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Biomedical subjects

G Johnston

Publications and source records attributed to G Johnston.

At least 37 records · Page 2Linked to original sources
PubMed1998

Diagnostic imaging of osteochondrosis.

This article includes imaging of the glenohumeral (shoulder), elbow, stifle, and tarsal joints. The imaging modalities discussed are survey radiography, contrast arthrography, linear tomography, ultrasound, computed tomography, scintigraphy and magnetic resonance. Survey radiography is the first choice imaging modality for diagnosing osteochondrosis dissecans in dogs. In cases where survey radiography fail to demonstrate a lesion other modalities such as scintigraphy, linear tomography, computed tomography, and magnetic resonance may be helpful. Survey radiography, contrast arthrography, computed tomography, and magnetic resonance may also provide additional information contributing to early diagnosis and treatment.

Animals↗
PubMed1998

Parental anxiety before elective surgery in children. A British perspective.

This study measures the anxiety levels in 100 parents of children scheduled for elective surgery at the Royal Aberdeen Children's Hospital. Anxiety levels were quantified using the Leeds scale for self-assessment of anxiety. Forty-two per cent of parents were significantly anxious. Mothers were identified as being more pathologically anxious than fathers. The 'anxious' parents were specifically more anxious about the surgery, anaesthesia, postoperative pain and treatment, and hospitalisation in general. All parents, whether identified as anxious or not, agreed on factors likely to reduce anxiety: pre-operative information from staff, being able to accompany their child to the operating theatre and being present at induction of anaesthesia.

Adolescent↗
PubMed1996

Effects of prochloraz and malathion on the red-legged partridge: a semi-natural field study.

A semi-natural field study was carried out to assess the likelihood of a potentiation of toxicity between the ergosterol biosynthesis inhibiting (EBI) fungicide, prochloraz, and the organophosphorus (OP) insecticide, malathion, in the red-legged partridge (Alectoris rufa). Groups of partridges kept in four large grassland enclosures were exposed to either prochloraz-treated or control wheat for 7 days after which two of the enclosures were sprayed with malathion whilst the remaining two were sham-sprayed. Cytochrome P-450, aldrin epoxidase and 7-ethoxyresorufin-O-deethylase (EROD) activities were found to be significantly higher in the group exposed to prochloraz alone compared to controls, suggesting that induction of the hepatic microsomal monooxygenase system had occurred by ingestion of prochloraz-treated wheat. However, the level of induction produced was not sufficient to cause a potentiation of malathion toxicity. There was evidence for induction of several forms of P-450 recognised by antibodies raised against 1A1, 2C6 and 4A1 in the prochloraz-exposed partridges.

Journal Article↗
PubMed1996

Smoking among disadvantaged women: causes and cessation.

This study aimed to identify social-psychological factors associated with smoking and smoking cessation among disadvantaged women. Individual and group interviews were conducted with disadvantaged women in Atlantic Canada. Participants were predominantly poor, unemployed, geographically isolated, and single parents. The factors associated with smoking included coping with stresses, loneliness, powerlessness, low self-efficacy, social pressures, and addiction. Support from peers (i.e., women in similar circumstances) and partners was considered important. Health professionals and traditional cessation programs were not perceived as supportive. Participants viewed women's centres and women's agencies as appropriate deliverers of cessation programs. Methodological issues are discussed.

Adaptation, Psychological↗
PubMed1995

The study of interactive effects of pollutants: a biomarker approach.

Biochemical biomarkers, such as inhibition of serum butyryl cholinesterase (BuChE) and brain acetyl cholinesterase (AChE), have been useful in studies of interactive effects of pesticides in birds. Examples of interactions due to increased activation or decreased detoxication are reviewed. Studies have shown that hybrid red-legged partridges (Alectoris rufa cross) pretreated with the inducing ergosterol biosynthesis inhibiting (EBI) fungicide, prochloraz, were more sensitive to the toxic effects of the organophosphorous (OP) insecticide, malathion, than controls. A dose of 90 mg/kg prochloraz produced greater inhibition at 1, 4 and 24 h following oral administration of 50 mg/kg malathion, compared to corn oil controls. Pigeons (Columba livia) given 180 or 90 mg/kg prochloraz showed greater inhibition of BuChE activity following malathion administration than did control birds. Starlings (Stumus vulgaris), however, appeared not to be induced by 180 or 300 mg/kg prochloraz, and no difference in BuChE activity following dosing with malathion was apparent in comparison with controls. Other EBIs and OP combinations have been investigated in the partridge. Birds pretreated with prochloraz showed a trend towards greater inhibition of serum BuChE activity at most time points following dosing with the OPs dimethoate and chlorpyriphos. Birds pretreated with the EBI penconazole showed significantly greater inhibition of serum BuChE activity at 1, 4 and 24 h after malathion administration than did controls. The mechanism of increased activation of malathion due to induction of cytochrome P-450 by prochloraz is reviewed. In the case of interactions due to inhibition of detoxication, inhibition of brain AChE activity was a useful biochemical biomarker.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

A comparison between ilioinguinal-iliohypogastric nerve block performed by anaesthetist or surgeon for postoperative analgesia following groin surgery in children.

