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Biomedical subjects

Susan Lin

Publications and source records attributed to Susan Lin.

11 recordsLinked to original sources

Evaluation of uncertainty in quantitative real-time PCR.

Quantitative real-time PCR is one of the newer methods for measurement of the amount of nucleic material in biological systems. However, reliable measurement requires an appropriate estimation of uncertainty and this paper has developed the uncertainty budget associated with this procedure using as an example, data from a quantitative real-time PCR method for the enumeration of Campylobacter jejuni. This uncertainty is relatively large and for instance, a measured result of 151 units of DNA would have a 95% confidence interval of +/-84 units of DNA with the main sources of uncertainty being the measurement of the threshold cycle (Ct) value, the predicted DNA content of the unknown sample from the calibration line and the molar absorbance value for DNA.

Campylobacter jejuni↗

Cognitive dysfunction is associated with poor diabetes control in older adults.

OBJECTIVE: To evaluate the association between cognitive dysfunction and other barriers and glycemic control in older adults with diabetes. RESEARCH DESIGN AND METHODS: Patients over the age of 70 years presenting to a geriatric diabetes clinic were evaluated for barriers to successful diabetes management. Patients were screened for cognitive dysfunction with the Mini Mental State Examination (MMSE) and a clock-drawing test (CDT) scored by 1) a method validated by Mendez et al. and 2) a modified CDT (clock in a box [CIB]). Depression was evaluated with the Geriatric Depression Scale. Interview questionnaires surveyed activities of daily living (ADLs) and instrumental ADLs (IADLs), as well as other functional disabilities. RESULTS: Sixty patients (age 79 +/- 5 years, diabetes duration 14 +/- 13 years) were evaluated. Thirty-four percent of patients had low CIB (< or =5), and 38% of patients had low CDT (< or =13). Both CIB as well as CDT were inversely correlated with HbA(1c), suggesting that cognitive dysfunction is associated with poor glycemic control (r = -0.37, P < 0.004 and r = -0.38, P < 0.004, respectively). Thirty-three percent of patients had depressive symptoms with greater difficulty completing the tasks of the IADL survey (5.7 +/- 1.7 vs. 4.6 +/- 2.0; P < 0.03). These older adults with diabetes had a high incidence of functional disabilities, including hearing impairment (48%), vision impairment (53%), history of recent falls (33%), fear of falls (44%), and difficulty performing IADLs (39%). CONCLUSIONS: Older adults with diabetes have a high risk of undiagnosed cognitive dysfunction, depression, and functional disabilities. Cognitive dysfunction in this population is associated with poor diabetes control.

Aged↗

Surface-active fungicidal D-peptide inhibitors of the plasma membrane proton pump that block azole resistance.

A 1.8-million-member D-octapeptide combinatorial library was constructed in which each member comprised a diversity-containing N-terminal pentapeptide and a C-terminal amidated triarginine motif. The C-terminal motif concentrated the library members at the fungal cell surface. A primary screen for inhibitors of Saccharomyces cerevisiae and Candida albicans growth, together with an in vitro secondary screen with the S. cerevisiae plasma membrane ATPase (Pma1p) as a target, identified the antifungal D-octapeptide BM0 (D-NH(2)-RFWWFRRR-CONH(2)). Optimization of BM0 led to the construction of BM2 (D-NH(2)-RRRFWWFRRR-CONH(2)), which had broad-spectrum fungicidal activity against S. cerevisiae, Candida species, and Cryptococcus neoformans; bound strongly to the surfaces of fungal cells; inhibited the physiological activity of Pma1p; and appeared to target Pma1p, with 50% inhibitory concentrations in the range of 0.5 to 2.5 microM. At sub-MICs (<5 microM), BM2 chemosensitized to fluconazole (FLC) S. cerevisiae strains functionally hyperexpressing fungal lanosterol 14alpha-demethylase and resistance-conferring transporters of azole drugs. BM2 chemosensitized to FLC some FLC-resistant clinical isolates of C. albicans and C. dubliniensis and chemosensitized to itraconazole clinical isolates of C. krusei that are intrinsically resistant to FLC. The growth-inhibitory concentrations of BM2 did not cause fungal cell permeabilization, significant hemolysis of red blood cells, or the death of cultured HEp-2 epithelial cells. BM2 represents a novel class of broad-spectrum, surface-active, Pma1p-targeting fungicides which increases the potencies of azole drugs and circumvents azole resistance.

Amino Acid Sequence↗

Emergency department waiting times for patients with cancer with febrile neutropenia: a pilot study.

PURPOSE/OBJECTIVES: To determine the time frame for evaluation and treatment of adult patients with febrile neutropenia in the emergency department (ED). DESIGN: Prospective, descriptive survey. SETTING: ED in a large, urban, academic health center. SAMPLE: 19 patients with febrile neutropenia during 23 ED visits in eight months. METHODS: Demographic and treatment variables and durations of time were recorded from ED and medical records. FINDINGS: Patients had fevers a mean of 21 hours (range = 1-72 hours) before seeking treatment. Median waiting time from ED admission to examination was 75 minutes, 210 minutes before antibiotics were given, and 5.5 hours to hospital admission. Patients with more comorbidities and more extensive cancer waited significantly longer than those at lower risk (p less than 0.002). CONCLUSIONS: Although the standard of care is to treat febrile neutropenia as an oncologic emergency, patients waited prolonged periods prior to receiving treatment. Studies are indicated to examine early intervention for febrile neutropenia and to determine whether early intervention improves clinical outcomes. IMPLICATIONS FOR NURSING: Nurses may repeat this study at other settings and with other populations of people with cancer. Other studies may provide evidence that clinical outcomes are dependent on rapid intervention for febrile neutropenia in the cancer population or evaluate the efficacy of education that oncology nurses deliver to people with cancer and febrile neutropenia.

