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Biomedical subjects

A J Cook

Publications and source records attributed to A J Cook.

At least 19 recordsLinked to original sources
PubMed2005

Retreating glacier fronts on the Antarctic Peninsula over the past half-century.

The continued retreat of ice shelves on the Antarctic Peninsula has been widely attributed to recent atmospheric warming, but there is little published work describing changes in glacier margin positions. We present trends in 244 marine glacier fronts on the peninsula and associated islands over the past 61 years. Of these glaciers, 87% have retreated and a clear boundary between mean advance and retreat has migrated progressively southward. The pattern is broadly compatible with retreat driven by atmospheric warming, but the rapidity of the migration suggests that this may not be the sole driver of glacier retreat in this region.

Journal Article↗
PubMed2001

The classification of patients with chronic pain: age and sex differences.

OBJECTIVE: To further develop an empirically based classification system for chronic pain patients through the examination of age and sex differences, and incorporation of pain duration in the grouping algorithm. SUBJECTS: Three hundred seventy-four chronic pain patients (300 aged 13 to 59 years; 74 aged 60 to 89 years) assessed at an outpatient, multidisciplinary pain management centre. METHODS: Patients completed measures of demographic and descriptive information, pain intensity (box rating scale), perceived disability (modified Pain Disability Index) and affective distress (Symptom Checklist-90 Revised) before multidisciplinary treatment. Standardized scores from the assessment measures were entered into a series of hierarchical, multivariate cluster analyses to identify underlying patient subgroups. RESULTS: Age-based patient groupings from prior research were partially replicated. Significant differences in clinical presentations were observed across age and sex groups. Pain duration was found to make an important contribution to the patient groupings. 'Good control' (low pain, disability, distress) and variants of 'chronic pain syndrome' (elevated pain, disability, distress) groupings were identified across all analyses. Two variants of a 'stoic' profile were identified among older patients, with low levels of distress relative to pain and perceived disability. One of these profiles was associated with long pain duration and was found only among males. Several unique clinical profiles were identified for female patients. CONCLUSIONS: There are important age and sex differences in the clinical presentations of chronic pain patients. Some older patients present with unique clinical profiles that may reflect cohort differences, and/or physiological or psychological adjustment processes. There appears to be a greater number of distinct chronic pain presentations among females. Research on the classification of chronic pain patients within homogeneous diagnostic subgroups is needed.

Adolescent↗
PubMed2000

A meta-analysis of studies of the effect of GnRH 11-14 days after insemination on pregnancy rates in cattle.

A number of studies have used GnRH between 11 and 14 days after insemination to improve pregnancy rates in cows, however published results have not been consistent. We wished to investigate whether a consolidated estimate of the response could be quantified. Therefore we conducted a meta-analysis of the available data, 19 studies from 14 published papers, on the effect of GnRH analogs on pregnancy rate when given between Days 11 and 14 after first insemination. Odds ratios (the relative probability of pregnancy between treated and control cows) were compared for each study and found to vary significantly among studies, ranging from 0 to 22%. We showed by logistic regression analysis that response to GnRH treatment varied with cow type (beef or dairy), age (cow or heifer), estrus synchronization (synchronized or natural), pregnancy diagnosis (method and time) and effect of individual study. When all these variables were included only 6 of 14 publications could be analyzed, representing 2,541 instead of 10,945 cows. In this limited subgroup of data, a significant improvement in pregnancy rate was detected among treated cattle (odds ratio = 1.33; P<0.01).

Animals↗
PubMed2000

Sources of toxoplasma infection in pregnant women: European multicentre case-control study. European Research Network on Congenital Toxoplasmosis.

