Biomedical subjects

M J Power

Publications and source records attributed to M J Power.

At least 37 records · Page 2Linked to original sources

PubMed1994

The impact of social cognitive variables on the initial level of depression and recovery.

Thirty-seven patients who fulfilled DSM-III-R criteria for Major Depressive Disorder were recruited for a double-blind controlled trial of Desipramine and placebo for 6 weeks. Data about social cognitive variables, including social adversities, investment in roles and goals, general social support and crisis support were collected. Crisis support had a moderating effect on the initial level of depression: the more crisis support the subjects had, the less depressed they were on recruitment. Initial level of depression, the experience of adversity and drugs all contributed significantly to recovery defined as Hamilton Rating for Depression less than 10 at week 6. When recovery was defined as Hamilton score halved or more than halved between week 2 and week 6, subjects' level of ideal emotional support, and whether they had experienced adversity in their most invested domains, contributed significantly to recovery, independent of any drug effects or the initial level of depression. The higher their level of ideal emotional support, the less was the chance of these subjects recovering. The findings of this study pointed to the importance of controlling for psycho-social variables in studies of response to treatment.

Adult↗

PubMed1994

Radioimmunoassay of 2-hydroxyestrone in urine.

Catechol estrogens such as 2-OH estrone are interesting estrogen metabolites formed in several human tissues and excreted in urine. We developed and thoroughly validated a radioimmunoassay for urinary 2-OH estrone that has several advantages over published RIAs. Because we developed a relatively specific antiserum, we did not include a preliminary chromatographic step to eliminate cross-reacting urinary steroids. We hydrolyzed urinary steroid conjugates with beta-glucuronidase from Helix pomatia because recoveries after acid hydrolysis were only 49.6% compared with 73.8% after enzyme hydrolysis. Published RIAs for urinary 2-OH estrone use acid hydrolysis. Our RIA measured 2-OH estrone independently of the volume of sample, and the detection limit was between 100 and 240 ng/L (10-24 pg per tube). The ED50 was 370 ng/L, and inter- and intraassay CVs for low, medium, and high concentrations were 22.5%, 22.8%, and 19.9%, and 17.4%, 14.3%, and 10.8%, respectively. Median concentrations measured in 14 controls and 33 postmenopausal patients with breast cancer were 0.96 and 1.55 micrograms/g creatinine, respectively, but there was considerable overlap between values from controls and patients.

Adult↗

PubMed1993

Tactics for the control of wildlife rabies in Ontario (Canada).

Two different tactics are currently being utilized to control rabies in foxes, skunks and raccoons in Ontario, Canada. The first tactic, which involves live-capturing with cage-traps and vaccinating by intramuscular injection, was successful in immunizing 54%-72% of the skunk and raccoon populations in a 60 km2 area of Toronto, Ontario. This area has been free of rabies for two-and-a-half years. The second tactic, involving the distribution of baits containing modified live-virus (ERA) rabies vaccine, was implemented to control rabies in foxes in both urban and rural areas of Ontario. In Toronto, 50% and 63% of the foxes were vaccinated during 1989 and 1990, respectively. Over the same period, 45% and 61% of the foxes in a 30,000 km2 area of south-eastern Ontario were immunized. Rabies is declining in both of these areas. A contingency plan has been devised to control an epizootic of raccoon rabies which is threatening to invade Ontario from the United States of America.

Administration, Oral↗

PubMed1993

Sandwich enzyme immunoassay of osteocalcin in serum with use of an antibody against human osteocalcin.