A study was performed to compare postoperative analgesia in children undergoing groin surgery. Patients were randomly allocated to receive ilioinguinal-iliohypogastric (I-I) nerve blocks using 0.25% plain bupivicaine (0.5 ml.kg-1) performed either percutaneously by the anaesthetist after the induction of general anaesthesia, before surgery commenced, or intraoperatively, under direct vision, by the surgeon. Analgesia was assessed by pain scoring in the recovery room and at hourly intervals for eight h postoperatively. Analgesic requirement was also noted. Statistical analysis of the results revealed no difference in pain score between groups treated either by anaesthetist or surgeon. However, children under two years of age had significantly higher pain scores than those over two.

Analgesia↗
PubMed1995

Women's experiences at cervical screening.

Concerns about attendance for cervical screening has focussed on determining the reasons why some women never attend. Less attention has been paid to whether women continue to attend for further smears, although this is essential for further screening. This study investigated women's experiences of cervical screening and their views on subsequent attendance. Three hundred and thirty nine women aged 20-64 were identified from a computerised register of cervical smears as having had a smear test within the previous three years. They were interviewed at home about their most recent experience of screening. Just over half of the women (53%) recalled being anxious before the test, and about one fifth reported embarrassment (19%) or pain (20%) during it. The frequencies of discomfort were higher amongst those who were anxious about the test, although 24% of those who were embarrassed and 28% who had pain reported being unconcerned beforehand. The frequencies of pain and embarrassment were only slightly higher when the smear taker was male. Many women (22%) reported being concerned about the test result although only 10% of those who were concerned were recalled for further assessment. Although a number of women had unpleasant experiences, almost all (95%) who were under 60 years of age said they were likely to attend for a subsequent smear. Taking cervical smears is often an unpleasant experience for women, although some of the distressing events could easily have been avoided. Attention to technique and to the concerns of individual patients, especially ensuring privacy, could reduce the extent of the problem. The uptake of subsequent smears should be monitored to ensure that women are not being discouraged from attendance.

Adult↗
PubMed1995

The WHO objectives for palliative care: to what extent are we achieving them?

This paper examines recent research in palliative care in the light of the guiding principles set out by the World Health Organization. It outlines the gaps in the literature and suggests priorities for future research. Areas of unmet need are documented and it is argued that research comparing outcomes across care settings and relating particular care practices to outcome measures would help to set care targets. Further definition of the expected outcomes of psychological and spiritual care, as well as care for carers, is recommended. Available measures are reviewed and suggestions made for the development of additional measures. Finally, some key methodological problems are discussed, including making cross-setting comparisons, identifying appropriate outcome measures, prioritizing patients' own identification of outcomes, using different methodologies as death approaches, and combining different perspectives offered by patients, lay carers and professional carers. The role of qualitative data as an indicator of rating scale validity is discussed in this context.

Health Priorities↗
PubMed1995

Assessing the effectiveness of a screening campaign: who is missed by 80% cervical screening coverage?

A case-control study was conducted to assess the effectiveness of a regional call programme in reaching women at risk of cervical cancer. Home interviews were conducted with a random sample of 614 women aged 20-64 who were identified from a computerized register as either having had a smear test within the previous 3 years or not having an up-to-date smear history. Unscreened women fell principally into two age cohorts: under 35 years and over 50 years. A small social class differential was found to persist following the campaign. Overall, unscreened women were not at epidemiologically higher risk than the screened population. Thirty-five per cent of unscreened women reported never having had sexual intercourse compared to 3% of screened women: 17% of the unscreened and 38% of screened women reported two or more lifetime sexual partners. No difference was observed between screened and unscreened women in the frequency of current cigarette smoking (37% unscreened, 38% screened). Cigarette smoking was, however, associated with social class (31% classes 1 or 2 compared with 50% classes 4 and 5). Level of practical difficulties did not differentiate those who attended from those who did not, suggesting that recent changes to delivery or screening services have been effective in ensuring equity of access. Non-attenders and lower class women held more negative attitudes towards the test procedure and were less likely to believe that they were at risk of cervical cancer. Perceived personal risk was not associated with cigarette smoking, suggesting that further attention might be given to this factor in educational campaigns.

Adult↗
PubMed1995

Prothrombotic events in the prodromal stages of acute laminitis in horses.