OBJECTIVE: To determine the odds ratio and population attributable fraction associated with food and environmental risk factors for acute toxoplasmosis in pregnancy. DESIGN: Case-control study. SETTING: Six large European cities. PARTICIPANTS: Pregnant women with acute infection (cases) detected by seroconversion or positive for anti-Toxoplasma gondii IgM were compared with pregnant women seronegative for toxoplasma (controls). MAIN OUTCOME MEASURES: Odds ratios for acute infection adjusted for confounding variables; the population attributable fraction for risk factors. RESULTS: Risk factors most strongly predictive of acute infection in pregnant women were eating undercooked lamb, beef, or game, contact with soil, and travel outside Europe and the United States and Canada. Contact with cats was not a risk factor. Between 30% and 63% of infections in different centres were attributed to consumption of undercooked or cured meat products and 6% to 17% to soil contact. CONCLUSIONS: Inadequately cooked or cured meat is the main risk factor for infection with toxoplasma in all centres. Preventive strategies should aim to reduce prevalence of infection in meat, improve labelling of meat according to farming and processing methods, and improve the quality and consistency of health information given to pregnant women.

Case-Control Studies↗
PubMed2000

Retrospective study of the relationships between age, inflammation and the isolation of bacteria from the lower respiratory tract of thoroughbred horses.

A total of 1235 tracheal aspirates taken from 724 thoroughbreds in race training, aged from two to 10 years, were examined cytologically and bacteriologically. An inflammation scoring system on a scale of 0 to 9 was devised to allow the severity of lower airway disease to be assessed from the cytological results. The inflammation scores were closely related to the isolation of bacteria (P<0.001), and the most common bacterial isolates were Streptococcus zooepidemicus, Streptococcus pneumoniae and Pasteurella/Actinobacillus-like species. Lower airway disease was less common in older horses (P = 0.031), and the groups at highest risk were the two- and four-year-olds. Lower airway inflammation was more common in the four-year-olds at National Hunt yards than in the four-year-olds at flat racing yards (P = 0.040, odds ratio = 3.80).

Actinobacillus↗
PubMed1999

Port-site metastasis after laparoscopic cholecystectomy for benign disease.

We describe the case history of a patient presenting with a port-site metastasis from an occult pancreatic malignancy after laparoscopy for benign gallbladder disease. While port-site recurrence is well recognized after laparoscopy for malignant disease, its presentation after laparoscopy for benign disease is rare, this being only the third such case to be reported in the literature. It emphasizes that all pathology localizing to port sites after surgery should be investigated, as it may represent the earliest sign of a hitherto occult intra-abdominal malignancy.

Adenocarcinoma↗
PubMed1998

Application of an immunoassay to determine risk factors associated with porcine cysticercosis in rural areas of Yucatan, Mexico.

A Western blot assay for identification of 26 kDa and/or 8 kDa antigens in a crude saline extract (CSE) of Taenia solium metacestodes, previously developed for human cysticercosis, was evaluated for use with pigs. The test population used for assay standardisation consisted of 45 cysticercotic pigs (5 pigs positive by necropsy and 40 selected by tongue palpation and LL-Gp immunoblot but not confirmed by necropsy), 48 pigs with heterologous infections and 40 negative controls from endemic and non-endemic areas. The test detected 93% of the cysticercotic group and was 100% specific. In a field study this antigen preparation was compared by immunoblot with antibody recognition for Gp13-50 antigens in a lentil-lectin semi-purified glycoprotein extract of T. solium (LL-Gp). The seroprevalence to CSE antigen was slightly lower (26/75) when compared to LL-Gp (29/75) and this represented a non-significant difference. The CSE Western blot assay was used to assess seroprevalence of T. solium cysticercosis in pig populations in the state of Yucatan, Mexico. A total of 1099 pigs sampled at random from 25 villages revealed a seroprevalence of 23% (253/1099). Seroprevalence in intensively reared, farmed pigs was 2% (7/228). In comparison with farmed pigs, the seroprevalence was 33% (172/513) in free-roaming backyard pigs (OR=13.86, CI=4.0747.22, p<10(-6)) and 25% (74/98) in semi-confined backyard pigs (OR=14.03, CI=5.60-35.16, p<10(-6)). There was no significant difference in seroprevalence by sex (p=0.23). Seroprevalence decreased with age (chi(2)-test for linear trend=7.803, p<0.006). Results of this study demonstrate that the CSE Western blot can be applied for reliable immunodiagnosis of T. solium cysticercosis in pigs. Furthermore, variation in pig husbandry in Yucatan indicated significantly higher exposure to cysticercosis in free-roaming backyard pigs compared to intensively reared animals from the same area.

