Biomedical subjects

J Mitchell

Publications and source records attributed to J Mitchell.

At least 91 records · Page 5Linked to original sources

PubMed2000

Quality attributes and storage stability of locally and mechanically extracted crude palm oils in selected communities in Rivers and Bayelsa states, Nigeria.

The effect of different extraction methods on the quality of crude palm oil processed using traditional (local) and mechanical methods in selected areas of Rivers and Bayelsa States and their storage stability were investigated. Certain quality determining parameters such as free fatty acids (FFA), peroxide value (PV), saponification value (SV), moisture, impurities and volatile matter (MIV) content were determined prior to and after storage for three months. The free fatty acids (FFA) ranged from 7 to 19 percent, peroxide value (PV) ranged from 3 mEq/kg to 6 mEq/kg and moisture, impurity and volatile matter (MIV) ranged from 0.21 to 0.64 percent for locally extracted crude palm oil samples and mechanically extracted crude palm oil samples. There was no significant difference (p > 0.05) in the FFA of samples A and E before and after storage for 3 months. Also two of the locally extracted crude samples (A and E) stored better while one of the samples (D) showed a high level of deterioration as shown in its high levels of FFA, PV and IV values. Samples A and E resulted in a better quality of oil in terms of FFA (av. 7.25%) and PV (av. 4.5 meg/kg) when compared to the mechanically extracted one (sample C) with FFA (10.0%) and PV (5.78 mEq/kg). However, all the locally and mechanically extracted crude palm oil samples could not meet the industrial and international standard quality for crude palm with FFA (2-5%) and PV (2-3.5 mEq/kg). Among the three different storage containers used under different storage conditions, plastic containers (PC) resulted in a better storage stability of the crude palm oils in terms of FFA, SV, and IV than transparent bottles stored on shelves (TBS) and amber-colored bottles stored on the bare floor (BPF).

Fatty Acids, Nonesterified↗

PubMed2000

Q-sort assessment of attachment security during the preschool years: links from home to school.

This study investigated relations among preschoolers' secure-base behavior with mother at home, stressful family conditions, and qualities of developing relationships with peers and teachers in preschool. Preschool-age children (N = 94; 51 boys and 43 girls) and their mothers were observed during multiple home visits, and their security of attachment was assessed with the Attachment Q-Set. Children in families with lower levels of stress had more secure attachment relationships with mothers. Both boys and girls who were less securely attached to their mothers expressed significantly more anger-aggression in preschool. For boys, higher levels of family stress were also significantly related to anger-aggression and to social competence in preschool. In addition, boys who were more securely attached to their mothers were more securely attached to their preschool teachers and were more popular with peers in preschool.

Child, Preschool↗

PubMed2000

Identification of genetic heterogeneity in Refsum's disease.

Refsum's disease (MIM 266500) is a recessive disorder characterised by defective peroxisomal alpha-oxidation of phytanic acid. A Refsum's disease gene, phytanoyl-CoA hydroxylase (PAHX), has been localised to chromosome 10p13 between the markers D10S226-D10S223. This study investigated whether all cases of Refsum's disease were linked with chromosome 10p13. Eight genetically informative families comprising 92 individuals including 17 living patients with a Refsum's disease phenotype and initial plasma phytanic acid > 200 micromol/L were recruited. Linkage to the 10pter-10p11.2 region was investigated using a panel of eight dinucleotide repeat markers. Linkage analysis of this phenotypically identical cohort suggested that Refsum's disease was genetically heterogeneous (Zmax = 5.28, alpha = 0.45). Two subgroups were identified. One group of four families with eight affected individuals had a maximum multipoint lod score for linkage of 3.89 in the region D10S547 to D10S191, whilst in another three families with nine affected individuals linkage to this region was definitely excluded. Our results show that Refsum's disease is genetically heterogeneous, with up to 55% of cases not being linked to the PAHX gene locus at D10S547 to D10S223. This suggests that Refsum's disease, in common with other peroxisomal 'diseases', may be more accurately described as a heterogeneous syndrome.

Chromosome Mapping↗

PubMed2000

Identification of small FRAXA premutations.

