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Biomedical subjects

D Crawford

Publications and source records attributed to D Crawford.

At least 55 records · Page 3Linked to original sources
PubMed2000

The association between television viewing and overweight among Australian adults participating in varying levels of leisure-time physical activity.

OBJECTIVES: To investigate the effect of physical activity on the association between television viewing and overweight (body mass index (BMI) > or =25 kg/m2). DESIGN: Cross-sectional study administered by interview to adults randomly selected from the electronic white pages. SUBJECTS: 3392 adults (64% response rate) from a representative population sample in the State of New South Wales, Australia. MEASUREMENTS: Self-reported height and weight, two-week leisure-time physical activity recall, one-week average television viewing recall. RESULTS: BMI and physical activity patterns were both associated with hours of television watched. Compared to those participants who reported watching less than one hour of television per day, those watching 1 to 2.5 hours were 93% more likely to be overweight (BMI>/=25 kg/m2), those watching 2.5 to 4 hours were 183% more likely to be overweight, those watching more than 4 hours per day were four times more likely to be overweight. Physical activity was not directly associated with being overweight, but an interaction between activity and television watching was present. Respondents in the low, moderate and high physical activity categories who reported watching more than 4 hours of television per day were twice as likely to be overweight compared to those who watched less than one hour of television per day, irrespective of physical activity participation. CONCLUSIONS: With approximately half the Australian adult population overweight or obese, these findings indicate that public health strategies to reduce overweight and prevent weight gain may need to focus on reducing sedentary behaviours such as television viewing in addition to increasing physical activity.

Adolescent↗
PubMed2000

Management of obesity: attitudes and practices of Australian dietitians.

OBJECTIVE: To document attitudes and current practices of Australian dietitians in the management of overweight and obesity, and to examine their training needs. DESIGN: Cross-sectional postal survey of a randomly selected sample of members of the Dietitians Association of Australia. SUBJECTS: 400 dietitians (66% of those surveyed). MEASURES: Questionnaire-based measures of dietitian's views of obesity, education and training in weight management, definitions and perceptions of success, professional preparedness, approaches to weight management, strategies recommended for weight management, and problems and frustrations experienced. RESULTS: Dietitians viewed themselves as potential leaders in the field of weight management, and saw this area as an important part of their role. While they considered themselves to be the best-trained professionals in this area, many felt that their training was poor and many were pessimistic about intervention outcomes. Despite this, most dietitians held views that were current, and regularly employed many of the elements of known best practice in management. However, important areas of weakness included: providing opportunities for long-term follow-up; providing a range of management interventions; promoting self-monitoring of diet and exercise; and promoting opportunities for social support. CONCLUSIONS: This study suggests that training in and advocacy for the management and prevention of overweight and obesity are priority areas for dietitians, and that formal studies to evaluate dietitians' effectiveness in management should be undertaken.

Adult↗
PubMed2000

Can anyone successfully control their weight? Findings of a three year community-based study of men and women.

This study examined the prevalence, distribution and correlates of successful weight loss and successful weight maintenance over three years in a community-based sample of 854 subjects aged 20-45 at baseline. More than half (53.7%) of the participants in the study gained weight within the first twelve months, only one in four (24.5%) successfully avoided weight gain over three years, and less than one in twenty (4.6%) lost and maintained weight successfully. The findings underscore the importance of current public health efforts to prevent weight gain, and suggest that without much greater efforts to promote and support weight control the prevalence of obesity will continue to rise.

Adult↗
PubMed2000

Too fat to exercise? Obesity as a barrier to physical activity.

OBJECTIVE: To describe perceptions of being 'too fat' as a barrier to physical activity by gender and body mass index, and to examine the associations between feeling fat and other weight-related barriers to physical activity. METHODS: Analyses of cross-sectional self-report data from a representative population survey of 2,298 Australian adults. RESULTS: Overall, 4.4% of respondents reported being too fat as a barrier to physical activity; this being more common among women (6.2%), and among the obese (22.6%). Associations were found between being too fat as a barrier, and being too shy or embarrassed to exercise; being too lazy or not motivated; having an injury or disability (males only); and being not the sporty type (females only). There was no association between feeling too fat and poor health. CONCLUSIONS: Feeling too fat to exercise is a common barrier among the overweight, particularly for women. Results suggest gender differences in weight-related barriers to physical activity. IMPLICATIONS: A better understanding of the nature of weight-related physical activity barriers can help inform public health strategies designed to increase physical activity among those who are obese.

