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Biomedical subjects

C Hayden

Publications and source records attributed to C Hayden.

13 recordsLinked to original sources

Buccinator sandwich pushback: a new technique for treatment of secondary velopharyngeal incompetence.

OBJECTIVE: A small percentage of patients have inadequate velopharyngeal closure, or secondary velopharyngeal incompetence, following primary palatoplasty. Use of the buccinator musculomucosal flap has been described for primary palate repair with lengthening, but its use in secondary palate lengthening for the correction of insufficient velopharyngeal closure has not been described. This study presents the results of a series of patients who had correction of secondary velopharyngeal incompetence using bilateral buccinator musculomucosal flaps used as a sandwich. PATIENTS: In this prospective study between 1995 and 1998, a group of 16 patients with insufficient velopharyngeal closure as determined by speech assessment and videoradiography were selected. Nasopharyngoscopy was carried out in addition in a number of cases. Case selection was a result of these investigations and clinical examination in which the major factor in velopharyngeal insufficiency was determined to be short palatal length. DESIGN: The patients underwent palate lengthening using bilateral buccinator musculomucosal flaps as a sandwich. All patients were assessed 6 months postoperatively. The operative technique, postoperative course, and recorded postoperative complications including partial/total flap necrosis and residual velopharyngeal insufficiency were evaluated. Preoperative and postoperative speech samples were rated by an independent speech therapist. RESULTS: Ninety-three percent (15 of 16) had a significant improvement in velopharyngeal insufficiency, and 14 patients had no hypernasality postoperatively. Both cases of persistent mild hypernasality had had a recognized postoperative complication. CONCLUSION: The sandwich pushback technique for the correction of persistent velopharyngeal incompetence was successful in achieving good speech results.

Adolescent↗

DNA strand breaks, oxidative damage, and 1-OH pyrene in roofers with coal-tar pitch dust and/or asphalt fume exposure.

OBJECTIVE: To determine the potential for asphalt fume exposure to increase DNA damage, we conducted a cross-sectional study of roofers involved in the application of roofing asphalt. METHODS: DNA strand breaks and the ratio of 8-hydroxydeoxyguanosine (8-OHdG) to 2-deoxyguanosine (dG) were measured in peripheral blood leukocytes of roofers. In addition, urinary excretion of 8-OHdG and 8-epi-prostaglandin F2alpha (8-epi-PGF) was also measured. The study population consisted of 26 roofers exposed to roofing asphalt and 15 construction workers not exposed to asphalt during the past 5 years. A subset of asphalt roofers (n = 19) was exposed to coal-tar pitch dust (coal tar) during removal of existing roofs prior to applying hot asphalt. Personal air monitoring was performed for one work-week to measure exposure to total particulates, benzene-soluble fraction of total particulates, and polycyclic aromatic compounds (PACs). Urinary 1-OH-pyrene levels were measured as an internal biomarker of PAC exposure. RESULTS: Full-shift breathing zone measurements for total particulates, benzene-solubles and PACs were significantly higher for coal-tar exposed workers than for roofers not exposed to coal tar. Similarly, urinary 1-OH-pyrene levels were higher in coal-tar exposed roofers than roofers not exposed to coal tar. Total particulates or benzene-soluble fractions were not associated with urinary 1-OH-pyrene, but PAC exposure was highly correlated with urinary 1-OH-pyrene. When stratified by 1-OH-pyrene excretion, DNA strand breaks increased in a dose-dependent manner, and leukocyte 8-OHdG/dG decreased in a dose-dependent manner. Significant changes in DNA damage appeared to be linked to PACs from coal-tar exposure, although asphalt fume alone was associated with a small but significant increase in urinary 1-OH-pyrene and DNA strand breaks. CONCLUSIONS: Results are consistent with previous reports that asphalt or coal-tar exposure can cause DNA damage. Urinary 8-epi-PGF remained relatively constant during the week for virtually all subjects, regardless of exposure indicating that neither asphalt nor coal-tar exposure induces an overt oxidative stress. A small, but statistically significant increase in 8OHdG was evident in end-of-week urine samples compared with start-of-week urine samples in roofers exposed to coal-tar. The increase in urinary 8OHdG coupled with the decrease in leukocyte 8-OHdG/dG, suggests that coal-tar exposure induces protective or repair mechanisms that result in reduced levels of steady-state oxidative-DNA damage.

8-Hydroxy-2'-Deoxyguanosine↗

Impact of a formulary change in proton pump inhibitors on health care costs and patients' symptoms.

Patients may fail to successfully undergo a switch in therapy associated with a formulary change. The aim of this study was to measure health care costs and outcomes among patients who failed a formulary change in proton pump inhibitors in a VA medical center. Patients who failed a switch from omeprazole to lansoprazole (N = 51) were matched with patients who were successfully switched (N = 51). Health care utilization data was gathered from VA electronic databases and medical records for six months before and after the switch and, for failure patients, during the lansoprazole trial period. Statistical comparisons between failure and success patients were performed on changes in health care costs between these time periods. Health outcome data for the lansoprazole trial period and subsequent omeprazole reinstatement period were obtained through a telephone questionnaire of failure patients. Changes in total health care utilization costs did not differ significantly between failure and success groups for any of the time periods. Failure patients had significantly poorer health outcomes during their lansoprazole trial periods with significantly greater severity of heartburn and severity and frequency of acid regurgitation (P < 0.001). In conclusion, the formulary change had a negative impact upon health outcomes among failure patients but did not significantly affect their health care utilization costs. Identification of failure patients early in their lansoprazole trial periods could improved their health outcomes and satisfaction with medical care.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Cervical cytology history in Irish doctors and midwives.