We have developed and thoroughly validated a solid-phase sandwich enzyme-linked immunosorbent assay (ELISA) on microtiter plates for osteocalcin in human serum with use of an antibody raised against human osteocalcin. We used a monoclonal antibody against bovine osteocalcin as the capture antibody; the second antibody was a polyclonal antibody against human osteocalcin. The amount of bound second antibody was determined with use of swine anti-rabbit antibody labeled with horseradish peroxidase. We demonstrated independence of volume and determined the recovery of added standard and within- and between-assay precision. The minimal detection limit for osteocalcin was between 1.0 and 1.5 micrograms/L and the midpoint of the standard curve ranged from 14 to 17 micrograms/L. The intraassay CV was < or = 8% in the range 2.7-52 micrograms/L; the interassay CV was usually < or = 15% in the same range. Analytical recovery of human osteocalcin standard added to serum samples was consistently > 90%. Values for osteocalcin measured in serum from 44 normal subjects were similar to those obtained with a competitive enzyme immunoassay (EIA) that used a monoclonal antibody against bovine osteocalcin. There was a good correlation between the two assays [r2 = 0.877, slope and intercept (+/- SE) = 0.88(+/- 0.051) and 0.316(+/- 0.523), respectively]. The range and mean (+/- SD) for the sandwich ELISA and the competitive EIA were 1.7-18.1 micrograms/L [8.7(+/- 4.4) micrograms/L] and 1.9-22.8 micrograms/L [9.1(+/- 4.4) micrograms/L], respectively.

Animals↗

PubMed1993

Pancreatic polypeptide and exocrine pancreatic function in the elderly.

The relationship between exocrine pancreatic function and plasma pancreatic polypeptide levels was studied in 14 normal elderly subjects and in ten elderly patients with exocrine pancreatic insufficiency determined by the para-amino-benzoic acid test. There was a decrease in the total pancreatic polypeptide response after a standard mixed meal in the group with pancreatic insufficiency (t = 2.753, p = 0.01). An increase above basal of less than 100% in plasma pancreatic polypeptide levels 30 min after a standard mixed meal is strongly associated with exocrine pancreatic insufficiency (Fisher's exact test, p = 0.005).

4-Aminobenzoic Acid↗

PubMed1992

Social networks and support in long-term psychiatric patients.

This paper describes quantitative and qualitative aspects of social support in a sample of 40 long-term schizophrenic day patients attending a rehabilitation unit. The influence of symptomatology and experience of life stressors on network and support characteristics was also investigated. The primary networks of these patients were found to be small, comprising on average 7 members, of whom only 3 were seen regularly. Despite this, subjects rated their perceived support as adequate. The secondary networks were of the order of 32. It emerged that greater prevalence of negative symptoms was significantly associated with lower ideal levels of support and this group of patients was significantly less likely to seek support in the event of a life stressor. This may be a protective mechanism to insulate the person from the effects of stressful relationships but at the same time means that they are isolated from potential supports. The clinical implications are discussed in terms of offering optimum support for this marginalized group.

Adolescent↗

PubMed1992

Exocrine pancreatic insufficiency in presumed healthy elderly subjects.

A pilot study on exocrine pancreatic function, using the 2-day para-aminobenzoic acid (PABA) test, was performed on 21 healthy elderly and 26 healthy young subjects. A PABA excretion index (PEI) less than 55%, indicating moderate to severe exocrine pancreatic insufficiency (EPI), was found in 19% of the elderly group (95% confidence limits 5-42%). While the mean value of the PEI was significantly lower in the elderly compared with the young group (Mann-Whitney Z = 2.8, p less than 0.01), there was no significant difference when the elderly subgroup with PEI less than 55% was excluded. There was no evidence of a generalized moderate to severe decline in pancreatic exocrine function with increasing age; a mild to moderate decline cannot be excluded.

4-Aminobenzoic Acid↗

PubMed1992

Causal beliefs about depression in depressed patients, clinical psychologists and lay persons.

Non-depressed lay persons have been shown to have extensive and accurate knowledge about depression (Rippere, 1977, 1980 a, b, 1981 a) that is underpinned by a structure that resembles current academic theories of the disorder (Furnham & Kuyken, 1991). In this study a semi-structured interview schedule and a number of rating scales were used to determine and compare the nature and extent of depressed patients', clinical psychologists', and lay persons' beliefs about the causes of depression. We confirmed that depressed patients and non-depressed lay persons alike have relatively extensive beliefs about the causes of depression which are comparable to those held by clinical psychologists. However, depressed patients tend to endorse biological explanations of the causes of depression to a greater extent than clinical psychologists. In contrast, clinical psychologists assign a more important causal role to unconscious processes and childhood vulnerability factors than do either depressed patients or non-depressed lay controls.

