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PubMedDate not supplied

Dropouts from nursing education: path analysis of a national sample.

Path analysis was used to test a theoretical model of college nursing student dropouts. Multiple regression was used to assess the relative importance of the predictor variables. Students' self-reported reasons for dropping out were studied by contingency and correlational analyses to determine the relationship between these reasons and individual difference variables. Factor analysis was used to develop scales to measure the variables of locus of control, self-esteem, social integration, and institutional commitment. The sample of students was drawn from the National Longitudinal Study of the High School Class of 1972. Included in the sample were students entering two- and four-year nursing programs full-time in the fall of 1972. These two groups of students were found to be significantly different in measures of cognitive ability and in aspirations for further education. Approximately 27 percent of the two-year and 41 percent of the four-year students withdrew from their nursing programs during this study. Reasons for withdrawal most frequently cited by both groups related to losing interest in nursing and becoming interested in other fields of study. Educational aspirations had the strongest direct effect on persistence in nursing for two-year students; for four-year students, academic ability was the most powerful predictor of persistence.

Aptitude↗
PubMed1994

Identifying potential dropouts through school health records.

This study of the records of 255 ninth grade, inner-city Midwestern high school students shows that students who drop out of school are several times as likely to have incomplete health information in the school health record as students who stay in school. A cluster of five variables--vision screening, scoliosis screening, visits to the health office, age and attendance--were found to provide 85% or better accuracy in estimating actual drop-out rates. Missing or incomplete data in combination with attendance data thus become powerful predictors of potential dropouts.

Adolescent↗
PubMed1995

[Tuberculosis and patient compliance: proposition for a study methodology of patient dropouts].

Patient dropouts are one of the main concerns of tuberculosis programme in high prevalence countries. Perception of renunciation factors are generally weak or/and feeble from the part of agents working within programmes, while there are some a priori and confusions. This work proposes the setting up of a malagasy study, after the adequate definition of some hypothesis, then the writing of a survey form. The aim is to draw remedial behaviours and to make physicians and paramedical working close to tubercular patients, aware of the importance of a good mutual comprehension.

Attitude to Health↗
PubMed2001

A comparison of different lysis buffers to assess allele dropout from single cells for preimplantation genetic diagnosis.

Single cell polymerase chain reaction (PCR) for preimplantation genetic diagnosis (PGD) requires high efficiency and accuracy. Allele dropout (ADO), the random amplification failure of one of the two parental alleles, remains the most significant problem in PCR-based PGD testing since it can result in serious misdiagnosis for compound heterozygous or autosomal dominant conditions. A number of different strategies (including the use of lysis buffers to break down the cell and make the DNA accessible) have been employed to combat ADO with varying degrees of success, yet there is still no consensus among PGD centres over which lysis buffer should be used (ESHRE PGD Consortium, 1999). To address this issue, PCR amplification of three genes (CFTR, LAMA3 and PKP1) at different chromosomal loci was investigated. Single lymphocytes from individuals heterozygous for mutations within each of the three genes were collected and lysed in either alkaline lysis buffer (ALB) or proteinase K/SDS lysis buffer (PK). PCR amplification efficiencies were comparable between alkaline lysis and proteinase K lysis for PCR products spanning each of the three mutated loci (DeltaF508 in CFTR 90% vs 88%; R650X in LAMA3 82% vs 78%; and Y71X in PKP1 91% vs 87%). While there was no appreciable difference between ADO rates between the two lysis buffers for the LAMA3 PCR product (25% vs 26%), there were significant differences in ADO rates between ALB and PK for the CFTR PCR product (0% vs 23%) and the PKP1 PCR product (8% vs 56%). Based on these results, we are currently using ALB in preference to PK/SDS buffer for the lysis of cells in clinical PGD.

Alleles↗
PubMed1996

Reduced allele dropout in single-cell analysis for preimplantation genetic diagnosis of cystic fibrosis.

BACKGROUND: For couples at risk of transmitting a known single-gene defect, preimplantation genetic diagnosis (PGD) allows the identification and transfer of only unaffected embryos following in vitro fertilisation (IVF), single-cell biopsy at about the eight-cell stage, and genetic analysis by PCR. This technique therefore avoids the risk of terminating an affected pregnancy diagnosed later in gestation. METHODS AND RESULTS: Using nested PCR, the delta F508 mutation causing cystic fibrosis can be detected in single cells and we previously reported successful PGD in a couple in whom both partners carry the delta F508 mutation. To date we have treated 12 couples in a total of 18 cycles. This resulted in five singleton births confirmed to be homozygous normal. Single blastomeres from disaggregated embryos which had not been transferred were analysed to confirm the original diagnosis and assess reliability in clinical practice. Amplification efficiency and accuracy were high, with blastomeres from embryos diagnosed as homozygous normal or affected. In a proportion of blastomeres from presumed carrier embryos, one of the parental alleles failed to amplify, apparently at random (allele dropout, ADO). A possible explanation is the relative inaccessibility of one of the target allele early in the PCR. To test this we have used single lymphocytes from delta F508 carriers and investigated the effects of various denaturation temperatures in the early cycles of amplification. CONCLUSIONS: Increasing the denaturation temperature reduced the rate of ADO without affecting amplification efficiency.