BACKGROUND: Diagnosis of fragile X syndrome in mentally retarded individuals is satisfactorily achieved using a Southern blot test that detects the typical triplet repeat expansion (>200 repeats) within the FMR1 gene. All such individuals inherit the mutation from a carrier, who usually shows a lower triplet repeat number and may be asymptomatic. Having identified a fragile X proband, it is necessary to identify related carriers of this familial X-linked dominant mutation to provide family counseling and testing. METHODS AND RESULTS: For one family in which a fragile XA repeat expansion occurs, Southern blot hybridization did not give accurate sizing data because of the very small premutation associated with the unstable allele. PCR sizing methods and linkage analysis were adapted to identify family members with the premutation. CONCLUSION: Although most carriers can be detected using Southern blot and/or direct PCR sizing tests, very small expansions (55-70 repeats) are difficult to distinguish from larger, normal alleles. We have used linkage analysis in combination with direct allele analysis to identify carriers of very small expansions of a fragile X chromosome in a four-generation family.

Blotting, Southern↗

PubMed2000

Teleradiology at the tertiary-level Women's and Children's Hospital in South Australia.

This article relates to a teleradiology trial undertaken in 1998-1999 at the Women's and Children's Hospital (WCH) in Adelaide, the capital of South Australia. The trial involved linking the hospital to a range of rural and remote sites in South Australia and the Northern Territory. The main aim of the project was to evaluate the advantages, limitations, benefits, and costs of a teleradiology service provided by WCH. The major finding from the study is that for a tertiary hospital providing second opinions in complex medical cases, a new form of business justification is required for teleradiology. The justification would include an emphasis on the range of high-level services that a subspecialist hospital such as the WCH can provide. The justification would also include the range of benefits to different parties, particularly the patient, and the intangible nature of many of the benefits.

Adult↗

PubMed2000

Quantifying the association between habitual energy expenditure and blood pressure.

BACKGROUND: Previous studies have demonstrated an association between physical inactivity and hypertension, but the methods used to assess activity have been subjective and imprecise. Recently methods have become available allowing measurement of energy expenditure in free-living populations. Our aim was to employ these methods to assess the independent association between energy expenditure, cardio-respiratory fitness and blood pressure. METHODS: In a cross-sectional study of 775 people (45-70 years) participating in a continuing population-based cohort study, energy expenditure was assessed by 4 days of heart rate monitoring with individual calibration of the relationship between heart rate and energy expenditure, a method validated against doubly-labelled water and whole body calorimetry. Cardio-respiratory fitness was assessed in a sub-maximal test. To adjust for measurement error in the assessment of usual energy expenditure and fitness, 190 subjects repeated both tests on three further occasions at 4-monthly intervals. RESULTS: A highly significant linear trend in blood pressure was found across quintiles of the physical activity level, the ratio of total energy expenditure to basal metabolic rate. The differences in the mean systolic/diastolic blood pressure between the top and bottom quintile was 6.3/4.4 mmHg in men and 10.7/5.9 mmHg in women. These effects were independent of obesity and cardio-respiratory fitness. Correction for measurement error suggests that the true underlying relationship between usual energy expenditure and blood pressure is stronger still. CONCLUSIONS: These findings are compatible with a strong association between usual energy expenditure and blood pressure and support public health strategies aimed at increasing overall energy expenditure.

Aged↗

PubMed2000

A randomised trial of an intervention to develop health promoting schools in Australia: the south western Sydney study.

OBJECTIVE: This paper describes the evaluation of a health promoting schools intervention carried out in the south western region of Sydney, Australia. The evaluation sought to assess the project's impact on structures to support the health promoting school concept and changes in health-related policies and practices within 22 local schools. METHODS: A randomised controlled study was employed. Intervention schools were offered seminars and training in the health promoting schools concept, encouraged to use a resource kit to help them establish their school as health promoting and invited to participate in a support network. Pre- and post measures of awareness, school structures and policies and practices to support the development of a health promoting school were taken and intervention and control schools compared. RESULTS: There was an increased level of awareness of the health promoting school concept among intervention schools. However, there were no significant changes in health-related policies and practices at the school level, among both intervention and control schools. CONCLUSIONS: A longer time frame and more structured support are required to influence school structures to support the development of a health promoting school. IMPLICATIONS: To facilitate organisational change in schools, health promoting school interventions need to provide structured support for schools and recognise that change takes time. A committee to initiate action, a plan to guide work and school support are likely to facilitate the adoption of the health promoting schools approach. Further work to refine the measurement of school-based action and its outcome and the development of indicators for a health promoting school is needed.

