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Vivian A. Blacker James P. McLennan 《Australian and New Zealand journal of public health》1987,11(1):31-37
This paper reports a survey of program evaluation and service monitoring activity in 49 Victorian community health centres. Centres generally have not made evaluation and monitoring an important part of their operations despite the rhetoric of health services policy makers and administrators. Reasons for this include a lack of staff in centres who are trained in evaluation methods; the reluctance of centre staff to divert time and resources from service provision to evaluation; and insufficient assistance to centres from the Health Commission of Victoria. “The assumptions that operating a service is equivalent to rendering service and that both are equivalent to rendering quality service are no longer being honoured as inherently valid.”1 相似文献
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The actions of the neurotoxic amino acids folate and kainate have been compared on ortho-and antidromic responses evoked in CA1, CA3 and the dentate gyrus of slices of rat hippocampus maintained in vitro. Both in CA1 and the dentate gyrus superfusion of these acids caused an increase in amplitude of the population spike discharging from an excitatory postsynaptic potential which either remained unaffected or was reduced. In the CA3 region kainate and folate had broadly similar actions to enhance the probability of cell firing to synaptic excitation, and also caused epileptiform discharges to occur spontaneously or in response to electrical stimulation. Spontaneous and evoked population bursts in CA3 did not persist in low calcium/high magnesium medium indicating their dependence on intact synaptic transmission; spontaneously occurring bursts in CA1 were eliminated with the latter treatment or when the axonal connections between it and CA3 were cut. Following folate superfusion the commissural-evoked response in CA3 showed large and variable shifts of the latency which were dependent on the stimulus intensity and its timing after a spontaneous population discharge. Although all of the effects of folate were reproduced by bicuculline, no evidence for a decreased recurrent inhibition in CA1 was obtained although this was observed with kainate. The finding that folate and kainate produced their effects in the absence of a detectable effect on the antidromic population spike suggests a mechanism of action other than neuronal depolarization. The implications of these data for the neurotoxic mechanism(s) and the receptor homologies of folate and kainate are discussed. 相似文献
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McLennan NF Brennan PM McNeill A Davies I Fotheringham A Rennison KA Ritchie D Brannan F Head MW Ironside JW Williams A Bell JE 《The American journal of pathology》2004,165(1):227-235
The function of the normal conformational isoform of prion protein, PrP(C), remains unclear although lines of research have suggested a role in the cellular response to oxidative stress. Here we investigate the expression of PrP(C) in hypoxic brain tissues to examine whether PrP(C) is in part regulated by neuronal stress. Cases of adult cerebral ischemia and perinatal hypoxic-ischemic injury in humans were compared with control tissues. PrP(C) immunoreactivity accumulates within neuronal processes in the penumbra of hypoxic damage in adult brain, and within neuronal soma in cases of perinatal hypoxic-ischemic injury, and in situ hybridization analysis suggests an up-regulation of PrP mRNA during hypoxia. Rodents also showed an accumulation of PrP(C) in neuronal soma within the penumbra of ischemic lesions. Furthermore, the infarct size in PrP-null mice was significantly greater than in the wild type, supporting the proposed role for PrP(C) in the neuroprotective adaptive cellular response to hypoxic injury. 相似文献
6.
A peripheral blood smear from a patient with probable splenic lymphoma with villous lymphocytes (SLVL) showed clumping of lymphoma cells. The clumping was not seen in films made from unanticoagulated blood, and has not been previously described in lymphomas. The patient also had metastatic prostatic adenocarcinoma for 30 months before lymphoma was diagnosed and the clumped cells posed diagnostic problems. 相似文献
7.
Diadenosine polyphosphates induce intracellular Ca2+ mobilization in human neutrophils via a pertussis toxin sensitive G-protein. 下载免费PDF全文
The diadenosine polyphosphates diadenosine 5',5"'-P1,P3-triphosphate (Ap3A), diadenosine 5',5"'-P1,P4-tetraphosphate (Ap4A), diadenosine 5',5"'-P1,P5-pentaphosphate (Ap5A) and diadenosine 5',5"'-P1,P6-hexaphosphate (Ap6A) all stimulated increases in intracellular Ca2+ in human neutrophils. Maximal increases in intracellular Ca2+ of 650 nM were obtained at dinucleotide concentrations of 500-700 microM. These increases in intracellular, Ca2+ were completely abolished by pre-treatment of the neutrophils with pertussis toxin and were hardly affected when the extracellular buffer was devoid of Ca2+. On the other hand, adenosine triphosphate (ATP) could stimulate much greater increases in intracellular Ca2+ (up to 1.1 microM) at much lower concentrations (half maximal responses obtained at around 5 microM ATP). Receptor de-sensitization experiments indicate that human neutrophils may possess two types of P2-purinoceptors. The first of these may bind ATP (but not the dinucleotides) with high affinity whilst the second may bind the dinucleotides with lower affinity and also bind ATP. 相似文献
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Confusion still exists about the roles and functions of social workers in the mental health care system. The authors discuss this role ambiguity and its effects. They then present and discuss the findings of a study that explored the current role of the social worker in Ontario psychiatric hospitals with the following objectives: to document social workers' major roles and activities; to assess role satisfaction; to assess involvement in decision making; and to identify major types of therapy used. 相似文献
9.
