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Biomedical subjects

M Jackson

Publications and source records attributed to M Jackson.

At least 37 records · Page 2Linked to original sources
PubMed2004

Troponin T: how high is high? Relationship and differences between serum cardiac markers according to level of creatine kinase and type of myocardial infarction.

Cardiac troponins have emerged over recent years as the "gold standard" serum biochemical marker for the diagnosis and management for patients with acute myocardial infarction (MI). The relationship between old (creatine kinase; CK) and new (troponin T; TT) markers of myocardial injury were examined in this study of 392 consecutive patients admitted to a district hospital with a diagnosis of an acute MI. Significant correlation of serum TT and peak CK levels were seen (R = 0.58, p<0.0001) in all types of MI. A significant relationship was also seen according to type of MI (Q wave or non-Q wave MI) or peak CK level. The regression equation (TT (microg/l) = 0.0027 (peak CK) + 1.1160 (IU/l)) may be used by clinicians to estimate TT release from a known peak CK result and thus provide some guidance on equivalence between the two tests. Our findings provide physicians with a benchmark reference range between the two cardiac markers, according to level of peak CK.

Adult↗
PubMed2003

Predicting blood pressure reactivity and heart rate variability from mood state following coronary artery bypass surgery.

STUDY OBJECTIVES: Coronary Artery Bypass Graft (CABG) surgery is a common and successful procedure for revascularisation. However, the experience can induce emotional reactions prior to and following surgery. This study aimed to document changes in blood pressure (BP) reactivity and heart rate variability (HRV) following CABG surgery, and to determine the impact of mood state, particularly anxiety and depression upon cardiovascular functioning. METHOD: Twenty-two patients preparing to receive elective, first time CABG surgery were recruited from The Cardiothoracic Centre, Liverpool, UK and psychologically assessed using the Hospital Anxiety and Depression Scale (HAD), Global Mood Scale (GMS) and the Dispositional Resilience Scale (DRI). BP and heart rate responses were also measured during four conditions: baseline response; laboratory session; ambulatory monitoring; and self-initialised recordings during the ambulatory period. In addition, HRV was measured for 12 h in conjunction with the ambulatory monitoring period. All measures were assessed 1 week prior to surgery and 2 months following surgery. RESULTS: A significant decrease in negative mood and an increase in positive mood were reported following surgery. Forty percent of patients were clinically anxious and depressed prior to surgery although this was reduced to 27% after surgery. Depression was the strongest independent predictor of pre-operative BP and HRV whilst anxiety was most significantly related to follow-up BP reactivity. DBP was most strongly predicted by mood state. CONCLUSIONS: These results suggest that patients with higher levels of anxiety and depression are at risk of reduced HRV and increased BP reactivity in response to mental stressors. The study also strongly suggests that current patient services should be expanded to acknowledge the role of psychological factors within clinical prognosis after CABG surgery.

Affect↗
PubMed2003

Social and dietary determinants of body mass index of adult Jamaicans of African origin.

OBJECTIVES: To determine the relationships between body mass index (BMI) and diet, social and behavioural factors among adult Jamaicans of African origin. DESIGN: Cross-sectional. SETTING: Urban communities in Jamaica, West Indies. SUBJECTS: Three-hundred and sixty-three males and 561 females of African origin, aged 25-74 y. RESULTS: Women had higher mean BMIs (27.5+/-6.4 kg/m(2)) than men (23.4+/-4.3 kg/m(2)); 30.7% of women compared with 6.7% of men were obese. There was a tendency for obese men to have higher percentage of intakes from fat and less from carbohydrate, and women reported diets in which the percentage contribution of protein increased significantly with increasing BMI. In multivariate analyses, BMI was not explained by energy but was associated with protein intakes in females only. Predictors of relative weight were inversely related. Social (marital status) and behavioural (cigarette smoking) factors predicted BMI in both genders; older age in men and increased fibre intakes in women were associated with lower BMI. CONCLUSIONS: Social and behavioural factors are important determinants of body weight. Further investigations are needed which consider factors such as physical activity, genetic and other environmental variables as predictors of relative weight.

Adult↗
PubMed2003

Monitoring blood transfusion in patients undergoing coronary artery bypass grafting: an audit methodology.

BACKGROUND AND OBJECTIVES: The purpose of this work was to describe the methodology used to build a transfusion database that allows continuous audit of transfusion practices in coronary artery bypass surgery. MATERIALS AND METHODS: The transfusion database requires electronic data available from two sources: the hospital's patient administration system; and the local blood transfusion service. RESULTS: We demonstrated a reduction in the percentage of patients receiving red blood cell transfusion: from 47.4% in 1997/1998 to 31.6% in 2001/2002 (P<0.001). Reductions have also been shown in the percentage of patients receiving fresh-frozen plasma and platelet units. CONCLUSIONS: The data sourcing the transfusion database should be available to all hospitals through their patient administration systems and local blood transfusion service. Its use can help to reduce transfusion rates significantly.