Prothrombotic changes occurring in the prodromal stages of carbohydrate-induced laminitis were investigated. Hemostatic alterations were evaluated by determining platelet counts, platelet survival, activated partial thromboplastin time, one-stage prothrombin time, and monocyte procoagulant activity. Thrombosis of vessels in the hoof wall was evaluated by contrast arteriography and histologic examination. Of 5 horses, 4 became lame between 28 and 52 hours after carbohydrate administration. Mean platelet count in laminitis-affected horses was lower throughout the prodromal stages of laminitis, compared with that in control horses, but differences were not statistically significant. However, survival of indium-111-labeled platelets was less than the value in control horses by 6 hours after carbohydrate administration. Arteriography of disarticulated feet revealed marked reduction in blood supply to hooves in laminitis-affected horses. Histologic examination of the laminar dermis disclosed microthrombi in venules of the laminar dermis in 2 of 4 affected horses. Statistically significant changes in prothrombin time were not observed, and changes in activated partial thromboplastin time were slight and occurred only at the onset of lameness. Statistically significant changes in monocyte procoagulant activity were not observed. Plasma endotoxin-like activity was not detected in laminitis-affected horses. These data indicate that platelet survival was decreased within the first 6 hours after induction of carbohydrate-induced laminitis, but systemic activation of the coagulation system was not detected.

Angiography↗
PubMed1994

Cervical screening: the optimum visit plan for contacting users and non-users in Scotland.

OBJECTIVE: To investigate the numbers of visits required to obtain interviews with users and non-users of cervical screening, and to determine the workload involved to enable an optimum visit plan to be developed. DESIGN: Case-control study of users and non-users of cervical screening using a flexible visit plan that involved up to eight attempts at contact. Visits were made in mornings, afternoons, and evenings, the visit pattern being determined by information gained from local sources. PATIENTS: Altogether 660 non-users of cervical screening (cases), aged 20-64 and registered with 23 randomly selected general practitioners (GPs), were identified from the Tayside computerised register of cervical smears. These women were selected from the computerised lists of 18 GPs in Dundee and five in Perth. A total of 417 women recorded as having a smear within the previous three years (controls), matched by age and GP, were also identified from the computerised register. RESULTS: Altogether 1834 attempts were made to contact the cases, of whom 339 were interviewed, giving a workload of 18 interviews per 100 attempts. For the controls 1359 attempts were made at contact to yield 339 interviews, a workload of 25 interviews per 100 attempts. Refusals (19%) and incorrect addresses (23%) were the two major reasons for failing to achieve interview. Only for four (0.6%) of the cases and one (0.2%) of the controls was no information gained. The proportion of attempts which led to interview remained constant with increasing numbers of call-backs (up to six for the cases and eight for the controls). CONCLUSIONS: A flexible approach to visit scheduling that takes account of local knowledge can lead to interviews with 66% of non-users of health screening, when incorrect addresses are removed. It is preferable to plan for many (up to six) visits to achieve interview. This will minimise non-response bias without increasing the workload per successful interview.

Adult↗
PubMed1994

Microvascular thrombosis associated with onset of acute laminitis in ponies.

The hypothesis that equine laminitis is caused by thrombosis of vessels in the laminar corium (dermis) was investigated. Hemostatic alterations were evaluated by determining platelet count, platelet survival, platelet adhesiveness to vascular subendothelium, activated clotting time, and whole blood recalcification time. Thrombosis of vessels in the hoof wall was evaluated by scintigraphic studies of the hoof wall after administration of indium-111 (111In)-labeled platelets, contrast arteriography, and histologic examination. Platelet count remained constant before and at the onset of lameness; however, survival of 111In-labeled platelets was shortened. Scintigraphy of affected feet revealed accumulation of 111In-labeled platelets distal to the coronary band. Arteriography of disarticulated saline-perfused feet revealed marked reduction in blood supply to affected hooves. Histologic examination of the laminar dermis disclosed variable numbers of microthrombi in dermal veins of affected feet from 3 of 4 ponies with laminitis. Whole blood recalcification time was shortened at 8 hours after administration of carbohydrate and was prolonged at the onset of laminitis. Activated clotting time was prolonged at 32 hours after carbohydrate administration and at the onset of lameness. Plasma endotoxin-like activity was detected in 1 of 4 affected ponies. These data confirm that microvascular thrombosis existed at the onset of lameness in ponies with carbohydrate-induced laminitis and indicate that systemic coagulopathy may have preceded development of thrombosis.

Acute Disease↗
PubMed1992

Changing perspective on gastrointestinal complications in patients undergoing cardiac surgery.

