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Biomedical subjects

Sarah Parker

Publications and source records attributed to Sarah Parker.

8 recordsLinked to original sources
PubMed2006

Nested polymerase chain reaction detection and duration of porcine circovirus type 2 in semen with sperm morphological analysis from naturally infected boars.

A nested polymerase chain reaction (nPCR) protocol was applied to porcine semen to demonstrate the porcine circovirus type 2 (PCV2) shedding patterns and duration in naturally infected boars. Sperm morphology analysis was performed on a subset of samples to determine if the presence of PCV2 DNA in semen was associated with reduced semen quality. Semen was collected serially from 43 boars representing 6 breeds, aged 33.9 to 149.3 weeks. Of the 903 semen samples collected, 30 samples (3.3%) were positive for PCV2 DNA by nPCR from 13 boars. Boars shedding PCV2 DNA in semen ranged between 35.9 and 71.0 weeks of age, and shedding occurred during a period of up to 27.3 weeks. A semen nPCR test was 2.6 times more likely to be positive when collected from pigs that were < or =52 weeks of age, and 3.0 times more likely to be positive when collected from pigs that were < or =26 weeks from time of entry into the stud main unit (generalized estimating equations: P = 0.02; 95% confidence interval [CI] of the odds ratio 1.2 to 5.5, and P = 0.01; 95% CI of the odds ratio 1.3 to 6.9, respectively). These results demonstrate a sporadic and long-term shedding pattern of PCV2 DNA in semen from naturally infected boars. PCV2 DNA in semen does not appear to have detrimental effects on sperm morphology; however, boar age and, possibly, breed may contribute to the persistence of PCV2-shedding in semen.

Animals↗
PubMed2003

Comparison of the diagnostic sensitivity of a commercially available culture kit and a diagnostic culture test using Diamond's media for diagnosing Tritrichomonas foetus in bulls.

A number of different culture media have been described for use in the diagnosis of Tritrichomonas foetus infection in bulls, and recently, a commercial culture kit has become available. The objective of this study was to compare the sensitivity of 2 culture-based diagnostic tests for T. foetus in bulls. One test used a commercial kit for transport and culture of the samples. The other test used a thioglycollate transport medium (TFTM) for transport and a modified Diamond's medium (MDM) for culture of the samples. Twenty-one bulls infected with T. foetus were sampled repeatedly. On each sampling day, samples collected from the left and right sides of the bull were tested with one of the 2 diagnostic tests being compared. The effect of the type of diagnostic test on the outcome of the test was evaluated with a chi-square test for the calculated odds ratio. Because repeated tests from the same bull cannot be considered independent measures, unadjusted chi-square tests were adjusted for the effect of clustering by bull. Samples tested using the commercial kit were 6.95 times as likely to be positive as samples tested with a diagnostic test using MDM (P < 0.001).

Animals↗
PubMed2003

Comparison of a modified digestion assay with trichinoscopy for the detection of Trichinella larvae in pork.

A pepsin-HCl digestion assay and two compressorium techniques (trichinoscopy) for the identification of swine muscle tissue containing low levels of Trichinella larvae were compared as part of the test validation process for quality assurance purposes. Compressoria read with a stereomicroscope detected more larvae (P < 0.0001, n = 57) and more tissues (P = 0.0047, n = 57) than did compressoria read with a projection microscope (trichinoscope). The digestion assay evaluated was 3.2 times as likely as the best compressorium technique to identify a positive tissue when these procedures were used to test 1 g of infected muscle (P < 0.001; 95% confidence interval for the odds ratio, 2.0 to 5.4; n = 161 and n = 189, respectively). Detection by trichinoscopy improved as the number of larvae in tissues increased to > 2 larvae per g, but trichinoscopy was less sensitive than the digestion assay regardless of the tissue larval load. These data indicate that the quality controlled digestion assay used in this study is more sensitive than trichinoscopic techniques in the detection of tissues containing low levels of Trichinella larvae.

Animals↗
PubMed2003

Sample collection factors affect the sensitivity of the diagnostic test for Tritrichomonas foetus in bulls.

The current diagnostic test for Tritrichomonas foetus involves the culture of collected preputial or vaginal samples. In an earlier study, which evaluated sampling tools for use with bulls, it was observed that the sensitivity of the diagnostic test was higher for 2nd samples collected from the right side of the prepuce than it was for samples collected 1st from the left side. The study described in this paper was conducted to evaluate which of these factors was responsible for the effect on diagnostic sensitivity. Twenty-nine bulls infected with T. foetus were repeatedly sampled in a 2-factor cross-over design. Samples taken from the right side of the prepuce were 4 times as likely to be positive as samples taken from the left side (P = 0.03). Other factors did not have a significant effect on the outcome of the diagnostic test. Unexpected factors may affect the sensitivity of the diagnostic test for T. foetus.

Animals↗
PubMed2003

Diagnosis of trichomoniasis in 'virgin' bulls by culture and polymerase chain reaction.

The diagnostic test for Tritrichomonas foetus in bulls is microscopic examination of cultured preputial samples. Trichomonads other than T. foetus can be present in a preputial sample. Both a staining technique and a polymerase chain reaction assay were useful in differentiating between T. foetus and another trichomonad observed in samples from virgin bulls.

Animals↗
PubMed2002

Seeking help from the internet during adolescence.

OBJECTIVE: To assess the prevalence and demographic and psychological correlates of Internet use as a help-seeking resource for emotional problems in a community sample of adolescents. METHOD: A self-report survey was completed by 9th-through 12th-grade students ( = 519) enrolled in health courses in six New York State high schools in the fall/winter of 1999. The relationship between Internet help-seeking behavior and demographic characteristics, hopelessness, functional impairment, and use of various treatment services was examined. RESULTS: Nearly one fifth (18.2%) of the adolescents sought help on the Internet for emotional problems in the previous year. The proportions of males and females seeking help on the Internet did not significantly differ (15.6% and 20.8%, respectively). Internet help-seekers were significantly more likely than non-help-seekers to score above the clinical threshold on the Columbia Impairment Scale (34% versus 20.6%; chi(2)(1) = 7.4, <.01) or Beck Depression Inventory (16.1% versus 9.1%; chi(2)(1) = 3.8, <.05). These at-risk youths tended to combine Internet help-seeking with other sources of help, rather than substituting it for other resources. More than 20% of Internet help-seekers were dissatisfied with the help they received, and only 14% thought it had helped them very much. CONCLUSIONS: For the Internet to realize its potential as an effective resource for teenagers struggling with emotional problems, further development is needed.

Adolescent↗