Refractive outcomes after cataract surgery with primary lens implantation in infants.

AIMS: To show the refractive outcomes, accuracy of intraocular lens power selection, and visual outcomes and complications in infants undergoing cataract surgery. METHODS: The refraction (spherical equivalent) of 14 operated eyes in 8 children aged <1 year was plotted over time. Preoperative and final recorded visual acuities were assessed. RESULTS: The median follow-up was 37.25 months. The median initial postoperative refraction was (+)6.75 dioptres. CONCLUSIONS: Refractive outcomes for each eye were not entirely predictable and were variable between infants. However, there was a consistent pattern in each infant who underwent bilateral surgery, with both eyes following a similar pattern of refractive change with time: a decreasing myopic shift was seen in 8 eyes, possibly demonstrating emmetropisation. The two unilateral cases appeared to show a linear myopic shift. 4 eyes in 2 patients did not follow a myopic shift curve and one of these patients showed an early trend towards increased hyperopia. Definite causes for this erratic refractive change were not identified. A postoperative refraction >4.5 dioptres avoided early onset myopia. The range of difference between postoperative and predicted refraction using SRK-T was (-)2.85 to 2.97 dioptres. Most of the visual results are encouraging compared with historical data in older children.

Enhancing clinical practice through the use of electronic resources.

This article discusses the development of a web-based resource to support students in their learning, especially those engaged in problem-based learning. The Students Online in Nursing Integrated Curricula website has been evaluated and used in different settings (www.uclan.ac.uk/sonic). This open-access website can be used by students, mentors, practice educators and lecturers to support learning in a variety of settings.

Regeneration of cercal filiform hair sensory neurons in the first-instar cockroach restores escape behavior.

Neural regeneration in the escape circuit of the first-instar cockroach is described using behavioral analysis, electrophysiology, intracellular staining, and electron microscopy. Each of the two filiform hairs on each of the animal's cerci is innervated by a single sensory neuron, which specifically synapses with a set of giant interneurons (GIs) in the terminal ganglion. These trigger a directed escape run. Severing the sensory axons causes them to degenerate and perturbs escape behavior, which is restored to near normal after 4-6 days. Within this time, afferents regenerate and reestablish arborizations in the terminal ganglion. In most cases, regenerating afferents enter the cercal glomerulus and re-form most of the specific monosynaptic connections they acquired during embryogenesis, although their morphology deviates markedly from normal; these animals reestablish near normal escape behavior. In a few cases, regenerating afferents remain within the cercus or bypass the cercal glomerulus, and thereby fail to re-form synapses with GIs; these animals continue to exhibit perturbed escape behavior. We conclude that in most cases, specific synapses are reestablished and appropriate escape behavior is restored. This regeneration system therefore provides a tractable model for the establishment of synaptic specificity in a simple neuronal circuit.

The influence of Florence Nightingale's image on Liverpool nurses 1945-1995.

Images of Florence Nightingale have been crystallised over time so that an iconoclastic image is frequently presented. Using oral history as a research method, a convenience sample of Liverpool nurses, spanning the period 1945-1995 discussed how this image had a bearing on them as nurses and on their practice. It would appear that during their training, lectures were about Florence Nightingale as a person and students were expected to emulate her. The influence of the image led to a rigorous attention to detail in the work and their persona. Over time, this influence has diminnished through the many changes experienced in the delivery of healthcare. However, it is contended that if attention was paid to Nightingale's works rather than her image, there could have been a resurgence of interest which might have influenced practice.

Early infection and subsequent insulin dependent diabetes.

In a study of 58 children under the age of 16 with insulin dependent diabetes (IDDM) and 172 matched non-diabetic controls, infection during the first year of life was associated with a reduction in diabetes risk (odds ratio 0.81, 95% confidence interval 0.67 to 0.98, per infective episode). Decreased exposure to common infections during infancy may be linked with subsequent IDDM.

Expression of engrailed in an array of identified sensory neurons: comparison with position, axonal arborization, and synaptic connectivity.

engrailed (en) is expressed in the posterior region of embryonic segments and appendages of the cockroach, Periplaneta americana. By 23% of embryogenesis En immunoreactivity is apparent in the dorsal half of the cercus, appendages of segment A11. By 40% of development, En staining is present in the dorsomedial half of the cercus. The nucleus of the medial filiform hair sensory neuron (M), born in this region, expresses en strongly. Staining is never seen in the lateral neuron (L). En is expressed in M as the sensory axons enter the terminal ganglion and begin to form their different arborizations and synaptic connections. This pattern of expression persists through development to the second instar. In mutant animals with supernumerary filiform hair sensilla, En immunoreactivity is only seen in the medial neurons. In second-instar and adult cerci en expression is also seen in medially located neurons. We compared the levels of En staining in the array of 25 second instar neurons with their position, axonal arbor type, and synaptic connections. Staining intensity correlates with distance from the cercal midline, suggesting that en is regulated by other circumferential positional determinants. The expression of en does not correlate with the formation of an M-type arbor. Although 10 to 12 sensory neurons that express en form synapses with giant interneuron 5, the correlation is not precise. These results suggest that, if En does form part of a combinatorial system of positional information in the cercus, its actions are modulated by other gene products.

Cellular colocalization of diuretic peptides in locusts: a potent control mechanism.

