention in this area, since its combination with other clinical or biological signs could become part of a diagnostic procedure, either for the detection of the disease when capnographic parameters are clearly impaired, or for ruling out this diagnosis when Volumetric Capnography analysis is normal. In the same way, monitoring the efficacy of thrombolytic therapy when pulmonary embolism is massive is another particular interest for expired CO2 measurement.
Physicians working in the Emergency Department demand performing devices for improving patient care. Such devices can be particularly adapted to daily practice if they can be used by the bedside, if they are non-invasive, safe, efficient, feasible, and applicable to non-intubated patients. Volumetric Capnography, which seems to answer those requirements, will certainly deserve growing attention and interest in the future as a direct application of pulmonary pathophysiology. Even if Volumetric Capnography is still at the frontier between clinical research and clinical practice, let us hope that the studies presented in this thesis will improve the clinical acceptance of this attractive technology.
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Characterizing the Effects of Respiratory Motion on Pulmonary Nodule-like Objects in Computed TomographyHamilton, Michael 01 January 2011 (has links)
Lung nodule volumetry is used to diagnose the likelihood of malignancy in nodules detected during thoracic CT scans. These measurements are unreliable when the patient is subject to respiratory motion. We seek to understand the relationship between reconstructed images and the actual size of nodules subject to motion induced by quiet breathing. CT images of solid spheres of varying size and composition were acquired while travelling through a known path to approximate the motion of a pulmonary nodule during respiration. The measured size of the sphere’s image was found to increase non-linearly with speed. However, these relationships were dependent on the CT number of the sphere and the reconstruction filter used to generate the image. From these results we expect that for a specific CT number we can estimate the size of an object from a CT image if the speed of the object at the time of the scan is known.
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Lung Complications in Adenosine Deaminase (ADA) Deficiency: A Mouse Model for the Human DiseaseDhanju, Rupreet 21 November 2012 (has links)
Recently, we discovered patients with inherited adenosine deaminase (ADA) deficiency are predisposed to pulmonary alveolar proteinosis (PAP). PAP is characterized by the accumulation of surfactant in the alveoli. To overcome ethical issues and limited patient samples, animal models are often utilized. Here, I investigated the lung abnormalities in ADA deficient (ADA -/-) mice, which suffer from severe hypoxia, till their death at 3 weeks. I hypothesized that, similar to ADA-deficient patients, ADA -/- mice demonstrate evidence of PAP. Indeed, electron microscopy showed thickening of type I cells, accumulation of apoptotic foamy alveolar macrophages, cholesterol and lipoproteinaceous material that is periodic-acid Schiff (PAS) positive and diagnostic of PAP. Moreover, the pulmonary abnormalities were corrected with supplementation of ADA. In conclusion, we demonstrated evidence of PAP in ADA -/- mice for the first time and their suitability to study pathogenesis of PAP in ADA deficiency.
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