Developing the reflective teacher

The conceptual issues and research findings surrounding the meaning and use of reflection are examined in this paper and serve as a foundation for discussing significant assumptions and beliefs regarding the use of reflection in nursing education. The strengths and limitations of reflection are discussed. The paper links current knowledge about reflection to the development of reflective thinking and its use by nurse educators and suggests strategies to enhance this development.     

Leukocytes in a Plasmodium falciparum-infected blood meal reduce transmission of malaria to Anopheles mosquitoes

Mosquitoes are infected with Plasmodium falciparum by taking a blood meal from a gametocyte carrier. Since a mosquito takes a volume of 1 to 2 microl, a blood meal may contain 1 x 10(4) to 3 x 10(4) leukocytes (WBC). The majority of WBC are composed of neutrophils which may phagocytose and kill developing gametes inside the mosquito midgut. Phagocytosis was measured in vitro by a luminol-dependent chemiluminescence (CL) assay. In the presence of P. falciparum gametes, sera from areas of endemicity had an increased CL response compared to controls. In mosquito membrane feeding experiments some such sera showed a transmission reduction which was related to the presence of viable WBC. The results of this study suggest that phagocytosis of opsonized gametes inside the mosquito midgut occurs and can contribute to a reduction in the transmission of P. falciparum parasites.     

A Monte Carlo study of the inferential properties of three methods of shape comparison

Three inferential morphometric methods, Euclidean distance matrix analysis (EDMA), Bookstein's edge-matching method (EMM), and the Procrustes method, were applied to facial landmark data. A Monte Carlo simulation was conducted with three sample sizes, ranging from n = 10 to 50, to assess type I error rates and the power of the tests to detect group differences for two- and three-dimensional representations of forms. Type I error rates for EMM were at or below nominal levels in both two and three dimensions. Procrustes in 2D and EDMA in 2D and 3D produced inflated type I error rates in all conditions, but approached acceptable levels with moderate cell sizes. Procrustes maintained error rates below the nominal levels in 2D. The power of EMM was high compared with the other methods in both 2D and 3D, but, conflicting EMM decisions were provided depending on which pair (2D) or triad (3D) of landmarks were selected as reference points. EDMA and Procrustes were more powerful in 2D data than for 3D data. Interpretation of these results must take into account that the data used in this simulation were selected because they represent real data that might have been collected during a study or experiment. These data had characteristics which violated assumptions central to the methods here with unequal variances about landmarks, correlated errors, and correlated landmark locations; therefore these results may not generalize to all conditions, such as cases with no violations of assumptions. This simulation demonstrates, however, limitations of each procedure that should be considered when making inferences about shape comparisons.     

Primary care physicians' medical decision making for late-life depression

OBJECTIVE: To describe primary care physicians' clinical decision making regarding late-life depression. DESIGN: Longitudinal collection of data regarding physicians' clinical assessments and the volume and content of patients' ambulatory visits as part of a randomized clinical trial of a physician-targeted intervention to improve the treatment of late-life depression. SETTING: Academic primary care group practice. PATIENTS/PARTICIPANTS: One-hundred and eleven primary care physicians who completed a structured questionnaire to describe their clinical assessments immediately following their evaluations of 222 elderly patients who had reported symptoms of depression on screening questionnaires. INTERVENTIONS: Intervention physicians were provided with their patient's score on the Hamilton Depression rating scale (HAM-D) and patient-specific treatment recommendations prior to completing the questionnaire regarding their clinical assessment. MAIN RESULTS: Those physicians not provided HAM-D scores were just as likely to rate their patients as depressed, as determined by specific query of these physicians regarding their clinical assessments. A physician's clinical rating of likely depression did not consistently result in the formulation of treatment intentions or actions. Treatment intentions and actions were facilitated by provision of treatment algorithms, but treatment was received by fewer than half of the patients whom physicians intended to treat. Barriers to treatment appear to include both physician and patient doubts about treatment benefits. CONCLUSIONS: Lack of recognition of depressive symptoms did not appear to be the primary barrier to treatment. Recognition of symptoms and access to treatment algorithms did not consistently result in progression to subsequent stages in treatment decision making. More research is needed to determine how patients and physicians weigh the potential risks and benefits of treatment and how accurately they make these judgments.     

Mitogenic and antiadipogenic properties of human growth hormone in differentiating human adipocyte precursor cells in primary culture

OBJECTIVE: To analyze cytomorphologic characteristics of hepatoblastoma (HB) and evaluate the feasibility of recognizing its histologic subtypes in smears. STUDY DESIGN: Fine needle aspirates from 14 primary and 1 metastatic HB were reexamined. The diagnosis of HB was confirmed by tissue examination (10 cases) and by clinical and laboratory findings alone (5 cases). RESULTS: In 12 samples, neoplastic cells resembled immature hepatocytes but were smaller and had a higher nuclear/cytoplasmic ratio. In nine of these smears the cells were rather uniform, while the other three presented with moderate pleomorphism. The cells were arranged in three-dimensional clusters, loose sheets, cords, rosettelike structures and occasional pseudopapillae and were dispersed. CONCLUSION: With knowledge of the cellular features and architectural patterns of HB, a reliable diagnosis could be obtained in 12/15 cases without the use of special techniques. In the remaining three aspirates the tumor cell population partly or entirely differed from normal hepatocytes, requiring ancillary techniques for proper diagnosis. On reexamination of the 10 cases with tissue diagnoses, 4/6 mixed HBs could be correctly subtyped, whereas the distinction between embryonal and fetal cells in four cases of epithelial HB seemed questionable.     