Locust abdominal ganglia are shown to colocalize Locusta-diuretic peptide-, leucokinin I-, and lysine vasopressin-like immunoreactivity in posterior lateral neurosecretory cells. Extracts of abdominal ganglia were partially purified by RP-HPLC then dot immunoassay screened with the same antisera used for immunocytochemistry. Locusta-diuretic peptide-like immunoreactive material coeluted with synthetic Locusta-diuretic peptide, and leucokinin-like immunoreactive material coeluted with locustakinin. Lysine vasopressin-like material eluted in fractions that also showed Locusta-diuretic peptide and leucokinin I immunoreactivity. The diuretic activity of synthetic Locusta-diuretic peptide and locustakinin is demonstrated, and they are shown to act at least additively to promote Malpighian tubule fluid secretion. The immunoreactive neurosecretory cells are assumed to express at least these two peptides, and a model for promoting fluid secretion is proposed.

Localization of Locusta-DP in locust CNS and hemolymph satisfies initial hormonal criteria.

Locusta-diuretic peptide (Locusta-DP) is a potent stimulant of fluid secretion and cyclic AMP production by locust Malpighian tubules. In this study, a polyclonal antiserum raised to the C-terminus of Locusta-DP reveals a wide distribution of immunoreactive cell bodies and processes throughout the CNS, and endings in two important neurohemal release sites: the corpora cardiaca and the perivisceral organs. HPLC fractionation of CNS, neurohemal structures, and hemolymph reveals immunoreactive material that coelutes with synthetic Locusta-DP and stimulates cyclic AMP production by locust tubules. The identity of the immunoreactive and biologically active material is confirmed as authentic Locusta-DP by mass spectrometry.

Setting standards in diabetes education.

The project described in this article was undertaken to develop and improve the levels of nursing knowledge on diabetes mellitus and subsequently improve the quality of patient education on diabetes. A written standard on health education was devised and an educational programme for nurses was implemented to prepare nurses to meet the requirements of the standard. The project is ongoing, and initial results suggest that while there have been problems, nurses appear to be more confident in assuming their roles as patient educators.

Correlation of filiform hair position with sensory afferent morphology and synaptic connections in the second instar cockroach.

An attempt is made to relate the distribution of filiform hairs on the cercus of the second instar cockroach, Periplaneta americana, to the morphology and patterns of synaptic connectivity of their afferents. We studied the most distal 25 of the 39 filiform hairs which are commonly present. Filiform afferent arborizations were stained by cobalt filling from the cell body in the cercus. Three fundamental arbor types were found, two similar to those of the first instar medial (M) and lateral (L) afferents, and a third, novel type. L-type arbors could be divided into four subtypes. The most obvious correlate of arbor type is the circumferential position of the hair on the cercus. The proximodistal position of the sensillum within each cercal segment is also a determinant of its arbor. By comparison of hair positions and afferent morphologies, we were able to ascribe homologies between the second instar hairs and members of adult longitudinal hair columns. The patterns of monosynaptic connections between afferents and giant interneurons (GIs) 1, 2, 3, 5, and 6 were determined by recording synaptic potentials in GIs evoked by direct mechanical displacement of individual filiform hairs. Latency from stimulus onset to the rise phase of the first excitatory postsynaptic potential (EPSP) was used as the criterion of monosynapticity. The EPSP amplitudes of the two original L and M afferents are halved in the second instar, in the absence of a significant decrease in GI input resistance. The other afferents can be divided into two basic classes: those which input to GI5 (M-type), and those which input to GI3 and GI6 (L-type). The former is correlated with a central or medial position, while the latter is associated with a group of afferents situated laterally on the cercus. In segments 3 and 4, input to GIs 1 and 2 also correlates with a medial cercal position, however, in the more proximal segments 5 and 6, afferents at all positions input to these interneurons. The occurrence of afferents of identical morphology and similar connectivity in equivalent positions in different segments suggests that each sensory neuron is determined by its two-dimensional position within a segment. The presence of afferents with the same morphology which display proximodistal differences in synaptic connectivity, and of other afferents which have M-type connectivity despite L-type morphology, means that anatomy is generally a poor predictor of synaptic connectivity.

Contract learning in a clinical context: report of a case study.

Contract learning as a method of learning has created considerable interest in recent years. The author first discusses contract learning briefly, and reviews the literature, particularly with reference to contracts in nurse education in both the UK and USA; its application in the clinical area in the UK receives specific attention. Secondly the author discusses, the establishment, compilation and enactment of a learning contract with a student nurse within the author's workplace followed by a critical analysis and evaluation of the contract.

Examination of the bronchoconstrictor response of guinea-pig isolated lung to beta-phenylethylamine.

beta-Phenylethylamine (PEA) produced a contraction of the guinea-pig isolated lung parenchymal strip and bronchoconstriction of perfused lungs. Reserpine pretreatment had little effect on these responses indicating a substantial direct effect. Phentolamine (10(-6) and 10(-5) M) had minimal effect on PEA in the lung strip compared with that on noradrenaline, eliminating involvement of alpha-adrenoceptors. PEA was unaffected by atropine (10(-7)M) or a mepyramine (10(-7)M); metiamide (10(-4)M) mixture. The contraction was not therefore mediated via muscarinic or histaminergic receptors. 5-HT and dopamine receptors were also discounted. Possible stimulation of a phenylethylaminergic receptor and its relevance to bronchial asthma is discussed.