Search PubMed⌕ Search

Biomedical subjects

J Burns

Publications and source records attributed to J Burns.

At least 37 records · Page 2Linked to original sources
PubMed2001

Age related changes in the tunica media of the vertebral artery: implications for the assessment of vessels injured by trauma.

AIMS: To provide an illustrated, detailed semiquantitative analysis of the important degenerative changes along the length of the vertebral artery so that pathologists faced with investigating a fatal arterial injury can identify important pre-existing wall abnormalities. METHODS: Ten transverse annuli were taken along 34 vertebral arteries from 17 subjects and stained sections were prepared using haematoxylin and eosin and the picro-sirius red method. After routine microscopy, the elastic fibres, collagen, and smooth muscle nuclei in the tunica media were quantified using an eyepiece graticule. An estimate of the severity and extent of elastic tissue fragmentation, collagenous scarring, and intimal thickening/atheroma was then undertaken. RESULTS: Smooth muscle counts remained constant along the artery but collagen counts were higher and elastic counts substantially lower within the intracranial segment. Elastic fibre fragmentation was recognised in infancy and was moderately advanced by early adulthood but considerable collagenous scarring developed later in life. Some individuals demonstrated severe fragmentation and scarring before the age of 35 years. The degenerative changes were often focal and spared the intracranial segment almost completely. Atheroma increased with age but was rarely severe and appeared not to worsen appreciably beyond the age of 40 years. An unusual arrangement of the collagenous tissue was described within the upper cervical loops. CONCLUSION: Damaged vertebral arteries need to be sampled extensively to allow a proper histological assessment. The picro-sirius red method was successful in delineating the fine connective tissue structure of the wall and early degenerative changes. An understanding of the age and site specific changes should allow the pathologist to recognise important pre-existing abnormalities more easily.

Adolescent↗
PubMed2001

Myelodysplastic syndromes: a community hospital-based study of prognostic factors and International Prognostic Scoring System.

Various prognostic factors and the International Prognosis Scoring System (IPSS) were assessed in our community hospital-based retrospective study of 55 cases of myelodysplastic syndromes (MDS). All cases were reviewed for clinical, hematologic, histopathologic, and cytogenetic data. The median follow-up was 1.61 years. Twenty patients (36%) were classified as refractory anemia (RA); seven (13%) as refractory anemia with ringed sideroblasts (RARS); 13 (24%) as chronic myelomonocytic leukemia (CMML); 11 (20%) as refractory anemia with excess blasts (RAEB); and four (7%) as refractory anemia with excess blasts in transformation (RAEB-t). Twenty-seven (49%) died during the follow-up period, seven with acute myelogenous leukemia (AML). The median survival was 2.8 years. The variables that showed association with survival by univariate analysis included the absolute neutrophil count, French-American-British (FAB) subtype, percentage of blasts, number of cytopenias, abnormal localization of immature precursors, and IPSS score. When entered into a regression model, IPSS showed a trend towards an association with survival (P 0.09). We conclude that the IPSS can prognostically stratify MDS patients. However, no independent prognostic factor was confirmed in our analysis. Further studies are needed to assess the utility of IPSS.

Aged↗
PubMed2001

Alcohol consumption and mortality: is wine different from other alcoholic beverages?

BACKGROUND: Alcohol has been an integral part of the diets of many cultures for thousands of years, and formed the basis of early antiseptics. However, many health professionals have been loath to recommend its moderate consumption. Fears of increased risks of cancers, strokes and coronary heart disease (CHD), as well as its role in accidents, violence, psychological and social decline (when consumed in excess) meant that alcohol was viewed as generally detrimental to health. Recent reports have examined some of these fears and suggest that the moderate consumption of alcoholic beverages, particularly red wine, may actually protect against the development of CHD. Evidence for the influence of alcoholic drinks on strokes and cancer is less clear. OBJECTIVES: This review discusses the chemical differences between red wine and other alcoholic beverages and their possible effects on the development of CHD, stroke and cancer. DATA SYNTHESIS AND CONCLUSIONS: Both clinical and experimental evidence suggest that red wine does indeed offer a greater protection to health than other alcoholic beverages. This protection has been attributed to grape-derived antioxidant polyphenolic compounds found particularly in red wine.

Alcohol Drinking↗
PubMed2000

A biomechanical study of the human vertebral artery with implications for fatal arterial injury.