Blood Transfusion↗
PubMed2003

Diving beetles (Dytiscidae) as predators of mosquito larvae (Culicidae) in field experiments and in laboratory tests of prey preference.

Field experiments were performed in artificial ponds to evaluate how the density of predatory diving beetles (Dytiscidae) would affect the population levels of mosquito larvae (Culicidae). Mosquitoes colonizing the ponds were predominantly species of the genus Culex. In 2000, most of the dytiscids colonizing the ponds were small (Hydroporus spp.), and these predators had no impact on the size of larval mosquito populations, not even in ponds with added dytiscids. In 2001, larger beetles (Ilybius, Rhantus, and Agabus spp.) were more common, and there were significantly fewer mosquito larvae in ponds with the highest numbers of dytiscids. There was a negative correlation between numbers of diving beetles in the ponds and the mean body length of mosquito larvae. In neither year could dytiscid densities be maintained above a certain level owing to emigration. In laboratory tests, there were marked differences between three common dytiscid species in regard to preferences for Daphnia and Culex species as prey: Colymbetes paykulli Erichson chose mosquito larvae more often, whereas both Ilybius ater (De Geer) and I. fuliginosus (Fabricius) preferred Daphnia spp. All of the tested dytiscids consumed large numbers of prey. Since some dytiscid species can efficiently decrease populations of mosquito larvae, they are probably important in the natural control of these dipterans.

Animals↗
PubMed2003

Infrared spectroscopy: shedding light on synovitis in patients with rheumatoid arthritis.

OBJECTIVES: It is difficult to determine the extent of synovial involvement early in the course of rheumatoid arthritis. A spectroscopic technique was used to characterize the synovium of the small finger joints in both early and late rheumatoid arthritis. This synovium was also compared against normal joints. METHODS: Near-infrared spectroscopy assesses the absorption of near-infrared light by specific joints, giving a characteristic "fingerprint" of the properties of the underlying tissues. Triple measurements by infrared spectroscopy were taken at the bilateral second and third metacarpophalangeal joints. Multivariate analysis was applied. RESULTS: Analysis was able to demonstrate relationships between the specific sources of spectral variation and joint tenderness or swelling as well as radiographic damage. Further use of multivariate analysis allowed recognition of the spectral patterns seen in early disease vs late rheumatoid arthritis and correct classification of over 74% of the joints. CONCLUSIONS: The spectral regions where differences occurred were in the absorption bands related to tissue oxygenation status, allowing the provocative implication that this technique could be detecting ischaemic changes within the joint. Near-infrared spectroscopy may thus be able to provide us with some information about the biochemical changes associated with synovitis.

Arthritis, Rheumatoid↗
PubMed2003

Sanfilippo syndrome type D: identification of the first mutation in the N-acetylglucosamine-6-sulphatase gene.

Mucopolysaccharidosis type IIID is the least common of the four subtypes of Sanfilippo syndrome. It is caused by a deficiency of N-acetylglucosamine-6-sulphatase, which is one of the enzymes involved in the catabolism of heparan sulphate. We present the clinical, biochemical, and, for the first time, the molecular diagnosis of a patient with Sanfilippo D disease. The patient was found to be homozygous for a single base pair deletion (c1169delA), which will cause a frameshift and premature termination of the protein. Accurate carrier detection is now available for other members of this consanguineous family.

Base Sequence↗
PubMed2003

Heart weight and heart weight/body weight ratio in a Jamaican adult autopsy population. A preliminary study.

The heart weight and heart weight/body weight (HW/BW) ratio were assessed in an adult autopsy population and compared with commonly used reference values. Examination of 127 adult post-mortem cases (80 males and 47 females, aged 17 to 91 years) revealed that the mean heart weight and the HW/BW ratios of both genders were significantly greater than the reference values, particularly so in the hypertensive patients. These findings suggest that the Jamaican adult heart is significantly heavier than values used from reference tables. In both genders, heart weight was significantly and positively correlated with body weight and body mass index but not height, for non-hypertensive and hypertensive subjects. The present data are preliminary and not comprehensive enough to establish definitive reference values for the Jamaican population. However, this information needs to be taken into consideration when making pathologic diagnoses using heart weight as a criterion in post-mortem diagnosis.

Adolescent↗
PubMed2003

Nutritional status of older adults in urban Jamaica.