Age Factors↗
PubMed1998

Cognitive-behavioral pain management for elderly nursing home residents.

A cognitive-behavioral pain management program for elderly nursing home residents with chronic pain was compared with an attention/support control treatment in a randomized pre-/post-comparison group design with follow-up. Thirteen women and nine men, ranging in age from 61 to 98 (M = 77.2), from two large nursing homes participated in the treatment programs through 10 weekly group sessions. Results revealed that the subjects who received the cognitive-behavioral training reported less pain and pain-related disability, although the two programs were perceived as equally credible both before and after treatment. No significant treatment effects were found for depression and physician medication ratings. Treatment effects were maintained at 4-month follow-up, despite an overall increase in reported pain. Findings indicate that elderly nursing home residents with chronic pain and without serious cognitive impairment can benefit substantially from training in cognitive and behavioral pain management strategies that are known to be effective with younger age groups and the community-resident elderly population.

Aged↗
PubMed1996

Human and bovine tuberculosis in the Monze District of Zambia--a cross-sectional study.

One hundred and seventy-six randomly selected rural households in the Monze District of Zambia were interviewed; 103 of these presented cattle for tuberculin testing. Of the 2226 cattle tested, 165 (7.4%) were positive reactors; 33% of herds contained positive animals. Risk of a positive reaction varied with an animal's age and body condition. Cattle in larger herds were more likely to give positive reactions. Ten households reported a human case of tuberculosis (TB) during the preceding 12 months; the herds or these households were six times more likely to have a tuberculin-positive animal than herds in households without a reported human TB case.

Agricultural Workers' Diseases↗
PubMed1996

Cysteinyl leukotriene involvement in chronic lung disease in premature infants.

The pathophysiology of chronic lung disease (CLD) in premature infants who require mechanical ventilation and prolonged oxygen supplementation has been well-described but the underlying mechanisms are not understood. Our aim was to test the hypothesis that excess cysteinyl leukotriene (LT) production was a contributing factor in CLD. We compared LT production and lung function, at 7 months of age, in nine premature infants with CLD and in eight control infants without CLD. None of the control infants developed any neonatal respiratory problems, but two subsequently required bronchodilator therapy. Respiratory function was assessed by the measurement of thoracic gas volume (TGV), airways resistance (Raw) and functional residual capacity (FRC). Total cysteinyl LT production was quantified by measurement of leukotriene E4 (LTE4) in a spot urine sample. Although all patients were asymptomatic at follow-up, there was evidence of significant lung function abnormalities in infants with CLD. The CLD infants had significantly elevated TGV, Raw and FRC values reflecting airway obstruction when compared to the controls. Urinary LTE4 levels were significantly higher in the CLD infants when compared to the controls (geometric mean: 741 and 337 pmol.mmol-1 creatinine, respectively). There was no direct correlation between urinary LTE4 levels in the CLD group and TGV, Raw or FRC values. Although this study is small and a direct correlation between lung function and urinary leukotriene E4 was not demonstrated, pathological lung function and an enhanced urinary leukotriene E4 production in infants with chronic lung disease would tend to suggest that the cysteinyl leukotrienes were involved in the sequelae of this disease.

Airway Obstruction↗
PubMed1994

Atopic children with cystic fibrosis have increased urinary leukotriene E4 concentrations and more severe pulmonary disease.

