A journey to becoming: the student nurse in transition.

The study reported in this paper explored the nature of the transition experienced by student nurses in their journey to becoming qualified nurses. In keeping with the developing relationship between the disciplines of anthropology and nursing, the methodology of choice was ethnography. Data were collected by open-ended questionnaires and interviews with key informants from one English College of Nursing undertaking Diploma level Project 2000 Adult Branch Studies. Thematic analysis of the data revealed an ill-defined transition for the student nurse and this lack of clarity was being perpetuated for many by their dual role as both student nurse and worker. This was also creating a potential role conflict and a blurring of the boundaries between professional nursing and skilled health care work. The data also revealed two 'in limbo' states, a ritualized transition phase, and that the rationale for 'learning to become a nurse' retains the idealized and vocational imagery of nursing as helping and caring for sick people.

Peripubertal ontogeny and estrogen stimulation of cholecystokinin and preproenkephalin mRNA in the rat hypothalamus and limbic system.

The neuropeptide cholecystokinin (CCK) is expressed in limbic system and hypothalamic nuclei that form a circuit that regulates the display of the female rodent reproductive behavior, lordosis. CCK mRNA and peptide levels fluctuate across the estrous cycle and have been shown to be modulated by estrogen exposure. The objective of these experiments was to examine the expression of CCK mRNA during postnatal development of this limbic-hypothalamic, lordosis regulating circuit, and to determine the age at which CCK mRNA expression becomes responsive to estrogen stimulation, by using quantitative in situ hybridization histochemistry. CCK mRNA levels were below the level of detectability within the circuit during the postnatal period, but increased during the peripubertal period. Rats were injected with either estradiol benzoate (EB), EB and progesterone, progesterone, or oil, and were killed 48 hours later on postnatal day (PND) 15, 20, and 25. Alternate brain sections were processed for CCK and preproenkephalin (PPE) mRNA in situ hybridization histochemistry. EB treatment induced CCK mRNA expression in the central portion of the medial preoptic nucleus and posterodorsal medial amygdala at PND 20 and 25, respectively. However, EB treatment increased PPE mRNA levels within the nuclei of the circuit at all ages examined. Progesterone had neither an independent nor additive effect on the EB induction of these neuropeptide messages. The estrogenic induction of CCK mRNA appears to be dependent on estrogen sensitive pathways of neurotransmission, or components of second messenger pathways which regulate CCK mRNA expression in the adult limbic-hypothalamic lordosis regulating circuit, which are not functional before PND 18-25.

Interaction of thyroxine and estrogen on the expression of estrogen receptor alpha, cholecystokinin, and preproenkephalin messenger ribonucleic acid in the limbic-hypothalamic circuit.

To study thyroid hormone and estrogen interactions in the central nervous system (CNS), the expression of estrogen sensitive genes was examined within the limbic-hypothalamic circuit. Estrogen up-regulates the expression of reproductively relevant neuropeptide messenger RNAs (mRNAs) encoding cholecystokinin (CCK) and enkephalin, peptides that stimulate lordosis. Estrogen down-regulates the expression of the estrogen receptor alpha (ER alpha) mRNA in the nuclei of the circuit. We examined the possibility that thyroid hormone treatment would block the estrogen modulation of these messages. Estradiol benzoate (EB), EB + thyroxine (T4), T4, or oil were administered to ovariectomized, adult female rats for 10 days. Isotopic in situ hybridization histochemistry revealed that within the limbic-hypothalamic nuclei, levels of CCK and preproenkephalin (PPE) mRNA levels were significantly higher in EB and EB + T4-treated animals compared with T4 or oil-treated animals. ER alpha mRNA levels were low in EB treated animals, elevated in T4 or oil-treated animals and further elevated in EB + T4-treated animals. In summary, T4 treatment had neither an independent nor an antagonistic effect on estrogen induced expression of CCK or PPE mRNA in the circuit. However, T4 did prevent the normal estrogenic decrease of ER alpha mRNA levels in the nuclei of the limbic-hypothalamic circuit.