Alleles↗
PubMed1996

Allele dropout in sequential PCR and FISH analysis of single cells (cell recycling).

PURPOSE: Our purpose was to investigate the feasability of using sequential PCR and FISH analysis of single cells for preimplantation diagnosis. METHODS: Protocols for sequential PCR and FISH analysis of a single fibroblast (cell recycling) were optimized for six loci and the rates of allele specific dropout (ADO) were determined. RESULTS: Conditions that allow reliable genotyping of single cells in lysis buffer were not optimal for amplifying fibroblasts fixed to coverslips. After optimizing conditions, we observed a success rate of 85% for both analyses in sequential PCR-FISH experiments in single cells for the four loci studied. The individual success rates for each technique revealed a slightly higher rate for FISH (91-95%) than for PCR (85-87%) for single cells on coverslips. The presence of two hybridization signals in FISH experiments demonstrated that the failure to amplify both alleles from heterozygous cells on coverslips was due to true ADO, and not the loss of chromosomal material. The ADO rate observed on coverslips varied between 10 and 14%, which is significantly higher than that observed in solution, even after meticulous optimization. CONCLUSIONS: Sequential PCR and FISH analysis of single cells remains an attractive possibility. However, until the problem of the increased rate of ADO is resolved, cell recycling should be applied to clinical preimplantation genetic analysis.

Alleles↗
PubMed1990

Neuronal dropout is greater in hindlimb motor nuclei than in forelimb motor nuclei in aged rats.

The number of forelimb, ulnar (U) and hindlimb, medial gastrocnemius (MG) motoneurons labeled with retrograde axonal transport of horseradish peroxidase was examined in young and aged rats. No significant difference was found between the mean number of U motoneurons in young and aged rats, whereas the mean number of MG motoneurons was significantly lower in aged rats than in young rats. These results suggest that motoneuronal dropout is greater in hindlimb motor nuclei than in forelimb motor nuclei, which may contribute to differential changes in forelimb and hindlimb muscles with increasing age.

Aging↗
PubMed1998

Allele dropout in polar bodies and blastomeres.

PURPOSE: Because allele dropout (ADO) is frequently observed in single-cell polymerase chain reaction analysis, it is important to develop a method for efficient detection of ADO, in order to avoid possible misdiagnosis in preimplantation diagnosis. METHODS: We introduced a simultaneous amplification of mutant genes and linked polymorphic markers, such as a 4-bp repeat (GATT) at the 3' end of intron 6 in the cystic fibrosis (CF) gene and a short tandem repeat at the 5' end of the beta-globin gene. Three types of single heterozygous cells were studied for the amplification of both alleles, including 150 blastomeres, 1615 fibroblasts, and 170 first polar bodies, obtained from patients at risk for having children with cystic fibrosis (delta F-508 mutation) or sickle cell disease. RESULTS: ADO rates of as high as 33.3% for delta F-508 mutation and 22.8% for beta-globin gene were observed in single blastomeres, compared to 7.1 and 7.7% in single fibroblasts and 5.9 and 9.6% in first polar bodies, respectively. The application of simultaneous amplification of the above linked polymorphic markers allowed detection of more than half of the cases of ADO in blastomeres (19.4% for cystic fibrosis and 12.3% for beta-globin gene) and almost all ADOs in polar bodies, particularly when the two-step sequential analysis of the first and second polar body was applied in preimplantation diagnosis of single gene disorders. CONCLUSIONS: Simultaneous amplification of linked polymorphic markers in single-cell DNA analysis of single-gene defects is an efficient method for avoiding the risk of misdiagnosis in preimplantation diagnosis.

Alleles↗
PubMed2003

Evaluation of quality of life in a clinical trial with nonrandom dropout: the effect of epoetin alfa in anemic cancer patients.

Quality of life (QOL) endpoints from a randomized, placebo-controlled trial of anemic cancer patients treated with nonplatinum-containing chemotherapy who received epoetin alfa or placebo were subjected to a sensitivity analysis. Three QOL instruments were used: the Functional Assessment of Cancer Therapy-Anemia (FACT-An), the Cancer Linear Analog Scale (CLAS), and the Medical Outcomes Study Short Form-36 (SF-36). The seven primary endpoints chosen a priori for analysis were: the Functional Assessment of Cancer Therapy-General (FACT-G) Total, FACT-An fatigue subscale, CLAS energy, CLAS daily activities, CLAS overall QOL, and the SF-36 physical and mental component summary scales. Lower QOL scores were reported for patients who discontinued early, suggesting a nonrandom dropout process. Significant correlations (ranging from 0.37 to 0.77) between individual rates of change and the time to early termination of therapy or death supported this conclusion. Estimates of within-treatment-arm QOL change over time are more conservative with the missing not at random (MNAR) assumption as compared with the more optimistic estimates with the assumption that missing QOL data are missing at random (MAR). However, the between-treatment-arm comparisons were consistent across analyses, demonstrating statistically significant differences in favor of the epoetin alfa arm for four of the seven outcome measures.