Health Policy↗

PubMed2000

Physiotherapy for anterior knee pain: a randomised controlled trial.

OBJECTIVE: To determine the efficacy of the individual components of physiotherapy in subjects with anterior knee pain. METHODS: An observer blind, prospective, factorial design randomised controlled trial. 81 young adults with anterior knee pain were randomly allocated to one of four treatment groups: (1) exercise, taping, and education; (2) exercise and education; (3) taping and education; and (4) education alone. Each group received six physiotherapist-led treatments over three months. Follow up took place at three months using the following outcome measures: patient satisfaction (discharge/refer for further treatment); a visual analogue pain score; the WOMAC lower limb function score; the Hospital Anxiety and Depression scale (HAD); and quadriceps strength. At 12 months the WOMAC and HAD were assessed by postal questionnaire. RESULTS: All groups showed significant improvements in WOMAC, visual analogue, and HAD scores; these improvements did not vary significantly between the four groups or between exercising/non-exercising and taped/non-taped patients at three and 12 months. However, patients who exercised were significantly more likely to be discharged at three months than non-exercising patients (chi(2), p<0.001). Taping was not significantly associated with discharge. Significantly greater improvements in WOMAC, visual analogue, and the anxiety score (but not the depression score) were seen in patients who were discharged than in those who were referred. CONCLUSIONS: The proprioceptive muscle stretching and strengthening aspects of physiotherapy have a beneficial effect at three months sufficient to permit discharge from physiotherapy. These benefits are maintained at one year. Taping does not influence the outcome.

Adolescent↗

PubMed2000

Increasing the cost-effectiveness of telemedicine by embracing e-health.

In 1999 a national study of telemedicine in Australia led to the promotion of the concept of 'e-health', the health sector's equivalent of 'e-commerce'. A new study explored the view that, with the convergence of technologies and the consequent increase in ability to perform multiple functions with those technologies, it is unwise to promote telemedicine in isolation from other uses of technologies in health-care. The major sources of information for the study were the presentations and discussions at five national workshops held to discuss the findings of the original report on telemedicine. Nineteen case studies were identified. The case studies showed that with the convergence of technologies telehealth is becoming part of e-health. The cost-effectiveness of both telehealth and telemedicine improves considerably when they are part of an integrated use of telecommunications and information technology in the health sector.

Australia↗

PubMed2000

The cost-effectiveness of teleradiology at the Women's and Children's Hospital in Adelaide.

The cost-effectiveness of teleradiology was examined in a trial conducted at the Women's and Children's Hospital (WCH) in Adelaide, from February 1998 to February 1999. The trial showed that, with the large distances between remote hospitals and metropolitan hospitals, teleradiology, relative to the transfer of remote patients, could be highly cost-effective, but that a new form of cost justification is required for teleradiology for tertiary hospitals providing second opinions in special cases. A series of compelling case studies proved the economic and social value of teleradiology at the WCH.

Child↗

PubMed2000

An evaluation of a network for professional development in child and adolescent mental health in rural and remote communities.

In 1998 a telemedicine network was established in South Australia and the Northern Territory to deliver educational material to professionals working in child and adolescent mental health in remote areas. The network involved a wide range of health professions, from psychiatrists to psychologists and social workers. The first 12 months of network activity were evaluated by quantitative and qualitative techniques. Four sources of data were used: an activity log, questionnaires, interviews and action research. A total of 36 telemedicine sessions were held, ranging in duration from 45 to 90 min (average 56 min) and involving a total of 45 different professionals, who participated an average of four times each (range 1-15). The most common types of session were case discussions (47%), followed by specialist seminars (36%) and administrative and introductory sessions (17%). The benefits of the network included: networking and peer support; improved efficiency and reduced travel costs; and improved efficiency of health services. The problems included: costs; lack of access to technical support; and the need for staff induction and training.

Adolescent↗

PubMed2000

An evaluation of satisfaction with telemedicine among health-care professionals.