Adult↗
PubMed2000

Changes in cerebral blood flow associated with premenstrual syndrome: a preliminary study.

The purpose of this study was to determine changes in regional cerebral blood flow (rCBF) associated with premenstrual syndrome (PMS). Regional CBF was examined using single photon emission computed tomography (SPECT) in seven women who sought treatment for PMS and seven control subjects. Confirmation of PMS was based on the Daily Symptom Report (DSR) of 17 common symptoms associated with PMS. A first SPECT scan was performed near the peak of premenstrual symptoms based on DSR reports from the two previous cycles. A second scan was performed in the postmenstrual period. Prior to scanning, each subject had a Hamilton Depression Rating Scale (Ham-D) obtained. Regions of interest were drawn on the images to generate mean counts per pixel, and normalized to the cerebellum. Activity in the frontal, temporal and parieto-occipital cortices, and the thalami and basal ganglia, were compared between the two scans. Correlations between activity in each region of interest and Ham-D values were also determined. There were marked decreases in rCBF in the temporal lobes on the premenstrual scan compared to the postmenstrual scan in PMS patients. Significant correlations were observed between the change in rCBF in the right and left temporal lobes and the changes in Ham-D scores (r = 0.91, p < 0.01 and r = 0.86, p = 0.01 respectively). No rCBF changes were observed in controls. We conclude that SPECT imaging demonstrates modest decreases in rCBF in the temporal lobes that correlate with the level of depression in subjects with PMS.

Adult↗
PubMed2000

Prognostic factors in prostate cancer. College of American Pathologists Consensus Statement 1999.

BACKGROUND: Under the auspices of the College of American Pathologists, a multidisciplinary group of clinicians, pathologists, and statisticians considered prognostic and predictive factors in prostate cancer and stratified them into categories reflecting the strength of published evidence and taking into account the expert opinions of the Prostate Working Group members. MATERIALS AND METHODS: Factors were ranked according to the previous College of American Pathologists categorical rankings: category I, factors proven to be of prognostic importance and useful in clinical patient management; category II, factors that have been extensively studied biologically and clinically but whose importance remains to be validated in statistically robust studies; and category III, all other factors not sufficiently studied to demonstrate their prognostic value. Factors in categories I and II were considered with respect to variations in methods of analysis, interpretation of findings, reporting of data, and statistical evaluation. For each factor, detailed recommendations for improvement were made. Recommendations were based on the following aims: (1) increasing uniformity and completeness of pathologic evaluation of tumor specimens, (2) enhancing the quality of data collected pertaining to existing prognostic factors, and (3) improving patient care. RESULTS AND CONCLUSIONS: Factors ranked in category I included preoperative serum prostate-specific antigen level, TNM stage grouping, histologic grade as Gleason score, and surgical margin status. Category II factors included tumor volume, histologic type, and DNA ploidy. Factors in category III included perineural invasion, neuroendocrine differentiation, microvessel density, nuclear roundness, chromatin texture, other karyometric factors, proliferation markers, prostate-specific antigen derivatives, and other factors (oncogenes, tumor suppressor genes, apoptosis genes, etc).

Biomarkers, Tumor↗
PubMed1999

HLA-B15 peptide ligands are preferentially anchored at their C termini.

Therapies to elicit protective CTL require the selection of pathogen- and tumor-derived peptide ligands for presentation by MHC class I molecules. Edman sequencing of class I peptide pools generates "motifs" that indicate that nonameric ligands bearing conserved position 2 (P2) and P9 anchors provide the optimal search parameters for selecting immunogenic epitopes. To determine how well a motif represents its individual constituents, we used a hollow-fiber peptide production scheme followed by the mapping of endogenously processed class I peptide ligands through reverse-phase HPLC and mass spectrometry. Systematically mapping and characterizing ligands from B*1508, B*1501, B*1503, and B*1510 demonstrate that the peptides bound by these B15 allotypes i) vary in length from 7 to 12 residues, and ii) are more conserved at their C termini than their N-proximal P2 anchors. Comparative peptide mapping of these B15 allotypes further pinpoints endogenously processed ligands that bind to the allotypes B*1508, B*1501, and B*1503, but not B*1510. Overlapping peptide ligands are successful in binding to B*1501, B*1503, and B*1508 because these B15 allotypes share identical C-terminal anchoring pockets whereas B*1510 is divergent in the C-terminal pocket. Therefore, endogenous peptide loading into the B15 allotypes requires that a conserved C terminus be anchored in the appropriate specificity pocket while N-proximal anchors are more flexible in their location and sequence. Queries for overlapping and allele-specific peptide ligands may thus be contingent on a conserved C-terminal anchor.