Aged↗
PubMed1996

Increasing the denaturation temperature during the first cycles of amplification reduces allele dropout from single cells for preimplantation genetic diagnosis.

Single cell polymerase chain reaction (PCR) for preimplantation genetic diagnosis (PGD) needs to be highly efficient and accurate. In some single cells from human embryos presumed to be heterozygous for the delta F508 deletion causing cystic fibrosis (CF), we recently observed random amplification failure of one of the two parental alleles following nested PCR. To investigate allele dropout (ADO), we have examined two different lysis protocols and the effect of altering the denaturation temperature in the primary PCR using single lymphocytes heterozygous for delta F508 or for two beta-thalassaemia mutations IVS 1 nt 1 (G/T) and 5 (G/C) using a nested PCR protocol to amplify the 5' region of the beta-globin gene. Amplification rates were high after lysis in either water or lysis buffer and at all denaturation temperatures studied (> or = 92%). With a typical denaturation temperature (93 degrees C), ADO was detected at both loci. When the denaturation temperature was lowered to 90 degrees C, however, ADO increased substantially and conversely by raising the denaturation temperature to 96 degrees C during the first 10 cycles ADO was reduced but not eliminated. ADO was also reduced with cells in lysis buffer. We suggest that ADO may be caused by a combination of inefficient denaturation and degradation of one of the genomic alleles in the first cycles of PCR. For autosomal recessive conditions in which both parents are carrying the same mutation, ADO would not cause serious misdiagnosis. For compound heterozygotes or autosomal dominant conditions, however, extensive testing of the amplification protocol with single heterozygous cells and individual calibration of each thermocycler for the effect of denaturation temperature on ADO is essential before clinical application.

Alleles↗
PubMed2005

[Dropout from tuberculosis treatment in Nicaragua: the results of a comparative study].

OBJECTIVE: To identify factors related to dropping out from tuberculosis treatment in health centers in the departments of Managua and Matagalpa, in Nicaragua. METHODS: This study matched cases and controls (1:1 ratio) by age and by municipality of treatment. The 251 cases were patients over 15 years of age who had dropped out of tuberculosis treatment, and the 251 controls were patients who had completed pharmacotherapy, during the period of January 1998 to December 2001. Data were obtained on demographic and socioeconomic characteristics, lifestyle habits, and treatment characteristics. The variables were chosen and grouped using a hierarchical theoretical model. Conditional logistic regression analysis was used to calculate odds ratios (ORs) with 95% confidence intervals (95% CIs). RESULTS: The risk factors for dropping out of tuberculosis drug treatment were: male gender (OR, 2.51; 95% CI, 1.63 to 3.94), an unstable living situation or being homeless (OR, 3.08; 95% CI, 1.57 to 6.49), changing residence during the treatment period (OR, 4.22; 95% CI, 2.06 to 9.93), consuming alcoholic beverages (OR, 5.25; 95% CI, 2.43 to 12.94), using illegal drugs (OR, 5.25; 95% CI, 2.43 to 12.94), difficulty in access to the health services (OR, 2.64; 95% CI, 1.39 to 5.29), and a negative opinion of the health care received (OR, 5.33; 95% CI, 1.52 to 28.56). CONCLUSIONS: It is essential for the health services in Nicaragua to develop measures to reduce the risk of dropout from treatment. In particular, it is important for the health sector to work with community groups that can support the health sector's activities.

Adolescent↗
PubMedDate not supplied

Allele-dropout using PCR-based diagnosis for the splicing mutation in intron-2 of the CYP21B-gene: successful amplification with a Taq/Pwo-polymerase mixture.

The splicing mutation in intron 2 (nucleotide 656) of the 21-hydroxylase gene (CYP21B) is the most common mutation causing congenital adrenal hyperplasia (CAH). Homozygosity for nt656G is associated with the classical phenotype of CAH. In several studies, a number of clinically asymptomatic relatives of CAH-patients were genotyped as nt656G homozygotes. We have proposed that the putative asymptomatic nt656G/G individuals are incorrectly typed due to dropout of one allele (in most cases nt656C) during PCR amplification. Here, we report the successful amplification of all alleles at nt656 with a Taq/Pwo DNA polymerase mixture in the primary PCR reaction. The results were independent from the type of polymerase used for sequencing reactions as the second step in mutation analysis.

Adrenal Hyperplasia, Congenital↗