A survey was conducted among non-doctor health-care professionals in six rural counties in Missouri. The purpose of the survey was to establish baseline data to evaluate the effect of changes in the health-care sector, especially technology changes, on the job satisfaction, career satisfaction, relationships and communication activities of health professionals. The survey included three rural counties in which integrated telecommunication and interactive video telemedicine services were being installed, but before significant activities had begun, and three comparator counties without substantial integrated telecommunications infrastructure and telemedicine services. During a one-month study period, 1108 questionnaires were distributed. The total response rate was 50.1% (n = 555). Of the respondents, 30.3% indicated that technology in health-care was having a large effect on their work, although only 18.2% indicated that telemedicine and telecommunications were having a large effect. No systematic differences were found among the health professionals in the two communities at the time telemedicine equipment was being installed.

Health Knowledge, Attitudes, Practice↗

PubMed2000

Calcium hydroxylapatite deposition disease in a Great Dane Puppy.

A 10-week-old male Great Dane Puppy was presented for sudden onset tetraataxia and severe paresis of the front legs. Mineral deposits were detected radiographically, at gross postmortem examination, and light microscopically between the vertebral arches of multiple cervical and lumbar vertebrae. These deposits were associated with the interarchial ligaments (ligamentia interarcualia), along the interfaces of the synovium and articular cartilage of multiple cervical, thoracic, and lumbar facets, on the dorsal aspect of several thoracic intervertebral discs, and at the insertion of muscles at the lateral aspect of several cervical and thoracic vertebral bodies. The mineral deposits were associated with a granulomatous inflammation and synovial fibrocartilaginous metaplasia and proliferation, which was focally exuberant. X-ray diffraction analyses of the mineral deposits revealed calcium hydroxylapatite as the major component. The clinical signs in this puppy were due to focal compression of the spinal cord by marked extraarticular ligament-associated fibrocartilaginous proliferation.

Animals↗

PubMed1999

Clinical characteristics of SOD1 gene mutations in UK families with ALS.

Five to ten percent of patients with ALS have a family history of the disease, inheritance is usually autosomal dominant. Mutations of the SOD1 gene were first identified in a proportion of families with ALS by Rosen et al. The SOD1 gene encodes the enzyme copper zinc superoxide dismutase. Patients were studied from throughout the UK, where more than one individual in the family had ALS. Clinical history and examination of the individual and family were obtained, and DNA extracted from leukocytes of whole blood samples. Mutations were identified by standard sequencing methods. To date, 12 different mutations of SOD1 have been identified in 17 different families, representing around 20% of all ALS families studied. The mutations were mainly single base substitutions - H48Q, G72S, G93R, G93V, E100G, D101N, D101G, G108V, I113T, D125H, I149T - and also an insertion mutation - 132insTT - leading to a premature stop codon. The mutations were present in exons 2-5. We did not identify mutations in exon 1, although these have been identified by others in different patient samples. We have identified SOD1 mutations in around 20% of UK families with ALS studied. This is similar to that reported in other populations. Mutations have now been identified in all exons of SOD1. The individual mutations do not precisely predict disease severity, and generally it is difficult to give a specific prognosis based on the individuals' SOD1 mutations. We continue to investigate the possible pathogenic mechanisms of the SOD1 mutations. We have studied the neuropathology in patients with SOD1 mutations. We are also performing linkage studies to identify the genes involved in the 80% of families where an SOD1 mutation has not been identified.

Adult↗

PubMed1999

Human lens cholesterol concentrations in patients who used lovastatin or simvastatin.