BACKGROUND: We investigated the hypothesis that cysteinyl leukotriene (LT) production is altered in atopic patients with cystic fibrosis (CF). METHODS: Urinary LTE4 was measured in two groups of children with CF: atopic (ACF group, n = 22) and nonatopic (NACF group, n = 13); and in two groups of unaffected children, those with atopic asthma (AA group, n = 11) and nonatopic normal control subjects (NN group, n = 12). RESULTS: Atopic groups excreted significantly more urinary LTE4 (geometric means [95% confidence intervals] in picomoles per millimole creatinine), ACF group: 104 (73-147) and AA group: 195 (136-282) compared with NACF group: 19 (9-39) and NN group: 27 (15-48). The ACF group had significantly more airflow obstruction than the NACF group, with forced expiratory volume in 1 second (percent predicted, mean +/- SD) in ACF: 58 +/- 21 versus NACF: 81 +/- 23, and forced vital capacity (percent predicted, mean +/- SD) 72 +/- 17 versus 87 +/- 23, respectively. There were significant correlations between the degree of airflow obstruction, bronchodilator responsiveness, and urinary LTE4 concentration within the entire CF group. We used multiple regression analysis to assess the respective influence of age, atopy, sensitization to Aspergillus fumigatus, and colonization with Pseudomonas aeruginosa on urinary LTE4 concentration. The atopic state was the only significant variable associated with urinary LTE4 production in subjects with CF. CONCLUSIONS: The similarities in urinary LTE4 between ACF and AA groups suggest that the atopic state is the prime determinant of urinary LTE4 excretion. Enhanced cysteinyl LT production associated with atopy in CF may increase the severity of pulmonary disease.

Adolescent↗
PubMed1994

Pain and the use of health services among the elderly.

This study examined pain management strategies and the relationship of pain to the use of health services in a sample of community-resident Canadian elderly. Analyses with the Andersen-Newman framework of need, enabling and predisposing variables revealed that pain did not make an incremental contribution to explaining service use. Traditional measures of need for services accounted for the majority of explained variance in health service use. The substantial number of participants who were found to be coping with chronic, frequent pain relied on themselves as much as formal health services for dealing with their pain. The most common coping style for these pain sufferers was a combination of analgesics and accepting mild pain as part of daily life. This combination of medical intervention and attitudinal factors appears to make the coping process very manageable.

Aged↗
PubMed1994

Characterization of the gap junction protein connexin56 in the chicken lens by immunofluorescence and immunoblotting.

PURPOSE: To characterize the chicken lens gap junction protein, connexin56 (Cx56). METHODS: The methods used were immunoblotting, immunofluorescence, alkaline phosphatase treatment, in vitro translation, and primary tissue culture. RESULTS: Connexin56 translated in vitro showed a single band with an electrophoretic mobility of approximately 66 kd. Multiple bands of 67 to 90 kd were detected in immunoblots of chicken lens homogenates using antibodies raised against a peptide from Cx56. Most, if not all, of these bands represented different phosphorylated forms of Cx56, because immunoreactive Cx56 was detected as a doublet of 65 to 67 kd after treatment of lens homogenates with alkaline phosphatase. Indirect immunofluorescence demonstrated that Cx56 was localized at membrane appositions between lens fibers and bow region cells. Levels of Cx56 increased from embryonic days 4 to 15; thereafter, levels remained fairly constant until hatching, after which they declined. Before embryonic day 9, the slowest migrating bands were not as abundant as they were at later ages. After embryonic day 20, less Cx56 was observed by immunofluorescence in the nucleus than in the cortex; however, both regions had similar levels of Cx56 as measured by immunoblotting. The pattern of bands differed between the two lens regions, suggesting differential protein modification. Immunoreactive Cx56 bands of 35 to 38 kd were detected unless homogenates were prepared in the presence of ethylenediaminetetraacetic acid (EDTA). Cx56 was also detected in lentoid-containing primary cultures derived from chicken lens. CONCLUSIONS: Cx56 is a phosphoprotein. Its appearance and modification by phosphorylation, as detected by immunoblotting, correlate with lens fiber differentiation.