The aim of the study was to determine the energy intake and nutritional status of a sample of Jamaican adults, and to compare them among different age groups. Measured height and weight data from a survey in Spanish Town, Jamaica, consisting of 2100 adults aged 25-74 years, with 22 per cent over age 60 years, were used to calculate body mass index (BMI). Using BMI cut-off points of 20 and 27, the prevalence of underweight and overweight, respectively, were determined for different age groups. Energy intake was calculated from a food frequency questionnaire from 967 of the respondents. Among males, mean daily energy intake declined from a high of 3681 kcal (15,401 kJ) for 25-29 year-olds, to a low of 2227 kcal (9318 kJ) for those aged 70-74 years. Corresponding numbers among females were 2935 kcal (12,280 kJ) and 1844 kcal (7715 kJ), respectively. Among those aged 65-74 years, 26.9 per cent of males and 50 per cent of females report daily energy intakes of less than 1600 kcal (6694 kJ) (below the lowest recommended dietary allowance (RDA)), compared to 4.5 and 13.7 per cent of males and females aged 25-34 years. While there are moderate declines in the prevalence of overweight, the prevalence of male underweight increased from 4 per cent among 50-54 year-olds to over 35 per cent among those 65 years and older; and among females the corresponding numbers are from 2 per cent to 10 per cent. All trends with age were significant (p < 0.005). There are significant declines in energy intake, and alarming increases in the prevalence of underweight with increasing age among males. These results are cause for concern and further research in this area is warranted.

Adult↗
PubMed2002

The effect off-pump coronary artery bypass surgery on in-hospital mortality and morbidity.

OBJECTIVE: Off-pump coronary artery bypass (OPCAB) surgery is being increasingly reported to show better outcomes compared to conventional on bypass grafting. We examined the effect of OPCAB on in-hospital mortality and morbidity, while adjusting for patient and disease characteristics, in four institutions in the North West of England. METHODS: Between April 1997 and March 2001, 10,941 consecutive patients underwent isolated coronary artery bypass surgery at these four institutions. Of these, 7.7% were performed off-pump. We used logistic regression to examine the effect of OPCAB on in-hospital mortality and morbidity after adjusting for potentially confounding variables. RESULTS: The crude odds ratio (OR) for death (off-pump versus on-pump coronary bypass grafting) was 0.48 (95% confidence interval, CI 0.26-0.92; P=0.023). After adjustment for all major risk factors, the OR for death was 0.59 (95% CI 0.31-1.12; P=0.105). Off-pump patients had a substantially reduced risk of post-operative stroke (0.6 versus 2.3%, respectively; adjusted OR 0.26 (95% CI 0.09-0.70; P=0.008) and a significant reduction in post-operative hospital stay. Other morbidity outcomes were similar in both groups. CONCLUSIONS: Off-pump coronary artery bypass incurs no increased risk of in-hospital mortality. In contrast, there is a significant reduction in morbidity in patients undergoing off-pump coronary bypass grafting when compared to that performed on cardiopulmonary bypass.

Aged↗
PubMed2002

Delivery of glucose-6-phosphatase in a canine model for glycogen storage disease, type Ia, with adeno-associated virus (AAV) vectors.

Therapy in glycogen storage disease type Ia (GSD Ia), an inherited disorder of carbohydrate metabolism, relies on nutritional support that postpones but fails to prevent long-term complications of GSD Ia. In the canine model for GSD Ia, we evaluated the potential of intravenously delivered adeno-associated virus (AAV) vectors for gene therapy. In three affected canines, liver glycogen was reduced following hepatic expression of canine glucose-6-phosphatase (G6Pase). Two months after AAV vector administration, one affected dog had normalization of fasting glucose, cholesterol, triglycerides, and lactic acid. Concatamerized AAV vector DNA was confirmed by Southern blot analysis of liver DNA isolated from treated dogs, as head-to-tail, head-to-head, and tail-to-tail concatamers. Six weeks after vector administration, the level of vector DNA signal in each dog varied from one to five copies per cell, consistent with variation in the efficiency of transduction within the liver. AAV vector administration in the canine model for GSD Ia resulted in sustained G6Pase expression and improvement in liver histology and in biochemical parameters.

Animals↗
PubMed2002

Management preferences following radical inguinal orchidectomy for Stage I testicular seminoma in Australasia.

A survey to evaluate the preferred patterns of management of Stage I seminoma was conducted during March 2001. The questionnaire was distributed by the Royal Australian and New Zealand College of Radiologists to all qualified radiation oncologists, 74 out of 170 responded. All performed a staging CT scan of the abdomen and pelvis. Thoracic imaging consisted of either chest X-ray (29%) or chest CT (38%) while 33% performed both. Fifty-four percent of radiation oncologists discussed surveillance with their patients but estimated that 5% or less would choose this option. The most commonly prescribed dose was 25 Gy in 15 or 20 fractions (79%). Sixty-five percent of respondents treated the para-aortic (PA) nodes alone. Forty-two of 48 clinicians treating the PA field reported a change in practice after publication of the Medical Research Council study in 1999. Of these, 40 and 23% perform CT scans of the pelvis annually and every 6 months. Thirty-one percent did no follow-up CT scan. Compared to a similar survey from North America, we are more likely to use PA fields and less likely to discuss surveillance. As in the USA, and in contrast to Canada, few patients choose surveillance. There is no consensus regarding the frequency of follow-up scans in either North America or Australasia.