In Ireland we do not have a national cervical screening programme. It is hoped that such a service will soon be implemented and a pilot programme is currently underway. In our department there was a perception that many women working in the area of women's health had a "laissez-faire" attitude towards their own cervical cytology. This prompted us to perform an anonymous survey of a sample of Irish gynaecologists, general practitioners and midwives in advance of a national cervical screening programme. Overall, 80% of the questionnaires were returned completed--72% from gynaecologists, 68% from GPs and 100% from midwives. 60% of those who returned completed questionnaires were "up-to-date", 21% were "late" and 19% had never had a cervical smear.

Adult↗

Jabberwocky.

Explore the source record for details and available documents.

Humans↗

"A satellite primer on tuberculosis:" a collaboration in distance education.

"A Satellite Primer on Tuberculosis" was offered as a distance-based certificate course on tuberculosis (TB) fundamentals to a national audience of over 5,000 individuals. The course was a collaborative effort of a school of public health, a state health department, and the Centers for Disease Control and Prevention. Instruction was provided through print-based self-study modules that were complemented by live, interactive satellite conferences. Course completers, over 70 percent of whom were nurses and employees of public health departments, scored significantly higher on a course posttest than on a pretest, and the vast majority felt the course provided valuable training.

Curriculum↗

Mutation screening of interferon-gamma (IFNgamma) as a candidate gene for asthma.

BACKGROUND: Reduced levels of interferon gamma (IFNgamma) mRNA and protein have been detected in the bronchoalveolar lavage fluid of atopic asthmatics. IFNgamma is secreted by TH1 cells while IL-4 and IL-5 are secreted by TH2 cells and an imbalance in the TH1/TH2 response may be responsible for atopic asthma. The gene for IFNgamma is located on chromosome 12; a region of the genome which has been shown in linkage studies to be associated with asthma. OBJECTIVE: To determine if there are any mutations present in the coding exons and 5' flanking region of the IFNgamma gene in atopic asthmatic subjects compared with controls to explain the lower levels of this cytokine as an inherited, rather than acquired, factor in the asthmatic subjects. METHODS: The four exons and 5' flanking region of the IFNgamma gene were amplified by polymerase chain reaction (PCR) from genomic DNA of 265 individuals from a Western Australian and a Venezuelan population. The PCR products were examined by single strand conformational polymorphism and heteroduplex analyses to see if there were any changes in the DNA migration patterns which would suggest the presence of a sequence variation. RESULTS: The four exons and the 5' flanking region of the IFNgamma gene were amplified from 265 individuals from two populations. Single strand conformational polymorphism and heteroduplex analyses did not reveal any mutations in the regions examined. CONCLUSION: The gene for IFNgamma appears to be highly conserved as no sequence variations were detected in 265 individuals. These results suggest that mutations of the IFNgamma gene are unlikely to be a significant cause of an inherited asthma diathesis.

Adolescent↗

Proliferative indices and oncoprotein expression in benign and malignant breast biopsies.

BACKGROUND: Prognostic factors are used routinely in the management of breast cancer. However, their potential for identifying precursor malignant lesions has not been assessed. METHODS: We have examined 285 breast biopsy specimens (140 benign, 145 malignant) for DNA ploidy, S-phase fraction, Ki-67 nuclear antigen proliferative indices, and HER-2/neu and epidermal growth factor receptor oncoproteins. RESULTS: When proliferative indices were compared between the benign and malignant groups, differences were noted for DNA ploidy, S-phase fraction, and cell cycling index (p < 0.0005). When the benign nonproliferative specimens were compared with the atypical/proliferative benign specimens, proliferative indices failed to show any differences. When the specific subset of proliferative/atypical benign breast tissue was compared with the malignant specimens, DNA index, S-phase fraction, and cell cycling index showed significant differences. The mean for epidermal growth factor receptor was greater in the non-proliferative group but not statistically significant (p < 0.1). HER-2/neu oncoprotein failed to show any differences between the benign and malignant groups. Within the atypical benign group, Ki-67 correlated strongly with S-phase fraction and HER-2/neu (p < 0.01). CONCLUSIONS: We have demonstrated that proliferative indices can differentiate between benign and malignant breast tissues but not among specific subgroups. In addition, epidermal growth factor may differentiate between nonproliferative and proliferative/atypical benign biopsy results. Oncoprotein determination, ploidy, and DNA proliferative indices may be useful in defining malignant and benign breast disease but are not useful in distinguishing between benign and malignant breast disease with an increased likelihood for malignant transformation.

Analysis of Variance↗

Secretion of phospholipase C by Pseudomonas aeruginosa.

The conditions necessary for the secretion of phospholipase C (phosphatidylcholine cholinephosphohydrolase) by Pseudomonas aeruginosa were studied. Enzyme secretion by washed cell suspensions required a carbon source and ammonium, potassium, and calcium ions. The calcium requirement could be substituted by magnesium and strontium but not by copper, manganese, cobalt, or zinc. During growth in liquid medium, cells secreted phospholipase C during late logarithmic and early stationary phases. Secretion was repressed by the addition of inorganic phosphate but not by organic phosphates, glucose, or sodium succinate. Studies with tetracycline indicated that de novo protein synthesis was necessary for the secretion of phospholipase C and that the exoenzyme was not released from a preformed periplasmic pool. Similarly, extraction of actively secreting cells with 0.2 M MgCl2 at pH 8.4 solubilized large quantities of the periplasmic enzyme alkaline phosphatase but insignificant amounts of phospholipase C. Bacteria continued to secrete enzyme for nearly 45 min after the addition of inorganic phosphate or rifampin.

Carbon↗