A reduced stimulation unit: effects on patients with Alzheimer's disease and related disorders.
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Aged↗
Biomedical subjects
M Price
Publications and source records attributed to M Price.
An unusual case of upper airways obstruction.
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Airway Obstruction↗
Improving recovery following cardiac surgery: a randomized clinical trial.
To enhance individual and family health during recovery from heart surgery, this study employed nursing interventions based on self-efficacy and family stress theory during the hospitalization period and for 3 months thereafter. The effectiveness of the interventions were assessed through a randomized trial in which 67 prospective bypass and valve surgery patients, aged 30-77 years, and their spouses, were allocated either the experimental interventions or usual care and followed for 6 months. At 3 months post-surgery, the only statistically significant differences between the experimentals and controls were on perceived self-efficacy for lifting and tolerating emotional distress. At 6 months no significant differences were found on individual or family measures. Analyses revealed that age, gender and preoperative cardiac status significantly affected individual recovery. The study is continuing with a larger sample in order to explicate the recovery process and to better determine whether a low intensity nursing intervention can effect changes in individual and family recovery.
Adult↗
Uteroplacental perfusion after epidural analgesia for elective caesarean section.
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Analgesia, Epidural↗
Volume response of quiescent and interleukin 2-stimulated T-lymphocytes to hypotonicity.
Regulatory volume decreased (RVD) in lymphocytes in response to hyptonically induced swelling is dependent on the membrane permeabilities of K+, Cl-, and H2O. We used electronic cell sizing, cell water determination, and the whole cell patch-clamp method to study these membrane permeabilities in the cloned mouse T-lymphocyte, L2. Quiescent L2 cells express low levels of a voltage-gated K+ channel and show no RVD at 25 degrees C. In contrast, L2 cells stimulated to proliferate with the growth factor interleukin 2 have increased K+ conductance and show RVD in response to hypotonicity. RVD in stimulated cells is blocked by quinine and verapamil at levels that also completely block the voltage-gated K+ conductance. Swollen, unstimulated L2 cells can be induced to shrink by addition of the monovalent cation ionophore gramicidin in the presence of impermeant extracellular organic cations; gramicidin also enhances the rate of RVD in stimulated cells. Additionally, the anion transport inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) blocks this gramicidin-facilitated RVD. These results suggest that a minimum requisite Cl- permeability is present even in the unstimulated L2 cells, that a necessary and limiting K+ permeability determines the rate of RVD, and that this K+ permeability increases after growth-factor stimulation as predicted from the direct measurement of voltage-gated K+ conductance. The hydraulic permeability is approximately 70% greater in proliferating L2 cells than in quiescent cells. At 37 degrees C, some RVD occurs in unstimulated L2 cells, and stimulated cells show faster and more complete shrinkage. These results are discussed with respect to the underlying membrane permeabilities and their relation to stimulated cell proliferation.
Animals↗
MK-801 powerfully protects against N-methyl aspartate neurotoxicity.
Using the ex vivo chick embryo retina to study the efficacy of antagonists in blocking the excitotoxic effects of excitatory amino acid agonists, we previously identified phencyclidine as the most powerful known anti-excitotoxin. Here we show that MK-801 is 5 times more powerful than phencyclidine as an anti-excitotoxin, that its antagonism is specific for N-methyl-asparate toxicity, is non-competitive and does not entail inhibition of excitatory amino acid receptor binding.
Animals↗
Selectivity of pirenzepine in the central nervous system. III. Differential effects of multiple pirenzepine and scopolamine administrations on muscarinic receptors as measured autoradiographically.
The effects of intrahippocampal injections of scopolamine and pirenzepine on muscarinic receptor binding were examined by quantitative autoradiographic techniques. Brain slices from animals which had received 7 injections of either scopolamine (n = 5) or pirenzepine (n = 5) over a 22-day injection schedule were compared with slices from 5 saline-injected controls for receptor binding to the whole slice and within selected regions of the brain as measured autoradiographically. The total number of receptors was determined from direct binding assays with 1-[3H]quinuclidinyl-benzilate ([3H]-1-QNB), while the binding of the selective ligands pirenzepine, carbamylcholine, and scopolamine was examined through inhibition studies. The data from the whole slices indicated that pirenzepine-treated animals contained more receptors for [3H]-1-QNB than either saline- or scopolamine-injected controls. Slices from the same animals also displayed a lower affinity for pirenzepine. Slices from scopolamine-injected animals revealed neither an increase in receptor number nor a decrease in antagonist affinity, although the binding of the agonist carbamylcholine was increased. Quantitative analysis of the autoradiograms generated from the slices indicated that the increase in receptor number for pirenzepine-injected animals was predominantly within the cerebral and cingulate cortices. The inhibition by pirenzepine was also lower in these areas in the same group of animals. Agonist inhibition was altered in the central layers of the cerebral cortex and in the pretectal area in scopolamine-treated animals. The results suggest separate mechanisms of drug action and adaptation for pirenzepine and scopolamine.