Alternatives to traditional illness models. Interview by Cheryl Slagle King.

The Center for Human Caring at the School of Nursing, University of Colorado Health Sciences Center embraces complementary care modalities. The author interviews Karen Holland, Executive Director for the Center.

Estrogen modulation of opioid and cholecystokinin systems in the limbic-hypothalamic circuit.

The display of lordosis behavior has been correlated with the estrogen-induced expression of cholecystokinin (CCK) and enkephalin within the limbic-hypothalamic circuit. These neuropeptides have opposing effects on lordosis; for example, in the medial preoptic nucleus, CCK facilitates and opiates inhibit lordosis. Antisense oligodeoxynucleotide blockade of receptor expression indicated that CCK modulates lordosis in the medial preoptic nucleus through the CCK(A)-receptor. Sequence-specific antibodies directed against delta- and mu-opiate receptor proteins labeled fibers in the medial preoptic nucleus. Estrogen treatment of ovariectomized rats or etorphine (a nonselective opiate agonist) treatment altered the appearance of the immunoreactivity from a diffuse pattern to one of distinctly stained mu-opiate receptor immunoreactive cells and varicose fibers in the medial preoptic nucleus. Such a pattern of staining reflects an internalization of mu-opiate receptors following agonist stimulation. This type of internalization has been used as an indication of synaptic activity. The distribution of receptor internalization surrounds the distribution of CCK cells in the medial preoptic nucleus, suggesting that endogenous opioid peptides may modulate estrogen-induced CCK mRNA expression. Interestingly, nonselective and delta-opiate receptor selective antagonists potentiated the estrogen-induced CCK mRNA expression in the medial preoptic nucleus. Together, these results suggest that endogenous opioid peptides may modulate the estrogenic upregulation of CCK mRNA expression and demonstrate an important level of regulation of gene expression in which synaptic activity modifies hormonal input.

Induction of CCK mRNA levels in the limbic-hypothalamic circuit: time course and site-specific effects of estrogen.

Estrogenic regulation of cholecystokinin (CCK) and its receptors is correlated with the initiation and termination of lordosis behavior. To understand the effect of circulating estrogen concentration on the temporal aspects of CCK mRNA expression in the posterodorsal medial amygdaloid nucleus (MeApd) and the central part of the medial preoptic nucleus (MPNc) of the limbic-hypothalamic circuit, ovariectomized female rats were treated with a 10 mm Silastic capsule filled with estradiol, a bolus injection of 50 micrograms estradiol benzoate or 2 micrograms estradiol benzoate every 4 days for five "cycles." In situ hybridization was used to compare the relative changes of CCK mRNA levels at 0 h to levels measured at 6, 12, 24, 48, 72, or 96 h after estrogen administration. In the MPNc and the MeApd, the 10-mm capsule significantly increased and maintained CCK mRNA levels from 6 to 96 h. The range of the increase was 3.0-5.1-fold in the MPNc and 2.8-5.0 in the MeApd. The 50-micrograms injections significantly increased and maintained CCK mRNA levels in the MPNc from 12 to 96 h (range of the increase 2.4-4.1-fold) and in the MeApd from 24 to 96 h (range of the increase 2.2-2.8-fold). The repeated administration of 2 micrograms estrogen induced a significant increase of message levels in the MPNc at 12 and 24 h that were 4.2- and 4.7-fold, respectively. In the MeApd this estrogen treatment did not significantly increase CCK mRNA. These studies demonstrate that small doses (2 micrograms) of estrogen that mimic the pattern and circulating levels of estrogen dramatically stimulate CCK mRNA levels in the limbic-hypothalamic circuit. To further study this steroid stimulation, ovariectomized female rats were implanted with estradiol-filled cannulae into the bed nucleus of the stria terminalis or MeA. Estrogen elevated CCK mRNA levels locally in each nucleus. Implants in the bed nucleus also elevated CCK mRNA levels in the MeApd indicating that physiologic estrogen stimulation of CCK in the MeApd is the result of both local and distal transsynaptic elevation of CCK mRNA levels. The sitespecific induction of CCK mRNA levels within the limbic-hypothalamic nuclei provides another important facet of estrogenic modulation of CCK induction.