Ambulatory--not office--blood pressures decline during hormone replacement therapy in healthy postmenopausal women

Hormone replacement therapy (HRT, estrogen plus progestagen) in postmenopausal women has beneficial effects on the cardiovascular system. However, effects on blood pressure, determined with office measurements, remain controversial. We studied the effects of HRT in 29 healthy normotensive postmenopausal women (mean age 52.3 [3.8] years, median duration of amenorrhea 34.5 months), using ambulatory blood pressure monitoring at baseline and at 3 and 12 months of follow-up. Women were randomized to two groups: an HRT group (N = 14), treated with 1 mg 17beta-estradiol once daily and 5 or 10 mg dydrogesterone once daily during the third and fourth week of every 4 weeks; and a control group (C-group, N = 15), which did not receive therapy. Blood pressures did not differ between the groups at baseline (HRT group 117.1 (9.2)/74.4 (6.6) mm Hg, C-group 113.8 (11.2)/71.3 (7.4) mm Hg). During the follow-up period, changes from baseline of office blood pressures did not differ significantly between the groups. However, changes (95% CI) of mean 24-h blood pressures differed significantly between the two groups after 1 year of follow-up: a decrease of blood pressures was observed in the HRT group (delta systolic/delta diastolic = -5.54 [-8.86 to -2.21]/-4.23 [-6.66 to -1.80] mm Hg), whereas an increase was found in the C-group (+3.33 [-0.69 to +7.35]/+1.67 [-1.75 to +5.09] mm Hg; P [HRT v control group] = .001/.005). We conclude that HRT may have blood pressure lowering properties in healthy, normotensive postmenopausal women.     

Risk factors for ectopic pregnancy: a meta-analysis

OBJECTIVE: To review current knowledge on the risk of ectopic pregnancy (EP), with the exception of contraceptive methods. DESIGN: Meta-analysis. SETTING: Case control and cohort studies published between 1978 and 1994 in English, French, German, or Dutch, retrieved by Medline search, crossover search from the papers obtained, and hand-search on recent medical journals. PATIENTS: A total number of 6,718 cases of EP in 27 case control studies and 13,049 exposed women in 9 cohort studies. MAIN OUTCOME MEASURES: Detected studies were tested for homogeneity. If homogeneity was not rejected, Mantel-Haenszel common odds ratios (OR) and 95% confidence intervals were calculated. RESULTS: Previous EP, previous tubal surgery, documented tubal pathology, and in utero diethylstilbestrol (DES) exposure were found to be associated strongly with the occurrence of EP. Previous genital infections (pelvic inflammatory disease [PID], chlamydia, gonorrhoea), infertility, and a lifetime number of sexual partners > 1 were associated with a mildly increased risk. For gonorrhoea, PID, previous EP, previous tubal surgery, and smoking, a higher common OR was calculated when using pregnant controls compared with using nonpregnant controls. CONCLUSIONS: The strong risk in women with a previous EP, previous tubal surgery, documented tubal pathology, or in utero DES exposure justifies the exploration of a screening policy for EP among these women. If a risk factor reduces fertility chances, the OR detected when using pregnant controls is higher than the OR calculated using nonpregnant controls.     

Quality of patient care in the Medicare End-Stage Renal Disease Program: the basis and implementation of the 1994-1997 End-Stage Renal Disease Health Care Quality Improvement Program

In a population-based prospective study of epileptic seizures in adult s aged > 17 years, we identified 563 patients with possible seizures in a period of 34 months. Seizures were unprovoked in 160 patients, an incidence of 56 in 100,000 person-years. There was no difference in incidence between sexes. Age-specific incidences of unprovoked seizures increased sharply in men from age 60 years and in women from age 70 years. The incidence of unprovoked seizures in those aged > 65 years was 139 (men 166, women 116). The cumulative incidence of unprovoked seizures between the ages of 17 and 84 years was 4.6%. The proportion with an identified presumptive cause for unprovoked seizures increased with advancing age. A presumed etiology was identified in 77% of persons aged > 60 years. Stroke was the most common etiology, detected in 30% (incidence 16) and in 45% at ages > 60 years. Tumors were detected in 11% (incidence 6) and Alzheimer's disease was detected in 7% (incidence 4). Eighteen percent of patients were demented. Unprovoked seizures were partial in 68% of cases (incidence 38), and generalized in 16% (incidence 9). Another 13% of patients had generalized seizures, but seizure onset was not witnessed (incidence 7). In 16%, there was a delay of > 1 year from the first unprovoked seizure to initial diagnosis.     

Paired-spike interactions and synaptic efficacy of retinal inputs to the thalamus

In many neural systems studied in vitro, the timing of afferent impulses affects the strength of postsynaptic potentials. The influence of afferent timing on postsynaptic firing in vivo has received less attention. Here we study the importance of afferent spike timing in vivo by recording simultaneously from ganglion cells in the retina and their targets in the lateral geniculate nucleus of the thalamus. When two spikes from a single ganglion-cell axon arrive within 30 milliseconds of each other, the second spike is much more likely than the first to produce a geniculate spike, an effect we call paired-spike enhancement. Furthermore, simultaneous recordings from a ganglion cell and two thalamic targets indicate that paired-spike enhancement increases the frequency of synchronous thalamic activity. We propose that information encoded in the high firing rate of an individual retinal ganglion cell becomes distributed among several geniculate neurons that fire synchronously. Because synchronous geniculate action potentials are highly effective in driving cortical neurons, it is likely that information encoded by this strategy is transmitted to the next level of processing.