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Biomedical subjects

D Evans

Publications and source records attributed to D Evans.

At least 253 records · Page 14Linked to original sources
PubMed1991

Subcortical hyperintensities on brain magnetic resonance imaging: a comparison of normal and bipolar subjects.

Bipolar disorder has been reported to occur frequently in a number of subcortical diseases. This suggests that subcortical structures may be involved in the etiology of bipolar disorder in some patients. With the advent of brain magnetic resonance imaging (MRI), in vivo visualization of the subcortical white and gray matter is now possible, allowing the examination of these structures. The authors report a higher occurrence of deep white matter lesions in bipolar patients (44%) compared with age-matched controls (6%). The neuroanatomic and clinical correlates of these lesions will be discussed, along with their potential pathophysiologic significance.

Adult↗
PubMed1991

Educational programs for children with asthma.

During the last decade, research on the behavioral aspects of childhood asthma has focussed on three goals: (1) learning how families manage asthma at home and use health care services; (2) identifying specific problems they encounter in managing asthma, and (3) developing and evaluating educational programs to teach families to overcome these problems and to manage asthma effectively in the home environment. This paper will describe the research findings on the problems families face in managing asthma, review the available and evaluated health education programs that have been developed to solve them and suggest strategies for physicians and other health care providers to incorporate health education into routine office care for asthma.

Adaptation, Psychological↗
PubMed1991

Comparison of direct insertion of disposable and standard reusable laparoscopic trocars and previous pneumoperitoneum with Veress needle.

A randomized prospective study was conducted to evaluate the ease of use and safety of direct insertion of laparoscopic trocars. Comparison of previous pneumoperitoneum by Veress needle insertion with direct insertion of the reusable conventional laparoscopic trocar and direct insertion of the disposable shielded trocar revealed minor complication rates of 22, 6 and 0%, respectively. No major complications occurred in this series of 200 patients.

Female↗
PubMed1991

A review of referral patterns to paediatric dental consultant clinics.

A retrospective survey of 317 child patients referred to consultant paediatric dental clinics at Glasgow Dental Hospital over a 12-month period is reported. It was found that although there was a wide range of reasons for referral the most frequent problem was the management of the patient. As a result of this finding, the dental hospital is currently establishing a clinic specifically for patients with a fear of dental treatment.

Adolescent↗
PubMed1991

The secretory kinetics of the G cell in omeprazole-treated rats.

Prolonged achlorhydria leads to hypergastrinemia which must be matched by increased gastrin production. The extent to which the balance between synthesis and storage or secretion is shifted in achlorhydria remains uncertain. In the present study, rats were treated for 14 days with the hydrogen-potassium-stimulated ATPase inhibitor omeprazole, and the effects on plasma and tissue gastrin concentrations and on the abundance of gastrin messenger RNA were examined. To calculate the fractional release rates of gastrin, the metabolic clearance rate of synthetic unsulfated rat heptadeca peptide gastrin in anesthetized rats was also measured. Treatment with omeprazole for 14 days led to a profound hypergastrinemia, a twofold increase in antral gastrin stores, and a tenfold increase in messenger RNA. Calculations based on the metabolic clearance rate for rat heptadecapeptide gastrin suggested that in control rats, about 0.08% of stored gastrin was released per minute compared with about 0.4% in omeprazole-treated rats. No evidence was observed to suggest that changes in the efficiency of conversion of Gly-extended gastrins to amidated peptides were of any significance in accounting for the increased production of amidated gastrin. The increased gastrin synthesis in achlorhydria is therefore attributable to increased messenger RNA levels; most of the increase in gastrin production is directly secreted as changes in the stores of gastrin appear to be of lesser importance.

Animals↗
PubMed1990

Expression patterns of mRNAs for alpha-fetoprotein and albumin in the developing rat: the ontogenesis of hepatocyte heterogeneity.

In developing and normal adult rat liver the expression patterns of the mRNAs for alpha-fetoprotein (AFP) and albumin (ALB) were analysed by in situ hybridization using specific 35S-labelled complementary DNA probes. In the developing liver AFP and ALB mRNA are found from embryonic day (ED) 11 and 12, respectively, onward. At ED 20 the first signs of a zonal distribution of these mRNAs across the liver lobule can be observed, AFP mRNA concentration being higher in the pericentral area and ALB mRNA concentration higher in the periportal area. This distribution pattern of reciprocal, overlapping gradients of mRNA can be clearly recognized in the neonatal period. In the adult liver AFP mRNA can no longer be detected and similar to the neonatal situation, ALB mRNA is expressed across the entire porto-central distance decreasing in concentration going from the portal to the central area. Transient extra-hepatic expression of AFP mRNA is found in the embryonic heart and in the epithelial lining of intestine and lung; furthermore, AFP and ALB mRNA are found to be transiently expressed in the developing renal tubules. Similar expression patterns have been observed for other liver-characteristic mRNAs (Moorman et al., 1990), suggesting that common regulatory factors are operative during development.

