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Biomedical subjects

A McKay

Publications and source records attributed to A McKay.

16 recordsLinked to original sources
PubMed2006

Meta-analysis of pancreaticojejunostomy versus pancreaticogastrostomy reconstruction after pancreaticoduodenectomy.

BACKGROUND: Pancreaticoduodenectomy is the primary treatment for periampullary cancer. Associated morbidity is high and often related to pancreatic anastomotic failure. This paper compares rates of pancreatic fistula, morbidity and mortality after pancreaticoduodenectomy in patients having reconstruction by pancreaticogastrostomy with those in patients having reconstruction by pancreaticojejunostomy. METHODS: A meta-analysis was performed of all large cohort and randomized controlled trials carried out since 1990. RESULTS: Eleven articles were identified for inclusion: one prospective randomized trial, two non-randomized prospective trials and eight observational cohort studies. The meta-analysis revealed a higher rate of pancreatic fistula associated with pancreaticojejunostomy reconstruction (relative risk (RR) 2.62 (95 per cent confidence interval (c.i.) 1.91 to 3.60)). A higher overall morbidity rate was also demonstrated in this group (RR 1.43 (95 per cent c.i. 1.26 to 1.61)), as was a higher mortality rate (RR 2.51 (95 per cent c.i. 1.61 to 3.91)). CONCLUSION: Current literature suggests that the safer means of pancreatic reconstruction after pancreaticoduodenectomy is pancreaticogastrostomy, but much of the evidence comes from observational cohort study data.

Ampulla of Vater↗
PubMed2006

Current role of radiofrequency ablation for the treatment of colorectal liver metastases.

BACKGROUND AND METHOD: This paper reviews the current status of radiofrequency ablation in the treatment of colorectal liver metastases. Relevant studies with at least ten patients that reported rates of complete tumour ablation, local recurrence, or survival from 1 to 5 years after treatment were included in the review. RESULTS AND CONCLUSION: Only six studies that reported at least 3-year survival were identified, with results ranging from 37 to 58 per cent. Some of these figures are promising, given that the patients were considered to have unresectable disease. However, available evidence is limited and hepatic resection remains the standard of care when feasible; radiofrequency ablation cannot be considered an equivalent. Radiofrequency ablation does, however, appear to have a role in treating unresectable disease, and may also be used in conjunction with resection to extend its limits.

Catheter Ablation↗
PubMed2004

Interleukin-18 levels in induced sputum are reduced in asthmatic and normal smokers.

BACKGROUND: IL-18 is a cytokine which is known to have an important role in the development of a Th1 lymphocyte response. As such, it may have a regulatory role in asthma by modifying Th2 lymphocyte responses. Cigarette smoking may amplify the airway inflammation associated with asthma. OBJECTIVE: This study investigated if IL-18 could be detected in induced sputum from asthmatics and normal subjects and if smoking altered IL-18 levels. METHODS: Induced sputum was obtained from asthmatic (31 smokers, 35 non-smokers) and normal (20 smokers, 20 non-smokers) subjects. All smokers had a smoking history of > or =15 pack years. IL-18 levels in sputum supernatant were measured by ELISA. IL-18 mRNA expression and cellular localization were assessed by quantitative PCR and immunocytochemistry, respectively. RESULTS: Smoking was associated with a significant reduction in IL-18 levels (median (interquartile range) - smokers 20 (0-102) pg/mL vs. non-smokers 358 (50-876) pg/mL, P<0.001). This was more pronounced in asthmatics (smokers, 47 (40-64) pg/mL vs. non-smokers, 530 (30-1484) pg/mL; P<0.001) than in normal subjects (smokers, 25 (0-78) pg/mL vs. non-smokers, 247 (50-656) pg/mL; P<0.01). Within each of the smoking and non-smoking groups there was no significant difference in IL-18 levels between asthmatic and normal subjects. There was no correlation between sputum IL-18 levels and any specific cell type in the sputum samples nor serum IgE levels. IL-18 mRNA expression was reduced in asthmatic smokers compared with non-smokers. IL-18 production was localized to sputum macrophages by immunocytochemistry. CONCLUSIONS: IL-18 is detectable in induced sputum samples from both asthmatic and normal subjects. Cigarette smoking significantly reduces sputum IL-18 levels. This effect is more pronounced in asthmatics than in normal subjects.

