Factors predictive of adolescents' intentions to use birth control pills, condoms, and birth control pills in combination with condoms.

Using the Theory of Planned Behaviour (Ajzen, 1988) as a conceptual framework, 705 secondary school students were surveyed to identify their intentions to use birth control pills, condoms, and birth control pills in combination with condoms. Hierarchical multiple regression revealed that the theory explained between 23.5% and 45.8% of the variance in intentions. Variables external to the model such as past use, age, and ethnicity exhibited some independent effects. Attitudes were consistently predictive of intentions to use condoms, pills, and condoms in combination with pills for both male and female students. However, there were differences by gender in the degree to which subjective norms and perceived behavioural control predicted intentions. The findings suggest that programs should focus on: creation of positive attitudes regarding birth control pills and condoms; targeting important social influences, particularly regarding males' use of condoms; and developing strategies to increase students' control over the use of condoms.

A pilot study to compare the effectiveness of preceptored and nonpreceptored models of clinical education in promoting baccalaureate students' competence in public health nursing.

Preceptor models in nursing have only recently begun to be evaluated, and the published results of their effectiveness are inconsistent and inconclusive. To date, the preceptor evaluation studies found in nursing literature refer to clinical practice in hospitals. This descriptive correlational pilot study (N = 25) compared the effectiveness of preceptored and nonpreceptored models of clinical nursing education in promoting baccalaureate nursing students' competence in public health nursing. The study also compared the learning experiences of students in the two models. Findings from the study revealed that although students in both models reported similar numbers of learning experiences, there were some differences in the types of experiences obtained. Students in both models demonstrated significant gains in perceptions of clinical competence during the 12-week experience. However, there was no significant difference found between the two groups in gain in perceived clinical competence.

Phosphomonoester is associated with proliferation in human breast cancer: a 31P MRS study.

Phospholipid metabolism of human breast cancer was studied by 31P magnetic resonance spectroscopy (MRS). In vivo localised 31P MR spectra were obtained from the tumour alone using phase modulated rotating frame imaging. For 31 tumours, median (range) phosphomonoester (PME) to ATP ratio was 1.48 (0.57-3.78) and phosphodiester (PDE) to ATP ratio was 1.65 (0.44-3.89). DNA index and S phase fraction (SPF) were measured by flow cytometry of paraffin embedded tissue. Twelve (39%) tumours were diploid and 19 aneuploid. Median (range) SPF for 29 assessable tumours was 5.3% (0.6-28%), with significantly greater median SPF for aneuploid tumours (9.3%) than diploid (3.8%, P = 0.007). There was a significant association between PME/ATP and SPF (P = 0.03) due to a significant correlation for aneuploid tumours (P = 0.01). High resolution 31P MRS of extracts from 18 tumours (including seven studied in vivo) demonstrated that the PME peak consists predominantly of phosphoethanolamine (PE) with a smaller contribution from phosphocholine (PC) (median (range) PE/PC: 3.02 (1.13-5.09)). Changes in PME/ATP were observed for two tumours where tamoxifen stablized disease and may be consistent with the cytostatic effects of this drug.

19F and 1H magnetic resonance strategies for metabolic studies on fluorinated xenobiotics: application to flurbiprofen [2-(2-fluoro-4-biphenylyl)propionic acid].

Strategies for the use of 1H and 19F nuclear magnetic resonance (NMR) spectroscopy as an aid to the study of the metabolic fate of fluorinated drugs are discussed with reference to the application of these methods to flurbiprofen metabolism in man. 1H and 19F NMR analysis of untreated urine enabled the detection of two major and eight minor metabolites of the drug. The two major metabolites were identified using a combination of NMR spectroscopy, solid-phase extraction chromatography with 19F and 1H NMR detection and chemical hydrolysis to a flurbiprofen glucuronide and the glucuronide of the 4-hydroxy metabolite. 1H-19F 2D shift correlated spectroscopy and spin-echo difference experiments are discussed in relation to their use in the structural identification of drug metabolites.

Determination of hydralazine in human whole blood.

The time required for the separation of plasma from the cellular components of blood can permit the in vitro loss of hydralazine. Thus, a high-performance liquid chromatographic (HPLC) procedure for the measurement of hydralazine in blood has been developed. 4-Methylhydralazine was used as an internal standard. The addition of p-anisaldehyde led to the formation of the p-anisaldehyde hydrazones of hydralazine and the internal standard. HPLC on a reverse-phase cyano column provided an analytical procedure in which the average relative standard deviation over the concentration range of 1-160 ng/ml was 8.3%. Hydralazine pyruvic acid hydrazone, a known circulating metabolite of hydralazine, yielded only 0.05 mole % hydralazine when submitted to this assay procedure.