Interactions of the systemic and brain renin-angiotensin systems in the control of drinking and the central mediation of pressor responses. 总被引:3,自引:0,他引:3
Most of the biological actions of the circulating (a.k.a., the systemic or blood-borne) renin-angiotensin system require the generation of the octapeptide angiotensin (ANG) II from the decapeptide ANG I. In the case of circulating ANG I, the lungs are generally considered the major site for this conversion. The present experiments explored the possibility that under conditions of marked elevations of blood-borne ANG I, the generation of ANG II takes place within brain-associated target tissues, most notably circumventricular organs (CVOs) that lack a blood-brain barrier. The first important result of these experiments demonstrates that intracerebroventricular (i.c.v.) infusion of the converting enzyme inhibitor, captopril, completely blocks the drinking response and significantly attenuates the pressor response produced by systemically infused ANG I. This result indicates that under physiological/pathophysiological conditions associated with large elevations of circulating ANG I, an important part of the biological responses derived from blood-borne ANG may result from local conversion of ANG I to ANG II within specific brain target tissues which have high concentrations of converting enzyme. This local conversion process provides an important mechanism that would act to reinforce the "classic" conversion process which takes place in the lungs thereby delivering more ANG II immediately to central target receptors. The second important finding from these studies showed that drinking produced by systemically infused ANG II was not attenuated by an i.c.v. dose of captopril which was effective in blocking a comparable dipsogenic response induced by i.v. ANG I. This observation suggests that drinking induced by systemic ANG II does not require an intact metabolic cascade within the brain for the formation of ANG II (or ANG II-like effector peptide) from ANG I. 相似文献
10.
The fine structure of the abdominal ganglion of Aplysia californica has been studied in preparations fixed by immersion in aldehydes, either directly or after a survival of a few hours in artificial sea water. The central core of neuropil is surrounded by a rind of neuronal cell bodies floating in a subcapsular space containing a loose meshwork of neuronal and glial processes, separated by wide extracellular spaces. Large primary processes with deeply infolded membranes leave the neuronal perikarya and enter the neuropil where they branch into smaller processes containing either neurofilaments, neurotubules or both. Some have the appearance of initial segments. The neuropil is not a homogeneous structure. Rather, four types of zones can be distinguished: (1) zones of fibers of passage coursing together in the neuropil and making few synaptic contacts: (2) zones of neurosecretory fibers containing large granules and dense-core vesicles, again making few synaptic contacts: (3) zones with a great variety of synaptic contacts between medium size and small profiles; and (4) glomerular zones. The differentiated membranes of the synapses are characterized by a slight increase in density and by being regularly parallel to each other. Presynaptic densities are sometimes quite prominent but specialized dense cytoplasmic opacities have never been seen bordering the postsynaptic membranes, i.e., all synapses are of the symmetrical type. Interlemmal opacities vary considerably in density. In zone 3, the synaptic vesicles are of several sizes, are round, oval or flat, and are either clear or filled with different types of dense material. The population of vesicles within a single profile may consist either of a homogeneous group of similar vesicles or of various mixtures of two or three kinds of vesicles. In profiles with mixtures of clear and large dense-core vesicles, it is often only the clear vesicles which agglomerate towards the differentiated membranes. In such cases the large dense-core vesicles lie as a peripheral halo around the clear vesicles. Here, and especially in other large neuronal profiles not forming contact in the plane of section, they can be seen to associate specifically with mitochondria and glycogen. It is proposed that they do not contain neurotransmitters but are related to mitochondrial activities such as the storage of ATP or the movement of calcium ions. In profiles with mixtures of clear and small dense-core vesicles, both types of vesicles often touch the presynaptic membrane, suggesting the release of two transmitters or of a modulator or neurohormone with a transmitter, by a single terminal. Serial synapses are present in this zone. The glomerular zones contain small profiles forming many synaptic contacts, some of which are arranged in such a way as to suggest the existence of "reciprocal" serial synapses. 相似文献