Amino Acid Sequence↗
PubMed1993

Sputum tumour necrosis factor-alpha and leukotriene concentrations in cystic fibrosis.

It is postulated that a vigorous host inflammatory response in the cystic fibrosis lung contributes to lung injury. Tumour necrosis factor-alpha (TNF-alpha) may play a part in that process and in the generation of leukotrienes. Therefore, the relationships between sputum TNF-alpha, leukotriene concentration, and lung function abnormalities in 16 children with cystic fibrosis were investigated. Each subject provided sputum samples and performed spirometry. TNF-alpha was measured by enzyme linked immunosorbent assay; individual leukotrienes were separated using high performance liquid chromatography and quantified by radioimmunoassay. The geometric mean concentration of TNF-alpha was 129.7 pg/ml and 95% confidence interval 48.2 to 348.3. Mean (SEM) leukotriene B4 (LTB4) was 97.8 (22.9) pmol/g and total cysteinyl leukotrienes were 60.9 (14.8) pmol/g. Mean (SD) forced expiratory volume in one second (FEV1) of the group was 53 (15)% of predicted and forced vital capacity (FVC) was 65 (14)% of predicted. There was a significant positive correlation between TNF-alpha and both LTB4 and the total cysteinyl leukotriene sputum content. An inverse relationship existed between TNF-alpha and FEV1 and FVC. Moreover, a negative correlation was observed between sputum LTB4 and FEV1 and FVC. These results suggest that TNF-alpha and the leukotrienes may participate in the airways inflammation and airflow obstruction observed in cystic fibrosis subjects and support the hypothesis that TNF-alpha upregulates the 5-lipoxygenase pathway in vivo.

Adolescent↗
PubMed1991

Communal farmers and tick control--a field study in Zimbabwe.

Intensive dipping of cattle to control ticks and tick-borne diseases precludes development of endemic stability to the latter. Alternative control strategies have been recommended which reduce the frequency of dipping and permit the expression of tick resistance and endemic stability. However, such strategies imply acceptance by cattle owners of higher tick burdens. In this study the views of a group of communal farmers to tick control are described and the impact of these views upon adoption of other strategies is discussed.

Administration, Topical↗
PubMed1989

Death certification in fractured neck of femur.

Fracture of the neck of the femur is a major public health problem within the elderly population of most industrialised countries whose health services are increasingly being taken up with its management. Moreover, within Britain, there is evidence of a real increase in its incidence even allowing for the ageing of the population. A condition whose aetiology is still far from clear (and where no strategy for prevention can therefore be formulated), and which is of such importance to the planning and provision of services demands detailed investigation and careful monitoring. Mortality data are an important part of epidemiological studies of disease problems and, in Britain, in resource allocation through the Resource Allocation Working Party (RAWP) formula. In this study, a cohort of 2,631 elderly patients, resident in the largest health district in the country, and admitted to hospitals over a seven year period with the diagnosis of fractured neck of femur, was assembled. Hospital records were linked to national mortality data to determine whether patients had died and, where this was so, to record underlying cause of death. A total of 930 deaths occurred within the study cohort but only 52 were certified as dying from fractured neck of femur; even amongst those who died in the hospital to which they were admitted with the fracture, less than a fifth of deaths were attributed to the fracture as underlying cause. Diseases of the circulatory system accounted for almost half of all underlying causes of death and bronchopneumonia a further 20%. These findings suggest a gross undercertification of fractured neck of femur as a cause of death in the elderly and are consistent with other studies. They may be explained by a failure of junior hospital doctors to understand the importance of accurate certification of cause of death and a misguided attempt to reduce the burden to coroners of having to consider each death from this cause.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