Adult↗
PubMed2001

Immuno-regulatory cytokines in asthma: IL-15 and IL-13 in induced sputum.

BACKGROUND: The importance of Th2-type lymphocyte function in asthmatic airway inflammation is well recognized, but less is known about the factors which regulate the function of these lymphocytes in asthma. The macrophage-derived cytokine, interleukin (IL)-15 has a number of T cell regulatory properties which might be of relevance to asthma and its treatment. OBJECTIVE: The aims were to identify and quantify the T cell regulatory cytokine IL-15 in induced sputum samples from asthmatic patients, in comparison with IL-13, and to relate the levels of these cytokines to treatment with inhaled steroids. METHODS: Induced sputum was collected from 16 asthmatics (eight steroid and eight non-steroid treated) and eight normal controls. IL-15 and IL-13 levels were measured by enzyme-linked immunoassay (ELISA) in sputum. IL-15 levels were also measured in sputum cell culture supernatants and localized to specific sputum cells by immuno-cytochemistry. RESULTS: IL-15 levels were increased and IL-13 levels were decreased in sputum fluid from steroid-treated compared with non-steroid-treated asthmatics. IL-15 was localized specifically to macrophages and the proportion of these cells expressing IL-15 correlated with sputum fluid IL-15 and IL-15 levels in cell culture supernatants, and all were higher in the steroid-treated asthmatics. CONCLUSION: IL-15 and IL-13 production appears to be reciprocally regulated by steroid therapy in asthma patients. The steroid-associated increase in IL-15 may regulate a fundamental shift away from an inflammatory Th2-type environment in asthma and may be an essential component of the cytokine modulation underlying the therapeutic benefit of corticosteroids in this condition.

Adult↗
PubMed1997

Glucose modification of human serum albumin: a structural study.

Structural changes associated with the exposure of human serum albumin (HSA) to glucose with or without the presence of Cu (II) have been characterized using a bank of methods for structural analysis including circular dichroism (CD), amino acid analysis (AAA), fluorescence measurements, SDS-PAGE, and boronate binding (which is a measure of Amadori product formation). We show that in the short-term (10 d) incubation mixtures, HSA is resistant to Cu (II)-mediated oxidative damage and that the early products of glycation of HSA had minimal effects on the folded structure. Amino acid analysis showed that there was no formation of advanced glycation endproducts (AGE), which can be measured by loss of lysine. This remained the case in longer term incubation of HSA (56 d) in the hyperglycemic concentration range (5-25 mM glucose) despite increased levels of Amadori product (60% boronate binding) and the formation of glycophore (Excitation 350, Emission 425). At high, nonphysiological concentrations (100 mM and 500 mM) of glucose, glycophore formation increased and 3 and 11 mol Lysine-glucose adduct/mol HSA were converted to AGE, respectively. This was accompanied by increased damage to tryptophan and protein-protein crosslinking but only minor tertiary structural change. In the presence of Cu (II), however, AGE formation was accompanied by extensive damage to histidine and tryptophan side chains, main chain fragmentation, and loss of both secondary and tertiary structure. Thus, changes in structure appear to be the result of oxidation as opposed to glycation, per se.

Amino Acids↗
PubMed1995

Comparison of left and right vertebral artery intracranial diameters.