Adjustment Disorders↗

PubMed1992

Trap-vaccinate-release and oral vaccination for rabies control in urban skunks, raccoons and foxes.

Two rabies control tactics, trap-vaccinate-release (T-V-R) and oral vaccination were used for the control of rabies in skunks (Mephitis mephitis), raccoons (Procyon lotor), and foxes (Vulpes vulpes) in metropolitan Toronto, Canada. Using T-V-R, a mean of 45% to 72% (95% confidence limits of 40% to 81%) of the skunks and a mean of 17% to 68% (95% confidence limits of 14% to 76%) of the raccoons in a 60 km2 area of Toronto were vaccinated against rabies between 1987 and 1991. The area has been free of skunk rabies from May 1989 to April 1992. Forty-five rabies cases were diagnosed during 1980 to 1986. In contrast, only three skunk cases have been reported since the vaccination program began in July 1987. The T-V-R area also remained rabies free during an epizootic of skunk rabies in metropolitan Toronto during 1991. Following distribution of rabies vaccine-baits throughout the ravines of metropolitan Toronto, June 1989 to December 1991, 46% to 80% of the Toronto fox population was immunized during 1989, 1990 and 1991. Only one case of fox rabies was reported in metropolitan Toronto since vaccination began, compared to 80 cases reported between 1982 and 1988. The area has been free of reported fox rabies from October 1990 to April 1992.

Administration, Oral↗

PubMed1991

A questionnaire designed to assess roles and goals: a preliminary study.

Social-cognitive theories of depression predict that an individual is at more risk of becoming depressed if the individual's only dominant role or goal is disrupted by a life-event. This paper reports the development of an instrument which assesses the individual's important roles and goals; preliminary data are presented from two samples (sample 1 of elderly people, sample 2 of younger adults) taken from the age-sex registers of GP practices. The overall reliability of the questionnaire is good, and evidence was obtained for the predicted pattern of an overvalued role or goal being more likely to be correlated with depressive symptomatology.

Activities of Daily Living↗

PubMed1991

Osteocalcin: diagnostic methods and clinical applications.

Osteocalcin is a small (Mr 5800), very interesting bone specific protein, synthesized by osteoblasts and measured in plasma as a biochemical indicator of bone formation. Many immunoassays for osteocalcin have been developed, including radio- and enzymoimmunoassays, with the use of monoclonal and polyclonal antibodies. These are used in many different clinical settings, including bone, kidney, and liver diseases. However, there is a wide range of published values for plasma osteocalcin concentrations in control and patient samples and this has hindered a more widespread adoption of osteocalcin measurement by clinicians. This review discusses how various immunoassays for osteocalcin may contribute to the wide variation of published values and suggests approaches for the development of standardized assays. For example, epitope specificity and immunoreactivity with multiple forms of osteocalcin and osteocalcin peptides in plasma are discussed. It also includes a recent update on interesting clinical applications of osteocalcin.

Aging↗

PubMed1991

Osteocalcin concentrations in plasma prepared with different anticoagulants.

We investigated the effects on plasma osteocalcin concentrations of different anticoagulants used to collect the blood samples. Plasma osteocalcin concentrations measured by enzyme immunoassay and radioimmunoassay are influenced by the nature of the anticoagulants used. The most significant difference between concentrations found in plasma and serum was seen with oxalate/fluoride anticoagulant, which reduced osteocalcin concentrations to 37.3% of serum values. This is probably related to increased hemolysis with this anticoagulant compared with osteocalcin concentrations in plasma prepared with other anticoagulants. Samples prepared with sodium citrate (0.105 mol/L) or lithium heparin gave values 92.4% and 83.6% of those obtained with matched serum samples. Osteocalcin concentrations were relatively stable in plasma and serum at -20 degrees C for two freeze/thaw cycles. In blood from 100 patients there was a good correlation between osteocalcin concentrations in serum and plasma (lithium heparin) (r2 = 0.831); the slope and intercept (+/- SE) were 0.924 +/- 0.04 and 4.92 +/- 1.25 micrograms/L, respectively. However, in 10 patients, serum osteocalcin concentrations were two- to threefold higher than those in matched plasma samples.