We studied the biomechanical behaviour of ring and strip specimens from along the length of 18 vertebral arteries taken from 16 subjects aged 28-90 years, in order to consider some of the factors which may play a role in vertebral artery rupture. The method was chosen to allow a comparison between circumferential distension (ring samples) and longitudinal extension, (strip samples). The samples were extended between the jaws of a tensile testing apparatus until the specimen broke and a number of biomechanical parameters were derived. These were the percentage extension to break, the tensile strength, Young's modulus and the peak load. There were a number of important findings. The vertebral artery was shown to be susceptible to longitudinal stretching with a number of strip samples breaking when extended by as little as 16-20%. The tensile strength and load at peak of the strip specimens were correspondingly lower than for the ring samples. Marked intersubject variations were shown for all these parameters and prominent changes in behaviour occurred along the vertebral artery. This study indicates that the artery may be susceptible to head and neck movements which cause the vessel to stretch, and intersubject variations in behaviour may be one important explanation for the marked differences in outcome which appear to exist in subjects who suffer broadly similar head and neck insults.

Adult↗
PubMed2000

Autopsy consent practice at US teaching hospitals: results of a national survey.

BACKGROUND: Autopsy rates continue to fall despite the enduring benefit of the procedure to families and medical science, yet there are few data about the consent process itself. OBJECTIVE: To evaluate the current practice of obtaining autopsy consent, by assessing the consent forms currently in use, the knowledge and attitudes of chief residents on the procedure, and the expert opinion of pathologists in those institutions. DESIGN: Cross-sectional survey. SETTINGS AND PARTICIPANTS: One hundred twenty-seven US teaching hospitals. RESULTS: Of all autopsy consent forms we surveyed, 84.7% contained 7 of 10 elements recommended by the College of American Pathologists. Only 7.1% of institutions supplied educational materials for the physician, as recommended by the College of American Pathologists. Overall, 50.1% of chief residents reported deficiencies in their knowledge of the autopsy procedure. Correspondingly, greater than 74.5% felt that educational materials would be beneficial for physicians and the family. Finally, 93.3% of chief residents believed that a limited autopsy should be offered to families, while 68 (90%) of 76 pathologists at these institutions believed that limited autopsies are an unsatisfactory alternative to the complete procedure. CONCLUSIONS: Chief residents at US teaching hospitals reported substantial deficiencies in their knowledge about autopsy and desire more training on the consent process. Autopsy consent forms are often lacking information that might help physicians and families in making an educated choice about autopsy. Teaching institutions need to reevaluate the training for the autopsy consent practice.

Autopsy↗
PubMed2000

Age, stability of the precorneal tear film and the refractive index of tears.

PURPOSE: To investigate the relationship between age, stability of the precorneal tear film and refractive index of tear samples drawn from a normal population. METHODS: The stability of the precorneal tear film was estimated by measuring the Tear Thinning Time MT) using the Bausch and Lomb keratometer. Microlitre tear samples were obtained from the lower tear meniscus using glass capillary tubes. The refractive index (RI) was measured using a digital electronic Abbe refractometer with an accuracy of +/- 0.00005 units. Measurements were obtained from the right eyes of 110 subjects (55 male and 55 female) ranging in age from 18 to 89 years. They were all healthy, non-contact lens wearing individuals with no history of ocular disease or dry eye symptoms. RESULTS: A significant relationship was found between age (x) and tear stability (TTT) in both genders. Females, TTT = 32.89-0.33x, (Spearman correlation coefficient, r = -0.537, P = 0.0001). Males, TTT = 29.25-0.29x (Spearman correlation coefficient, r = -0.353, P = 0.008). A significant correlation was found between age (x) and refractive index (RI) in females only RI = 1.33815-0.000023x, (Spearman correlation coefficient, r = -0.299, P = 0.027). CONCLUSION: Tear stability is lower in the aged eye regardless of gender. Tear refractive index is lower in the older female eye.

Journal Article↗
PubMed2000

Relationship among antioxidant activity, vasodilation capacity, and phenolic content of red wines.

The relationship among antioxidant activity, based on the electron-spin resonance determination of the reduction of Fremy's radical, vasodilation activity, and phenolic content was investigated in 16 red wines. The wines were selected to provide a range of origins, grape varieties, and vinification methods. Sensitive and selective HPLC methods were used for the analysis of the major phenolics in red wine: free and conjugated myricetin, quercetin, kaempferol, and isorhamnetin; (+)-catechin, (-)-epicatechin, gallic acid, p-coumaric acid, caffeic acid, caftaric acid, trans-resveratrol, cis-resveratrol, and trans-resveratrol glucoside. Total anthocyanins were measured using a colorimetric assay. The total phenolic content of the wines was determined according to the Folin-Ciocalteu colorimetric assay and also by the cumulative measurements obtained by HPLC. The 16 wines exhibited a wide range in the values of all parameters investigated. However, the total phenol contents, measured both by HPLC and colorimetrically, correlated very strongly with the antioxidant activity and vasodilation activity. In addition, the antioxidant activity was associated with gallic acid, total resveratrol, and total catechin. In contrast, only the total anthocyanins were correlated with vasodilation activity. The results demonstrate that the different phenolic profiles of wines can produce varying antioxidant and vasodilatant activities, which opens up the possibility that some red wines may provide enhanced health benefits for the consumer.