Animals↗
The use of psychophysical, structural, and electrodiagnostic parameters to identify glaucomatous damage.
Fifty-one patients with early glaucoma and 29 patients without the disease had their contrast sensitivity, colour vision, differential light threshold, neuroretinal rim area, retinal nerve fibre layer, pattern-reversal electrogram and visually evoked potential examined. A stepwise discriminant analysis found that the combination of the vertical cup disc ratio, the diffuse nerve fibre layer score and the localized nerve fibre layer score correctly identified 98% of the normals and 84% of the glaucoma patients. Single parameters and various combinations of parameters were also examined for their ability to discriminate between the two groups. Fifty-two glaucoma suspects were similarly examined and were classified into those whose discriminant functions were normal or abnormal.
Electrodiagnosis↗
Betakid--lessons learned while developing a microcomputer pediatric case simulation.
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Adolescent↗
Regional distribution of muscarinic receptors preferring gallamine in the rat brain.
The regional distribution of muscarinic receptors recognized by the antagonist gallamine was determined autoradiographically by the ability of gallamine to reduce the binding of [3H]quinuclidinyl benzilate in rat brain slices. The inhibition data obtained from indirect binding assays on whole slices indicated that gallamine distinguished at least two sites with differing affinities. Analysis using a two-site model gave Kh = 0.6 microM, K1 = 10 microM. The regions of highest and lowest affinity for gallamine were apparent qualitatively by visual inspection of the autoradiograms. A number of regions in coronal sections at three different levels were compared by microdensitometry. Gallamine possessed greater overall affinity for the diencephalon and brainstem than for the forebrain. Within the forebrain, the septal nucleus was unique in that it displayed high affinity for gallamine. Within the brainstem, the superior colliculus had the greatest proportion of sites with high affinity for gallamine. In general, the binding profile of gallamine was opposite to that of the antagonist pirenzepine and similar to that of the agonist carbachol, suggesting that gallamine is selective for M2 muscarinic receptors.
Animals↗
The correlation of functional and structural measurements in glaucoma patients and normal subjects.
We measured a number of structural characteristics of the optic nerve head and retina in 52 glaucoma suspects, 51 glaucoma patients, and 28 normal eyes. In all of the patients, a number of psychophysical functions were recorded and evoked cortical potentials and pattern electroretinography were obtained. The correlations between these structural and functional parameters were established by multiple regression. Diffuse structural changes in the optic nerve head and retina were related to differential light threshold and color that measure diffuse psychophysical disturbances. Localized changes in the retinal nerve fibers and the vertical cup/disk ratio related to the "corrected loss variance," which is an index measuring localized psychophysical changes.
Glaucoma↗
The mouse myoglobin gene. Characterisation and sequence comparison with other mammalian myoglobin genes.
Seal myoglobin (Mb) exons 1 and 3 were used as probes to isolate the functional mouse Mb gene. This gene has a very low level of Mb expression in skeletal muscle. Although it is shorter, the mouse Mb gene displays the common organisation found in human and seal Mb genes. In addition, we have defined blocks of conserved sequences in the 5' flanking region by comparison with other mammalian Mb genes. Moreover, about 10(3) bases upstream of the cap site we identified a repetitive B1 element directly associated with two overlapping open reading frames, containing a putative polyadenylation signal. A polypyrimidine-rich region has also been located upstream from the gene.
Animals↗
N-methylaspartate: an effective tool for lesioning basal forebrain cholinergic neurons of the rat.
The ability of the excitotoxin, N-methyl-D,L-aspartic acid (NMA), to destroy basal forebrain cholinergic (BFC) neurons was evaluated. NMA (100 nmol) was directly injected into the peripallidum, a region containing a proportionately large number of cortically-projecting BFC neurons. Cholineacetyltransferase (ChAT) activity 10 days later was markedly and significantly reduced (up to 62%) in the cortex ipsilateral to the lesion. NMA induced a focal lesion affecting BFC neurons without damaging axons of passage or causing lesions distant from the site of injection. ChAT immunohistochemistry (IHC) was used to directly demonstrate loss of ChAT-positive neurons from the lesion site. This loss persisted at all survival times examined, from 2 days to 7.5 months post-injection.
Animals↗
Color vision and retinal nerve fiber layer in early glaucoma.