Academic Medical Centers↗

A rat model of radiofrequency ablation of trigeminal innervation via a ventral approach with stereotaxic surgery.

Neurotrophic keratopathy (NK), a consequence of sensory denervation of the cornea, must be better understood in order to develop new approaches to therapy. The purpose of this study was to create a rat model for neurotrophic keratopathy by denervating the trigeminal nerve through a ventral approach with stereotaxic surgery. Stereotaxic coordinates were measured in 46 male Sprague Dawley rat cadavers for localization of V1. After further refining the coordinates in nine live animals, radiofrequency ablation was chosen as an effective method of disrupting the innervation to the cornea. Fifty-two live rats were treated with radiofrequency ablation to define the anatomical localization of the lesion by utilizing gross and histopathological studies. A gross lesion of the trigeminal nerve and/or ganglion was observed in 47 (90%) of the 52 animals. Histopathological studies revealed that all 52 animals had anatomical damage of the trigeminal innervation to the eye. Low mortality and little morbidity were observed in these animals. We have developed a rat model for neurotrophic keratopathy that is simple to produce, accurate in creating a lesion by utilizing stereotaxic techniques combined with radiofrequency ablation, and successful in decreasing morbidity and mortality.

Animals↗

Short- and long-term effects of handwashing with antimicrobial or plain soap in the community.

Little is known about effects of public use of antimicrobial handwashing soap. A double-blinded, randomized clinical trial of hands of primary caretakers in 238 inner city households was conducted in which effects of plain or antimicrobial (containing 0.2% triclosan) handwashing soap on bacterial counts of the hands were compared before and after a single wash and before and after handwashing following a year of product use. The randomly assigned product was provided without cost to each household during monthly home visits, and compliance with product use was monitored. Households were contacted by telephone weekly and with a home visit monthly for 11 months. Hand cultures were obtained before and after handwashing at baseline and after 11 months, using a modified glove juice technique. Overall, there were no significant differences in pre-to-post handwashing counts at baseline (p = 0.41), but by the end of one year, post-wash counts were significantly lower than pre-wash (p = 0.000) for those using either antimicrobial or plain soap. There were no significant differences in mean log counts either before or after handwashing between those using the antimicrobial or plain soap at baseline or after a year of use (all p values > 0.28). For the group using antimicrobial soap, higher counts were observed post-handwashing in 31.3% of paired samples at baseline and 26.7% after one year (p = 0.03). A single handwash had minimal effect on quantity of hand flora, but there were significant effects over time, regardless of whether antimicrobial or plain soap was used. In the absence of more definitive evidence, the risk-benefit ratio argues in favor of targeted rather than ubiquitous, general household use of antimicrobial soap.

Anti-Infective Agents, Local↗

Piloting web-based NAMCS data collection for nurse-managed centers.

Research consistently has shown that Nurse Practitioners (NPs) provide health care equivalent to that of physicians, and especially excel in patient education and case management, essential interventions to promote self-care in chronically ill ambulatory patients. Yet large-scale national studies have not been done. Nurse-managed centers are not included in the sampling frame of the National Ambulatory Medical Care Survey (NAMCS) and only 2.1% of the 2000 sample was from patient encounters with NPs.1 The aims of this pilot study were to create a web-based format for the NAMCS; to expand it by adding selected nursing diagnoses, interventions, and outcomes; and to pilot-test it with 300 patient encounters in 5 nurse-managed centers.

Ambulatory Care Facilities↗

Work stress in aging police officers.

Data are sparse regarding the impact of psychosocial work stress on the health and well-being of aging workers, even for employees working in high-stress occupations, such as law enforcement. To improve our understanding of this issue in older workers, we assessed and characterized work stress, coping strategies, and stress-related health outcomes in a sample of police officers aged 50 years and older (n = 105). The most important risk factors associated with officers' perceived work stress were maladaptive coping behaviors (e.g., excessive drinking or problem gambling) (odds ratio [OR], 4.95; 95% confidence interval [CI], 2.11 to 11.6) and exposure to critical incidents (e.g., shootings) (OR, 3.84; 95% CI, 1.71 to 8.65). In turn, perceived work stress was significantly associated with anxiety (OR, 6.84; 95% CI, 2.81 to 16.65), depression (OR, 9.27; 95% CI, 3.81 to 22.54), somatization (OR, 5.74; 95% CI, 2.47 to 13.33), posttraumatic stress symptoms (OR, 2.89; 95% CI, 1.29 to 6.47), symptoms of "burnout" (OR, 5.93; 95% CI, 2.54 to 13.86), chronic back pain (OR, = 3.55; 95% CI, 1.57 to 8.06), alcohol abuse (OR, 3.24; 95% CI, 1.45 to 7.22), and inappropriately aggressive behavior (OR, 4.00; 95% CI, 1.34 to 11.88). These data suggest that older workers in high-stress jobs may be at increased risk for work stress-related health problems, especially if they rely on risky health behaviors to cope with stress. Given the size of the rapidly aging US workforce and the likelihood that many are employed in high-stress jobs, interventions are urgently needed to address this emerging public health issue.

Adaptation, Psychological↗