There has been a documented shift towards increasing age and severity of illness in the patient population undergoing cardiac surgery. To determine if there was a coincident change in frequency, gastrointestinal (GI) complications were prospectively recorded in a consecutive series of 5,438 patients undergoing cardiac surgery from 1983 to 1991. There were 73 complications in 69 patients (incidence = 1.4%) defined as any GI condition that required transfer to an acute care unit, surgical intervention, blood transfusion, or treatment that prolonged the hospital course. Fourteen patients died, a mortality rate of 20% for patients with GI complications (p less than 0.001 versus patients without GI complications). The most frequent complications were those of gastric ulceration despite routine use of H2-receptor blocking agents. Thirty-six patients had upper GI (UGI) bleeding from gastric ulceration with 4 patients requiring operative intervention to control hemorrhage and 6 fatalities in patients with UGI bleeding. Two additional patients died of septic complications following gastroduodenal perforation or penetration. Six patients experienced bowel obstruction or prolonged bowel dysfunction (three Ogilvie's syndrome) with two requiring laparotomy. There were four cases of cholecystitis, two cases of pancreatitis, and the remaining cases were equally divided among common septic complications (diverticulitis and ischemic injury among others). Three patients with massive intestinal infarction died. GI complications were significantly associated with older patients (p less than 0.01) and valve surgery (p = 0.002) but were not more common in women. When considered as a separate group, patients with acid-peptic complications had longer perfusion times, increased use of vasopressors, and more frequent utilization of the intra-aortic balloon pump. In contrast to prior studies, this investigation indicates that GI complications associated with acid-peptic erosion of the UGI tract tend to occur in a different patient group than those with other GI complications. Older patients and/or those with a prior history of peptic ulcer symptoms, as well as those who experience prolonged perfusion times, low cardiac output, or prolonged ventilatory support, should be under rigorous gastric pH surveillance and receive aggressive prophylactic treatment with high-dose H2 antagonists, antacids, and/or sucralfate.

Aged↗
PubMed1992

The minimum effective dose of lignocaine to prevent injection pain due to propofol in children.

In a single-blind study of 100 children aged 1 to 10 years, the minimum effective dose of lignocaine required to prevent injection pain due to propofol was 0.2 mg.kg-1 when veins on the dorsum of the hand were used. This is more than twice the adult value. We concluded that injection pain should not limit the use of propofol in children if an adequate amount of lignocaine is mixed immediately prior to injection.

Anesthesia, Intravenous↗
PubMed1992

Influence of cigarette smoking on the outcome of coronary care unit admissions with chest pain.

We studied the effect of current smoking habits in the period immediately before admission to hospital in 90 consecutive patients presenting with chest pain, 50 of whom were shown to have myocardial infarction. Urine cotinine/creatinine (cot/creat) ratio measured within 4 hours of admission was used as an objective marker of cigarette smoking in the preceding 18 hours. Fifty-seven patients had urine cot/creat ratios suggesting recent smoking, although four of these denied smoking. Patients with myocardial infarction had higher median cot/creat ratios (3.31 micrograms/mg, range 0-17.8) compared with patients with non-infarct chest pain (0.5 microgram/mg, range 0-37.2). Sixteen patients with cardiac rhythm disturbances following infarction had significantly higher cot/creat ratios than the 34 infarct patients without this complication (median and range 8.34 micrograms/mg; 0-17.8 V. 1.87 micrograms/mg; 0-16.4, P < 0.01). Tobacco use in the 24 hours before myocardial infarction may predispose to cardiac rhythm disturbance, irrespective of infarct size.

Adult↗
PubMed1992

An evaluation of prototype school-based peer counseling program.

This study reports short-term outcome evaluation results of a school-based peer counseling (PRC) program as implemented by North Forsyth High School during January 1990-February 1991. The PRC program is evaluated in terms of: 1) the content of the program as evaluated by the PRC trainees; 2) the quality of the PRC instructor as perceived by these trainees; 3) several instrumental objectives deduced from the PRC training program; and 4) the degree to which the program was able to reach other students at North Forsyth during the time the PRC was in operation. In the absence of a control group, the treatment effect of the program is determined in terms of individual growth curve models. Through the multiple evaluation designs employed in this research, it has been learned that a significantly larger proportion of students in the PRC group had more favorable attitude toward the content of the PRC program when compared to the content of what they learned from their regular school curricula. Furthermore, a significantly larger proportion of students in the PRC program reported more favorable attitude toward their instructor than their regular school teachers. The PRC program was able to elicit an improvement of trainee self-esteem (p less than .01) and their social values (p less than .05) between pre and post of the Peer Training Evaluation Instrument. In terms of client access, 18.4 percent of the totality of potential clients at North Forsyth have been reached through sixty-one peer counselors sanctioned by the school.

Adolescent↗