Alleles↗
PubMed1999

Alpha-2 domain polymorphism and HLA class I peptide loading.

Diversity within the class I HLA antigen binding groove is positioned to moderate the presentation of peptide ligands. Polymorphism is widely dispersed about the peptide binding groove, and unravelling the functional significance of a given polymorphism requires comparative analysis of peptides presented by class I subtypes differing at the position(s) in question. Previous studies have demonstrated that not all class I polymorphisms act equally, and to determine the impact of substitutions specifically located in the alpha2 domain, peptides purified from B*1501, B*1512, B*1510, and B*1518 were examined by pooled Edman sequencing and comparative mass spectrometric analysis. Molecule B*1512 differs from B*1501 at residues 166 (Glu to Asp) and 167 (Trp to Gly) of the alpha2 domain. The pooled motif and ion mass ligand maps for B*1512 tightly matched those of B*1501, demonstrating that the 166/167 polymorphism between B*1501 and B*1512 has little impact upon ligand presentation. Although the 166/167 polymorphism minimally affects peptide binding preferences, this polymorphism makes B*1512 and B*1501 quite distinct by serology. We then compared the B70 molecules B*1510 and B*1518. The two are almost indistinguishable by serology and differ only by an alpha2 polymorphism at 116. Comparative peptide mapping shows that a Tyr to Ser polymorphism at 116 drastically changes the ligands bound by B*1510 and B*1518; no overlaps could be found. Polymorphisms in alpha2 therefore vary from subtle to extreme in the manner by which they moderate ligand presentation, and serologic crossreactivity did not reflect the ligands presented by these B15 subtypes.

Amino Acid Sequence↗
PubMed1999

Lay definitions of ideal weight and overweight.

OBJECTIVE: To describe lay definitions of ideal weight and overweight, to determine whether they correspond with current health definitions, and to examine the relationship between lay definitions and weight-control behaviour. DESIGN: Cross-sectional survey of a representative sample of adults from Victoria, Australia. SUBJECTS: 1342 men and women, aged 18 y and older from across the weight spectrum. MEASURES: Questionnaire-based measures of current height and weight to determine body mass index (BMI); weight that is considered to be ideal; weight that is considered to be overweight; current weight-control behaviour. RESULTS: The BMI at which women considered themselves to be at their ideal weight was significantly lower than that for men. For both men and women, the BMI defined as ideal increased with age and with current weight. The average BMI at which women considered themselves to be overweight was significantly lower than that for men, and was well within the acceptable BMI range. Just over two-thirds of men, defined overweight at a level higher than the current cutoff of 25 kg/m2. For both men and women, the BMI defined as overweight increased with age and with current weight. CONCLUSION: Lay definitions of ideal weight and overweight deviate substantially from health definitions. Public health initiatives should stress that many women are already a healthy weight, and encourage these women to focus their efforts on weight maintenance rather than weight loss. Since so few men have weight goals that are consistent with current health recommendations, it will be important to raise their awareness of what constitutes a healthy weight.

Adolescent↗
PubMed1999

Prognostic factors in Paget's disease of the vulva: a study of 21 cases.