We tested 47 eyes in 47 patients (ten normal subjects, 15 with suspected glaucoma, and 22 with glaucoma) with the Pickford-Nicholson anomaloscope to assess the retinal nerve fiber layer and measure color vision. The 47 subjects were randomly selected from a group of 132 for whom Farnsworth-Munsell 100-hue color error scores were known. The yellow-blue and green-blue anomaloscopic matching ranges correlated significantly with diffuse retinal nerve fiber loss. There was no correlation with localized retinal nerve fiber loss.
Adult↗
Increased potassium permeability in erythrocytes from patients with hyperparathyroidism.
Parathyroid hormone (PTH) has been shown to modify Ca2+ and Na+ transport in several epithelia. The molecular mechanisms of these effects are poorly understood. We investigated here whether PTH may modify Na+ and K+ transport across the human red blood cell membrane in vitro and ex vivo. Fourteen patients with severe primary or secondary hyperparathyroidism and hypercalcemia were studied before and 5-7 days after surgical parathyroidectomy. Erythrocyte ouabain-sensitive as well as furosemide-sensitive Na+ efflux rates of the patients were comparable to that of healthy volunteers and remained unchanged after parathyroidectomy. Moreover, erythrocyte Na+ fluxes of control subjects remained unchanged when red blood cells were incubated in the presence of 1.0 IU/ml of bovine PTH (1-85). However, erythrocytes from hyperparathyroid patients showed a significant increase in passive K+ permeability when compared to that of healthy controls (p less than 0.05). This abnormality could be corrected in vivo after parathyroidectomy and in vitro using quinine, respectively. It is concluded that hyperparathyroidism induces a moderate increase in Ca2+ dependent K+ permeability of erythrocytes ("Gardos effect") which is reversible after parathyroidectomy.
Adult↗
Myoglobin expression: early induction and subsequent modulation of myoglobin and myoglobin mRNA during myogenesis.
We showed that myoglobin gene transcription and the appearance of myoglobin occur very early in myogenesis, in both humans and mice. In contrast to the contractile protein genes, there is a subsequent increase of 50- to 100-fold in myoglobin mRNA and protein levels during later muscle development. Myoglobin and myoglobin mRNA are present at elevated levels in fetal heart and are also detectable at low levels in adult smooth muscle. The absolute level of myoglobin mRNA in highly myoglobinized seal muscle is very high [2.8% of the total population of poly(A)+ RNAs]. Levels of myoglobin in seal skeletal muscle and in various human muscle types appear to be determined by the size of the myoglobin mRNA pool. In contrast, low levels of myoglobin in mouse skeletal muscle are not apparently correlated with low levels of myoglobin mRNA. As expected from the early appearance of myoglobin mRNA in embryonic skeletal muscle, both rat and mouse embryonic myoblasts accumulate myoglobin mRNA on fusion and differentiation in vitro.
Actins↗
Effect of diuretic therapy on ventricular arrhythmias in hypertensive patients with or without left ventricular hypertrophy.
Recent studies have suggested that hypertensive patients with ECG evidence of left ventricular hypertrophy (LVH) may have increased risk of sudden death when treated with diuretics. In the present study echocardiography was used as a more sensitive index for the presence of LVH. Thirty-one patients with uncomplicated hypertension underwent 48-hour ambulatory ECG monitoring both before any treatment and after 4 weeks of hydrochlorothiazide, (HCTZ), 100 mg daily. In 18 patients with left ventricular posterior wall thickness (LVPWT) greater than or equal to 13 mm (average = 14.4 +/- 0.2 mm) on echocardiogram, plasma potassium decreased from 4.1 +/- 0.3 to 3.3 +/- 0.4 mEq/L with HCTZ (p less than 0.01). Premature ventricular contractions (PVCs) averaged 5.7 +/- 9.9/hr at baseline and 7.1 +/- 16.6/hr following HCTZ (p = NS). The total number of couplets was 29 before and 13 after HCTZ, while four brief runs of ventricular tachycardia occurred only before treatment. In the remaining 13 patients with LVPWT less than or equal to 12 mm (average = 11.2 +/- 0.1 mm), plasma potassium decreased from 4.1 +/- 0.3 to 3.4 +/- 0.5 mEq/L with HCTZ (p less than 0.01). The average number of PVCs was 4.3 +/- 8.0/hr after HCTZ (p = NS). One couplet and one 3-beat run of ventricular tachycardia occurred before and one 3-beat run of ventricular tachycardia after HCTZ. Although more complex arrhythmias were noted in the LVH group, the differences were not statistically significant. These results indicate that thiazide therapy does not increase ventricular arrhythmias either in patients with or without LVH.
Adult↗