OBJECTIVE: To determine whether long-term therapeutic use of the hypocholesterolemic drugs lovastatin and simvastatin significantly alters the distribution and concentration of cholesterol in the human lens. Such changes might precede observable alterations in lens structure. METHODS: Pairs of lenses (9-13 pairs) from patients (age range, 46-81 years) who had been taking lovastatin or simvastatin before their death (estimated for the previous 2-4 years) and lenses from similarly aged control subjects were divided into outer cortex and inner cortex plus nucleus by dissolution in a detergent-containing buffer. Ten minutes of dissolution removed 17% to 19% of the lens total volume, which accounted for about 20% of the width of the equatorial cortex and 75% of the width of the sagittal cortex. This fraction plus the residual lens was homogenized, saponified, and assayed for cholesterol by gas-liquid chromatography. RESULTS: The cortex of adult control lenses contained about 4 microg of cholesterol per cubic millimeter of volume. This concentration increased to 10 to 15 microg/mm3 in the adult nucleus and decreased to about 6 microg/mm3 in the juvenile and fetal nucleus. Treatment with neither lovastatin nor simvastatin significantly altered the concentration of cholesterol in either the cortex or nuclear fractions. CONCLUSIONS: Variations in concentration of cholesterol along the radii of the lens reflect differences in the density or packing of fiber cell membranes. The observed distribution of cholesterol supports the recent model of the adult lens structure, which, from surface to center, is the cortex, adult nucleus,juvenile nucleus, fetal nucleus, and embryonic nucleus. Finding no significant changes in concentration of cholesterol in the cortex formed during treatment with lovastatin or simvastatin reinforces the results of clinical studies that indicate a high lenticular safety of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors. Nevertheless, caution is encouraged in assuming a similar ocular safety in newer drugs that inhibit cholesterol synthesis at later metabolic steps. CLINICAL RELEVANCE: Does clinical use of hypocholesterolemic drugs alter lens cholesterol?

Aged↗

PubMed1999

Prior treatment received by patients with bulimia nervosa.

OBJECTIVE: This study examined the frequency with which subjects with bulimia nervosa (BN) presenting for treatment or follow-up studies had previously received either adequate pharmacologic treatment or cognitive-behavioral therapy (CBT). METHOD: Semistructured telephone screening of individuals who called in response to advertisements about research studies was used to establish diagnoses and to clarify prior pharmacologic and psychotherapeutic treatments for BN. RESULTS: Of 581 women responding, 353 (60.8%) had probable BN. Overall, 61.4% of these subjects had received psychotherapy (96.7%) but rarely CBT (6.9%). Over one half (63.7%) had received pharmacologic treatment, most commonly with fluoxetine (72.5%). Of those having received any medication treatment, 46.2% were judged to have received at least one adequate trial. Overall, 35.0% of those previously treated had received at least one prior course of adequate pharmacotherapy or CBT for BN. CONCLUSION: Although efficacious treatments for BN have been established, they have not been received by most individuals presenting for further treatment.

Adolescent↗

PubMed1999

The relationship between rumination and eating disorders.

OBJECTIVE: Rumination has been described as a symptom in association with eating disorders, but also as a separate disorder. METHOD: A series of 8 female volunteers who reported rumination were systematically screened for the presence of eating disorders and other psychopathology. RESULTS: Seven met current or prior criteria for an Axis I disorder and five had a current or prior eating disorder. DISCUSSION: The importance of screening for eating disorders among women who ruminate, and for screening for rumination among eating disorder patients, is stressed.

Adult↗

PubMed1999

Nitrotyrosine formation in the airways and lung parenchyma of patients with asthma.

BACKGROUND: Recent evidence has shown that nitric oxide (NO) levels are increased in asthmatic airways. Although the role of NO in asthma is unknown, reactive metabolites of NO may lead to nitrotyrosine formation and promote airway dysfunction. OBJECTIVE: The aim of this study was to determine whether nitrotyrosine, as a marker of nitrating species, could be found in the airways and lung parenchyma of subjects with asthma who died of status asthmaticus or other nonrespiratory causes. METHODS: Lung tissue specimens were obtained from 5 patients who died of status asthmaticus, 2 asthmatic patients who died of nonrespiratory causes, and 6 nonasthmatic control subjects who died of nonrespiratory causes. Lung sections were stained for immunofluorescence with use of an antinitrotyrosine antibody, followed by a indiocarbocyanine (Cy5, Jackson Immunochemicals, Westgrove, Pa)-conjugated secondary antibody. RESULTS: Nonasthmatic lungs showed little or no nitrotyrosine staining, whereas asthmatic lungs demonstrated significantly more staining of nitrotyrosine residues distributed in both the airways and lung parenchyma. CONCLUSION: This study demonstrates the presence of nitrotyrosine, and hence evidence of formation of nitrating species, in the airways and lung parenchyma of patients with asthma who died of status asthmaticus or other nonrespiratory causes. This finding supports the concept that widespread airway and parenchymal inflammation occurs in asthma, and, more specifically, that NO and its reactive metabolites may play a pathophysiologic role in asthma.

Adolescent↗