Antioxidants↗
PubMed2000

Prediction of dietary flavonol consumption from fasting plasma concentration or urinary excretion.

OBJECTIVES: to predict flavonols content of the habitual diets of free-living subjects from urine and plasma concentrations of flavonols. DESIGN: Ten type 2 diabetic patients (five male, five female), mean age 60 (s.e.m. 7) y and BMI 30.2 (s.e.m. 3.5) kg/m2 were treated in a random crossover design for a 2 week period on either a low flavonoid diet or on the same diet supplemented at one of two high flavonols levels (total 77.3 or 110.4 mg/day) provided by supplements of 1500 ml tea daily and 400 g fried white onion in olive oil with and without tomato ketchup and herbs. SETTING: Glasgow Royal Infirmary, University of Glasgow, Scotland. MAIN OUTCOME MEASURES: Fasting plasma concentration, urine concentration and 24 h excretion of quercetin, isorhamnetin, kaempferol and myricetin. RESULTS: Plasma flavonol concentration (r=0.750, P=0.001), 24 h urine concentration (r=0.847, P=0.001) and 24 h urine excretion (r=0.728, P=<0.001) were all highly significantly related to dietary intake and gave similar estimates of intakes. Fasting plasma flavonols concentrations on habitual diets ranged from 0 to 43.7 ng/ml mean. Regression equations were constricted: total flavonols intake r=0.74, P<0.001 and quercetin intake r=0.744, P<0. 001. From these equations, flavonol intakes from habitual diets were estimated at 17-50, mean 35 mg/day. Of this, 91% was from quercetin. CONCLUSIONS: Dietary flavonols are absorbed and appear in plasma and urine as potential biomarkers in concentrations related quantitatively to intake. Estimation of dietary intake from plasma or urine concentrations appears possible. SPONSORSHIP: Rank Prize Funds and Rank Foundation of the Department of Human Nutrition; Ministry of Health and Medical Education, IR Iran. European Journal of Clinical Nutrition (2000) 54, 143-149

Aged↗
PubMed2000

The measurement of locus of control: assessing more than meets the eye?

Ambiguities in the conceptions and measurement of locus of control were investigated in this study. Specifically, some psychometric properties of several widely used measures of perceived behavior-outcome contingency, interpersonal power, and social self-efficacy were assessed. To different degrees, the results indicated that all three measures of perceived behavior-outcome contingency lacked convergent and discriminant validity. Implications for interpreting past research, directions for future investigations, and limitations of the present study are discussed.

Adolescent↗
PubMed2000

Postoperative evaluation of patients following ophthalmic surgery.

We have used telemedicine to support the postoperative evaluation of patients who have had ophthalmic surgery. Mobile telemedicine workstations connected using three ISDN lines have enabled us to review patients at an outreach clinic on the first postoperative day. Video slit-lamp images of the patient are captured by a trained ophthalmic nurse at the outreach clinic and viewed by surgeons at Moorfields Eye Hospital in central London during live teleconsultations. During the study period, over 80 teleconsultations were carried out on postoperative cataract, trabeculectomy and combined procedures. Preliminary results are very encouraging. Although 8 (33%) of 24 patients were anxious about being involved in the teleconsultation, 20 (83%) had confidence in the system and only one (4%) found the experience unacceptable.

Eye Diseases↗
PubMed2000

Antioxidant flavonols from fruits, vegetables and beverages: measurements and bioavailability.

Flavonols are polyphenolic secondary plant metabolites that are present in varying levels in commonly consumed fruits, vegetables and beverages. Flavonols have long held an interest for nutritionists, which has increased following a Dutch study in the early 1990's showing that dietary intake of flavonols was inversely correlated with the incidence of coronary heart disease. The main factors that have hindered workers in the field of flavonol research are (i) the accurate measurement of these compounds in foods and biological samples, and (ii) a dearth of information on their absorption and metabolism. This review aims to highlight the work of the authors in attempting to clarify the situation. The sensitive and selective HPLC procedure to identify and quantify common flavonols and their sugar conjugates is described. In addition, the results of an on-going screening program into the flavonol content of common produce and beverages are presented. The bioavailability of dietary flavonols is discussed with reference to an intervention study with onions, as well as pilot studies with tea, red wine and cherry tomatoes. It is concluded that flavonols are absorbable and accumulate in plasma and that consuming high flavonol-containing varieties of fruits and vegetables and particular types of beverages could increase their circulatory levels.

Antioxidants↗