Albumins↗
PubMed1990

Problems in the decision making process: a review.

Decision making is an integral part of the intensive care nurse's role, but many factors can disrupt this process. It is important that the nurse has an understanding of how defective decision making patterns can develop. Experience, the role of the nurse, uncertainty and conflict all exert major influences on the decision making process. The conditions that determine what type of decision making pattern emerges are; the seriousness of the risks as a result of the decision; if there is hope of finding a better solution; and how much time is available to search for the solution. The patterns that may emerge include vigilance, complacency, defensive avoidance and hypervigilance. Vigilance is said to be the optimum pattern, this is when all alternatives to the decision are analysed and interpreted in an unbiased manner. Defensive avoidance is the decision makers attempt to avoid or postpone the stress of the decision. It is manifested by procrastination, shifting of responsibility or rationalisation. Hypervigilance, or panic, represents a frantic search for a solution and a shifting back and forth between alternatives with a failure to see obvious faults in the possible solutions.

Conflict, Psychological↗
PubMed1990

Bone loss and age-related fractures.

The aging of the skeleton represents an important cause of both morbidity and mortality in the Western World. A great deal is known about the epidemiology, pathogenesis, and structural alterations which occur during the osteoporotic process to increase the risk of fracture with age. Whereas osteoporosis is associated with a decrease in bone mass, factors other than bone mass are clearly important. These include the turnover of bone and the destruction of trabecular elements, the repair of fatigue damage, as well as extraskeletal factors. An improved understanding of the aging of bones will form a basis for improved strategies for its prevention and treatment.

Age Factors↗
PubMed1990

Communication within low income families and the management of asthma.

This study examines the effects of communication between low income urban parents and children about a chronic disease on the extent to which parent and child effectively manage the illness. Four asthma communication factors were identified by principal component analysis. We found that mothers whose preferred language was Spanish, and families who were not receiving public assistance, communicated more frequently about asthma in general. Spanish speaking mothers and their children communicated more about potential home treatments for asthma, and the more adults in the household the less there was communication about the need for emergency services for asthma. Mothers who preferred to speak Spanish had higher levels of management of the most recent asthma attack. Those whose children communicated with them about asthma in general were higher level managers. Children who influenced their parents' decisions about school attendance, and those whose mothers were more highly educated, had higher levels of asthma attack management. More educated mothers, ones whose children were younger at the time of the onset of asthma, and one who received public assistance, were more involved "in general" in their child's asthma care.

Adult↗
PubMed1990

Hypertensive exercise responses in ciclosporin-treated normotensive renal transplant recipients.

Although many patients taking ciclosporin (CS) for the long term develop hypertensive side effects, a proportion do not. We have studied the blood pressure response to graded upright bicycle exercise while continuously recording the metabolic rate in 18 normotensive renal transplant recipients whose mean age was 30.8 years (range 16-54). Nine were treated with CS alone and 9 with azathioprine and a steroid, prednisolone (AzS). Both groups performed a progressive exercise test, with work increasing by 25 W every 4 min from rest. All patients completed a workload of at least 75 W during the test. A group of 8 normal subjects whose mean age was 29 years (range 19-44) were exercised with the same protocol. The CS group had a significantly higher mean systemic blood pressure at both 50 and 75 W (124 and 132 mm Hg, respectively), compared with the AzS group (103 and 108 mm Hg; p less than 0.01). The blood pressure response to exercise in the AzS group was similar to that observed in the normal group. This was despite a higher metabolic rate at each stage of work in the AzS group as compared with the CS or normal groups. Despite being normotensive at rest, renal transplant patients who are treated with CS have evidence of a vasopressor effect, with systemic vascular resistance inappropriately high for exercise, implying reduced compliance of the vascular bed.

Adolescent↗
PubMed1990

Production of tumor necrosis factor by human osteoblasts is modulated by other cytokines, but not by osteotropic hormones.

Human osteoblast cultures derived as out-growths from trabecular bone released tumor necrosis factor (TNF alpha) upon stimulation of the cells with human recombinant interleukin 1 (IL1; 10(-13)-10(-11) M), human recombinant granulocyte-macrophage colony-stimulating factor (100-1000 U/ml), and bacterial lipopolysaccharide (5-500 ng/ml). The osteotropic hormones 1,25-dihydroxyvitamin D3, PTH, and calcitonin had no effect on TNF production. The TNF released by the osteoblasts was identified as TNF alpha, using a specific anti-TNF alpha monoclonal antibody to neutralize its activity. Immunohistochemical staining of the cells using the same antibody revealed that all of the cells in the cultures were capable of producing TNF alpha, including those that also expressed alkaline phosphatase activity. Immunoreactive protein could be detected in the perinuclear region when cells were cultured in the presence of monensin, suggesting accumulation of newly synthesised protein in the Golgi apparatus. These results suggest that human osteoblasts, which have been shown previously to respond to TNF alpha, can synthesize and release TNF in response to IL1 and granulocyte-macrophage colony-stimulating factor. TNF may, therefore, not only have a pathological role in conditions of chronic inflammation, but also may act as a local paracrine or autocrine regulator of osteoblast function.