Adult↗

PubMed1989

Solid-phase enzymoimmunoassay for osteocalcin in human serum or plasma, with use of a monoclonal antibody.

In this solid-phase enzymoimmunoassay on microtiter plates for osteocalcin in serum or plasma, we use an osteocalcin-horseradish-peroxidase conjugate and a monoclonal antibody raised against bovine osteocalcin. We thoroughly standardized the assay for measurement of osteocalcin in both serum and plasma, demonstrating independence of sample volume, and determining the analytical recovery and within-and between-assay CVs. The detection limit was between 0.6 and 1.1 micrograms/L and the ED50 was 16 micrograms/L for a 5-microL sample volume. The intra-assay CV over the range 3 to 74 micrograms/L was less than or equal to 15%. The interassay CV over the range 3.6 to 46 micrograms/L was less than or equal to 16%. Results by this assay and by an in-house radioimmunoassay in which the same monoclonal antibody was used correlated well (r2 = 0.948). Osteocalcin concentrations in serum and plasma as measured with the present assay agreed well with published values.

Adult↗

PubMed1989

Radioimmunoassay of osteocalcin with polyclonal and monoclonal antibodies.

We have developed and thoroughly validated radioimmunoassays (RIAs) for osteocalcin in plasma and serum, demonstrating independence of volume and determining the recovery of added standard and within- and between-assay precision. Antibodies were raised in rabbits and mice by immunization with either osteocalcin adsorbed to polyvinylpyrrolidone or osteocalcin conjugated to bovine serum albumin. In both species, use of the conjugated osteocalcin was more efficacious. Correlation of the results obtained when groups of plasma or serum samples were analyzed by RIAs with different antibodies (two polyclonal and one monoclonal) indicated that the normal range observed for osteocalcin concentrations in serum depends on the antibody used. These findings may account for the wide range of "normal" osteocalcin values reported by different groups.

Adult↗

PubMed1988

The "worst ever" version of the General Health Questionnaire.

This study reports the development of a "worst ever episode" version of the Goldberg and Hillier (1979) GHQ-28. The scale was designed to provide a short self-report instrument for use with the general population that could be used to identify past episodes of psychopathology likely to be of clinical significance. Preliminary results together with values for 6-month test-retest reliability are reported for a sample of mature students.

Adult↗

PubMed1988

Blood glucose and prognosis of acute stroke.

To study the relation of blood glucose soon after the onset of stroke and outcome in terms of fatality and functional recovery 6 months later, two prospective studies were performed. Fasting blood glucose measured within 48 hours of onset was significantly higher in those who died than in those who survived. However, random blood glucose, mean daily blood glucose and HbA1 were not related to fatality or functional recovery. Fasting blood glucose levels soon after the stroke were significantly higher than those in the same patients measured 1 month later. These results suggest that the hyperglycaemia related to decreased survival is a stress response rather than an indication of preexisting diabetes mellitus but do not support the view that a high blood glucose level is itself harmful to the brain.

Cerebrovascular Disorders↗

PubMed1988

The development of a measure of social support: the Significant Others (SOS) Scale.

A description is presented of the development of a new scale to measure social support which is called the Significant Others (SOS) Scale. The scale measures different functional resources of social support that may be provided by a number of significant role relationships within an individual's social network. Preliminary results from a sample of mature students show that the scale has good six-month test-retest reliability, and significantly distinguishes between depressed and non-depressed respondents. Details of a short form of the scale currently being developed are also presented.

Adult↗

PubMed1988

Multidisciplinary assessment of applicants for residential accommodation.

Fifty of 62 applicants for residential accommodation underwent assessment at a geriatric day hospital. Twenty-five were suitable, 11 were suitable following rehabilitation and 14 were unsuitable for placement in residential accommodation. Around 35% of all applicants were not assessed. Seventy-nine per cent of assessed applicants, without dementia, either were unsure of how their application had been initiated or did not understand the implications of a move to residential accommodation. Twenty-two per cent of all applicants assessed were taking four or more drugs. To maximise the use of residential accommodation, all applicants should be assessed to reduce inappropriate referrals.

Aged↗