Follow-Up Studies↗
PubMed2002

Long-term survival after permanent pacemaker implantation: analysis of predictors for increased mortality.

AIMS: To determine long-term time-related survival and evaluate risk factors for increased mortality in patients following their first permanent pacemaker implantation. METHODS AND RESULTS: Analysis of patient records from implant to follow-up. Patient-specific time-lines were constructed to date of last review or death. Observed survival was estimated by event-free analysis using the Kaplan-Meier method. Expected survival was derived from age- and gender-matched cohorts. Risk factors for mortality were sought using the multivariate Cox proportional hazards method and risk ratios estimated. Eight hundred and thirty-three patients underwent implantation of their first permanent pacemaker from April 1992 to January 1994, and were locally followed up. Survival data were available for 803 (96.4%) patients (median age, 77.3 years [5th to 95th centile range: 53.5 to 89 5 years]) and follow-up was complete in 94.8%. At implant. dual-chamber systems were implanted in 443 (55.1%). single-chamber ventricular systems in 321 (40.0%), and single-chamber-atrial systems in 39 (4.9%). Observed survival after implantation was significantly worse than expected (P<0.001). Independent predictors of increased mortality were: age at implant (risk ratio [RR] 1.06: 95% confidence interval [CI] 1.01 to 1.12). VVI pacing mode (RR 1.64; 95% CI 1.34 to 1.93), cardiomyopathy (RR 5.86; 95% CI 4.86 to 6.86), male gender (RR 1.27; 95% CI 1.22 to 1 32) and valvular heart disease (RR 2.01: 95% CI 1.98 to 2.04). CONCLUSIONS: At the end of follow-up, mortality was much higher than expected. In this typical pacemaker population. age at implant and VVI pacing mode were independently associated with increased mortality with accompanying heart disease having the greatest individual impact.

Aged↗
PubMed2002

Outcome of Burkholderia cepacia colonisation in an adult cystic fibrosis centre.

BACKGROUND: Colonisation with Burkholderia cepacia is a poor prognostic indicator in subjects with cystic fibrosis (CF), but outcome prediction is impossible since patients are colonised by different strains with differing pathogenicity. The clinical course of a large cohort of CF patients colonised with UK epidemic (ET12) B cepacia was followed for 5 years and compared with that of the remaining patients in the clinic. METHODS: Pulmonary function, nutritional state, and lung pathogen colonisation were recorded for 5 years before December 1997 or death for all 107 patients who had attended the Liverpool adult CF clinic since 1993. For each patient a time line from study entry to date of death or 1997 was constructed. In 1993 potential risk factors including age and sex were subjected to Cox proportional hazards analysis using the end point of mortality as the outcome variable. The analysis was supplemented by time varying covariables that described the change in FEV(1), BMI, and colonisation status across time, and the excess risk associated with B cepacia colonisation was calculated. Subsequently, in those patients who died between 1993 and 1997, predictive factors for death were compared within groups using complete 5 year data. RESULTS: Thirty seven patients had been colonised by epidemic B cepacia and these patients had four times the mortality of the remainder (p<0.01). In 1993 univariate predictors of mortality were age (alive 19.6 (0.64) v dead 23.8 (1.44); p<0.005) and baseline FEV(1) (alive 68.6 (2.5)% predicted v dead 43.2 (4.8)%; p<0.001) with a trend for BMI (p=0.07). However, following time varying covariate Cox proportional hazards analysis, only lower FEV(1) (hazards ratio 1.1, 95% confidence limits 1.06 to 1.14; p<0.001) and colonisation with B cepacia (hazards ratio 7.92, confidence limits 2.65 to 23.69; p<0.001) were identified as significant factors for death. Surviving B cepacia patients had similar initial lung function to the remaining surviving patients but had an accelerated loss of lung function over the study period (colonised -1.9% predicted per year v non-colonised -0.3% predicted per year; p<0.05). Deceased patients colonised with B cepacia had better spirometric results than the remaining deceased patients 5 years before death (p<0.05) but lost lung function at a greater rate than non-colonised patients (colonised -6.2% predicted per year v non-colonised -1.9% predicted per year; p<0.05). CONCLUSIONS: This study confirms the excess mortality associated with epidemic B cepacia colonisation and shows that those with poor spirometric values are at the greatest risk.

Adolescent↗