Calcitonin↗
PubMed1990

Cerebral blood flow velocity recordings and the prediction of intracranial haemorrhage and ischaemia.

Doppler ultrasound was used to study prospectively cerebral and cardiovascular hemodynamics in a cohort of 120 preterm infants to see whether it was possible to predict infants at increased risk of developing cerebral pathology. The infants were divided into four outcome groups: Group I (n = 65, median gestation = 30 weeks) did not develop periventricular haemorrhage (PVH) nor periventricular leukomalacia (PVL) Group II (n = 43, median gestation = 28 weeks) developed PVH as the first or only cerebral lesion Group III (n = 7, median gestation = 29 weeks) developed PVL as the first or only cerebral lesion Group IV (n = 5, median gestation = 28 weeks) developed PVH and PVL simultaneously. Cerebral blood flow velocity (CBFV) and aorta blood flow velocity (ABFV) recordings made before the onset of PVH or PVL were compared between the four groups on each postnatal day but it was not possible to demonstrate a statistically significant difference between these variables in the four outcome groups. We conclude, therefore, that it is not possible to identify the infants who will go on to develop haemorrhage or ischaemic lesions on the basis of Doppler cerebral haemodynamic studies.

Aorta↗
PubMed1989

The disposition of meptazinol after single and multiple intravenous administration to pregnant and non-pregnant women.

We have studied the disposition of the centrally-acting analgesic meptazinol in a group of age-matched non-pregnant and pregnant (36-38 weeks gestation) women. Ten non-pregnant and nine multiparous pregnant volunteers each received a single i.v. dose of meptazinol hydrochloride (equivalent to 25 mg base). A further group of 9 non-pregnant (including four of the original participants) and 10 multiparous pregnant subjects were given repeated i.v. doses of meptazinol hydrochloride (each equivalent to 10 mg base) at 30-min intervals for 2.5 h. Meptazinol plasma concentrations were determined by HPLC using fluorescence detection and the pharmacokinetic variables investigated. After single dosing there were no statistical differences in half-life, clearance, or apparent volume of distribution between the two groups, suggesting that the disposition of meptazinol was not altered by pregnancy. This was confirmed in the repeated dose study, in which no significant differences occurred in either the plasma concentrations achieved or in areas under the curves between the non-pregnant and pregnant subjects. Furthermore, the steady-state concentrations were comparable with those predicted from the single dose results. This indicates that there should be no requirement for dosage alteration of meptazinol during pregnancy.

Adult↗
PubMed1989

Identification of the initiation codons for translation of cowpea mosaic virus middle component RNA using site-directed mutagenesis of an infectious cDNA clone.

A full-length cDNA copy of CPMV M RNA has been cloned downstream of a phage lambda promoter in the plasmid pPMI. Transcripts obtained from this clone can be translated in vitro and replicated in cowpea mesophyll protoplasts in the presence of viral B RNA. We have constructed a series of site-directed mutants of this clone to investigate the mechanism of translation of CPMV M RNA. The results obtained confirm that the AUG at position 161 is used to direct the synthesis of a 105K protein in vitro and the detection of a 58K protein in infected cowpea protoplasts suggests that it is also used in vivo. The synthesis of the 95K protein can be initiated from either of the AUGs at positions 512 and 524, though synthesis of this protein does not appear to be essential for CPMV replication in protoplasts.

Blotting, Northern↗
PubMed1989

Chest wall pain after aortocoronary bypass surgery using internal mammary artery graft: a new pain syndrome?

During an 18-month period 11 patients were seen at the Toronto Western Hospital Pain Clinic 4 months to 5 years after internal mammary artery (IMA) bypass with a specific cluster of chest wall symptoms and signs confined to the site of IMA graft harvesting. Sympathetic ganglia blocks produced dramatic but temporary relief of symptoms in two of the most severely affected patients. In two other patients seen quite early after surgery, use of transcutaneous electrical stimulation produced considerable and permanent decrease of symptoms within 3 weeks. Such a chronic pain syndrome has not been previously reported in the literature. We postulate that IMA bypass surgery may be associated with a specific pain syndrome. This syndrome may arise from injury to the anterior branches of the intercostal nerves at the site of graft harvesting. Possible neurophysiologic mechanisms are discussed.

Aged↗