Biomedical Science
http://hdl.handle.net/10211.3/214755
2024-03-29T07:46:03ZMultivariate spectrophotometric assay for cerebrospinal fluid bilirubin
http://hdl.handle.net/10211.3/128857
Multivariate spectrophotometric assay for cerebrospinal fluid bilirubin
Smith, Andrew Charles
Cerebrospinal fluid (CSF) contains various pigments that may contribute to discoloration
termed xanthochromia. These pigments include bilirubin, hemoglobin, and proteins.
Detection of bilirubin in CSF is an indication of in vivo breakdown of hemoglobin, and
has been used as a diagnostic tool for detecting subarachnoid hemorrhage. Current
biochemical and visual techniques lack the sensitivity and specificity to detect bilirubin at
concentrations typically found in CSF following a bleed. In the direct spectral analysis of
CSF, oxyhemoglobin greatly interferes with the absorption peak of bilirubin. This study
attempts to use linear algebra to calculate bilirubin concentration in the presence of
abnormal oxyhemoglobin and protein concentrations. The multiwavelength method was
validated using a cohort of confirmed subarachnoid hemorrhage patients, as well a group
of controls. A sensitive High Performance Liquid Chromatography method was
developed for bilirubin as a gold standard reference method. Regression analysis showed
that the multivariate method correlated well to the HPLC method. Receiver Operator
Characteristic Curve analysis showed high specificity and sensitivity, suggesting future
use of this assay as a tool in clinical diagnosis of subarachnoid hemorrhage.
2013-01-01T00:00:00ZMolecular epidemiological study of multi-strain Salmonella outbreaks in Monterey County, California
http://hdl.handle.net/10211.3/99865
Molecular epidemiological study of multi-strain Salmonella outbreaks in Monterey County, California
Ungermann, Ashley Christina
Salmonella infections are among the most common causes of food-borne gastroenteritis.
Between 2004 and 2005, three outbreaks of human Salmonellosis (serotypes
Brandenburg, Saintpaul, and Typhimurium) occurred in correctional facilities located in
Salinas, CA. In total, 92 outbreak and non-outbreak associated Salmonella isolates were
collected to compare local antmicrobial resistance rates, differentiate outbreak strains,
and identify any correlations between particular strains and antimicrobial resistance
phenotypes. Our results indicated a significantly higher antimicrobial resistance rate in
Monterey County isolates compared to the reported national average, including an
increasing rate of cephalosporin resistance and resistance to five or more antimicrobial
subclasses over time. Pulsed-field gel electrophoretic analysis of outbreak isolates
indicated several closely related strains within the Brandenburg and Typhimurium
outbreaks. No correlations between genetic profiles and antimicrobial resistance was
observed. Antimicrobial resistance testing of Salmonella samples should be strongly
emphasized, particularly for isolates collected from persons or animals located in the
agricultural areas of Monterey County.
2010-01-01T00:00:00Z