Inhibition of erythromycin-resistant propionibacteria on the skin of acne patients by topical erythromycin with and without zinc.

Propionibacteria resistant to high concentrations of erythromycin [minimal inhibitory concentration (MIC) > or = 0.5 mg/ml] are now commonly isolated from the skin of antibiotic-treated acne patients. This double-blind study was carried out to assess the ability of 4% w/v erythromycin with and without 1.2% w/v zinc acetate to reduce the numbers of erythromycin-resistant propionibacteria in vivo, and also to monitor the acquisition of resistant strains de novo during therapy. Under laboratory conditions, erythromycin-resistant propionibacteria were shown to be as sensitive to zinc acetate as fully sensitive strains. In vivo, the erythromycin/zinc complex and erythromycin alone produced highly significant reductions in total propionibacteria (P < 0.001) and in the number of erythromycin-resistant strains (P < 0.001 at 8 weeks). After 12 weeks, resistant propionibacteria were reacquired, or acquired de novo, by three patients treated with erythromycin alone and four patients treated with the erythromycin/zinc complex. In contrast, changes in numbers of Micrococcaceae were slight and, after 12 weeks, erythromycin-resistant strains were predominant in both treatment groups. In vitro MIC determinations suggested that this finding might be explained by the exceptionally high degree of erythromycin resistance displayed by some staphylococcal strains (MIC > 4 mg/ml) and by the relative insensitivity of all staphylococcal strains to zinc acetate. Erythromycin with and without zinc was clinically effective, and both preparations produced significant reductions in acne grade, and inflamed and non-inflamed lesion counts (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Vancomycin-resistant Corynebacterium species causing prosthetic valve endocarditis successfully treated with imipenem and ciprofloxacin.

Endocarditis caused by a Corynebacterium sp. resistant to vancomycin, penicillin G, erythromycin, gentamicin and rifampicin arose in a 44-year-old woman 4 months after replacement of the mitral valve with a prosthesis. She was successfully treated with a 79-day course of intravenous imipenem and ciprofloxacin and replacement of the prosthesis 48 days after treatment began.

Identification of a median thalamic system regulating seizures and arousal.

This study better defines the way in which the thalamus controls expression of experimental generalized seizures. The effects of small intrathalamic injections of the direct GABA agonist muscimol on the thresholds of pentylenetetrazol (PTZ)-induced seizures and on spontaneous behavior were determined in the rat and compared with the effects of injections of gamma-vinyl-GABA (GVG), an irreversible inhibitor of GABA transaminase. Muscimol injections produced neuronal inhibition in a relatively small area of thalamus, whereas GVG injections produced inhibition in a much larger area. Muscimol injections in the midline thalamus in the vicinity of the paraventricular, paratenial, interanteromedial, intermediodorsal, and central medial nuclei facilitated PTZ myoclonic and clonic seizures and also produced sedation. These effects on seizure thresholds were attributable both to a lower PTZ threshold dose for initiation of electroencephalographic (EEG) seizure activity and to an increased probability of this EEG activity being expressed as behavioral seizures. Midline injections located more posteriorly in the thalamus also inhibited tonic seizures. Muscimol injections placed laterally, dorsally, or ventrally to this midline thalamic region had much less effect on behavior or seizures. In contrast, GVG injections in the anterior medial thalamus elevated the threshold for all PTZ seizure types and for associated EEG seizure activity but had little effect on spontaneous behavior. These findings demonstrate the existence of an important seizure regulatory system in the midline of the thalamus and a direct anatomic link between the mechanisms for regulating arousal and seizure production which may help explain the association between sleep and seizure facilitation in humans.(ABSTRACT TRUNCATED AT 250 WORDS)