BACKGROUND: The vertebral artery is vulnerable to mechanical injury, especially in the region of the first and second cervical vertebrae, with resultant thrombus and/or emboli formation, often found at the vertebro-basilar junction. Such vascular injuries and associated neurological insults have been documented repeatedly in the literature as following cervical spine manipulation, when movements of the head and neck can cause compression and/or stretching of the vertebral artery and alterations in its blood flow. This has particular clinical relevance if a patient has a hypoplastic vertebral artery. Such persons may be considered at risk as regards vascular accidents following manipulation of the cervical spine. The aim of this study was to measure and compare the intracranial diameters of the left and right vertebral arteries in groups of black and white male and female South African subjects. METHODS: Cadaver material from 58 specimens was processed for light microscopy, and measurements of inner (lumen only) and outer (lumen, tunica intima, and tunica media) diameters taken and compared, using the t-test. RESULTS: Data analysis revealed a significant difference between the left and right vertebral artery intracranial diameters in the white female group only (N = 8). CONCLUSIONS: Such a statistically significant difference implies a difference of biological importance and it is suggested that this particular group of subjects may be a high-risk group as regards vascular accidents following cervical spine manipulation.

Black People↗
PubMed1991

The effects of ethylenediamine in the rat small intestine: a powerful relaxant of the muscularis.

The pharmacology of ethylenediamine (EDA) actions in the rat small intestine was examined using isolated gut-bath preparations of proximal segments of the duodenum, jejunum, and ileum. EDA evoked concentration-dependent tetrodotoxin-insensitive relaxations of the intestine, evidently by direct action on the muscularis. Such actions were simultaneous on the longitudinal and circular muscle layers. Investigation of EDA actions on the circular muscle showed that EDA actions were unrelated to any intrinsic GABAergic mechanisms. Moreover, EDA interacted with muscle sites distinct from ATP, histamine, bradykinin, muscarinic, and adrenergic receptors. The ability of EDA to relax the intestinal musculature was generally greater than the smooth muscle relaxant papaverine and substantially better than nicotinic stimulation of the intrinsic inhibitory neurones. It would appear that EDA may be useful as a direct acting smooth muscle relaxant for the study of the physiology-pharmacology of the rodent small intestine.

Adrenergic alpha-Antagonists↗
PubMed1990

Differences in the effects (in vitro) of ethylenediamine on the guinea-pig and rat intestine.

The effects of ethylenediamine in different regions of the rat and guinea-pig small intestine were investigated pharmacologically using isolated gut-bath preparations. In the guinea-pig, ethylenediamine caused concentration-dependent neurally mediated contractions or biphasic responses (contraction followed by relaxation). The contractions could be prevented by muscarinic and GABAA receptor antagonists. Ethylenediamine-evoked relaxations and depression of electrically evoked cholinergic twitch responses were blocked by desensitization to baclofen. However, in the rat intestine, the primary response to applied ethylenediamine was a concentration-dependent, non-desensitizing relaxation, evidently due to a direct action of ethylenediamine on the muscularis since it was unaffected by tetrodotoxin or GABAergic blockade.

Animals↗
PubMed1983

Epoprostenol (prostacyclin) and severe arterial disease. A double-blind trial.

A 96 h infusion of epoprostenol (prostacyclin) or placebo was given as a treatment for rest pain to 28 patients with severe peripheral arterial disease. 24 h after the end of the infusion patients given epoprostenol had significantly less pain and took fewer analgesics tablets than did the controls. In some patients the epoprostenol effect lasted for over 1 month.

Arterial Occlusive Diseases↗
PubMed1978

Improving cognitive ability in chronically deprived children.

Beginning at different ages in their preschool years, groups of chronically undernourished children from Colombian families of low socioeconomic status participated in a program of treatment combining nutritional, health care, and educational features. By school age the gap in cognitive ability between the treated children and a group of privileged children in the same city had narrowed, the effect being greater the younger the children were when they entered the treatment program. The gains were still evident at the end of the first grade in primary school, a year after the experiment had ended.

Age Factors↗