Twenty-one cases of vulvar Paget's disease were studied to assess possible prognostic indicators, including presence and depth of invasion, status of resection margins, tumor DNA cell content, and immunoreactivity for p53 and estrogen receptor proteins. Immunostaining for cytokeratin 7 (CK7), cytokeratin 20 (CK20), and gross cystic disease fluid protein-15 (GCDFP) were also performed. Patients were 45 to 82 years of age (mean, 66.9 years). Ten of 21 patients (47.6%) had invasive Paget's disease. Dermal invasion was < or = 1 mm in 7 of 10 cases and 2 mm, 3 mm, and 8 mm in the remaining three invasive tumors. Of the seven patients with minimally invasive Paget's disease (< or = 1 mm depth of invasion), five are alive with no evidence of disease, one died of an unrelated illness, and one is alive with biopsy-proven in situ Paget's disease, having refused operative treatment. Of the three patients with more than minimally invasive Paget's disease (> 1 mm), all had nodal metastases; one patient is alive with no evidence of disease, one died of undertermined causes, and one died of metastatic Paget's disease. The remaining 11 patients had Paget's disease confined to the epidermis and its adnexal structures. Seven of these patients were alive at last follow-up with no evidence of disease. Of the remaining four patients, one died of metastatic cervical cancer, one died of metastatic bladder cancer, one died of an unrelated illness, and one patient is alive with biopsy-proven in situ Paget's disease and awaiting operative treatment. Twenty of the 21 cases represented primary vulvar Paget's disease while one represented possible local spread from a cervical adenocarcinoma. The immunoprofiles were GCDFP+/CK7+/CK20- in 14 cases, GCDFP+/CK7+/CK20+ in 4 cases, and GCDFP-/CK7+/CK20- in 2 cases. All tumors were estrogen receptor-negative. Immunostaining for p53 was positive in 16 tumors and negative in four tumors. Seven of 12 (58%) patients with positive margins experienced local recurrence of Paget's disease, while the disease recurred in 1 of 4 patients with negative margins. Recurrence was observed in 3 of 5 patients with diploid tumors and in 4 of 10 patients with aneuploid tumors. Neither of these differences is statistically significant. This study supports the recognition of a category of minimally invasive vulvar Paget's disease that has a low risk of distant metastasis and death caused by disease. Status of surgical resection margins, tumor cell DNA ploidy, estrogen receptor expression, and p53 immunoreactivity are not predictive of local recurrence.

Aged↗
PubMed1999

Docetaxel (Taxotere) and estramustine versus mitoxantrone and prednisone for hormone-refractory prostate cancer: scientific basis and design of Southwest Oncology Group Study 9916.

Hormone-refractory prostate cancer is the terminal step in the natural history of prostate cancer. To date, no chemotherapeutic agents have been shown to impact clinical outcome at this stage. Recently, the Food and Drug Administration approved the combination of mitoxantrone and prednisone based solely on its superior palliative effects as compared to steroids alone in 2 randomized trials. Progress in biologically driven drug development has led to the identification of several estramustine-based regimens that, although based on single institution experience, appear to have at least a comparable but very promising level of activity in hormone-refractory prostate cancer patients. One such combination, estramustine plus docetaxel (Taxotere; Rhône-Poulenc Rorer, Collegeville, PA), is particularly attractive because of its convenient schedule and side effect profile. To objectively assess the therapeutic benefit of this combination, the Southwest Oncology Group is initiating a randomized phase III trial comparing estramustine and docetaxel with the standard arm of mitoxantrone and prednisone using time to progression and survival as the primary end points. Secondary end points will include toxicity profiles, assessments of quality of life parameters, and magnitude of decline of prostate-specific antigen levels between the two treatment arms.

Adenocarcinoma↗
PubMed1998

Regional distribution of low affinity kainate receptors in brain of Macaca fascicularis determined by autoradiography using [3H](2S,4R)-4-methylglutamate.

Binding of [3H](2S,4R)-4-methylglutamate, a novel low affinity kainate receptor agonist, was studied in brain sections of a Macaca fascicularis monkey. In cerebellar sections, [3H](2S,4R)-4-methylglutamate bound to a single population of sites (KD = 20 nM) and was inhibited by various glutamate receptor ligands: kainate > 6-cyano-7-nitroquinoxaline-2,3-dione > L-glutamate >> AMPA. (S)-5-lodowillardiine and (RS)-2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl)propanoic acid (ATPA), drugs selective for the GluR5 subunit, displaced 50% and 40% of binding, respectively. Autoradiography revealed topographic binding of [3H](2S,4R)-4-methylglutamate. Binding in cortex was highest in layer 5 and restricted to CA2/3 in hippocampus. Levels of binding were high in septum and hypothalamus. Moderate densities of binding were found in caudate-putamen, cerebellar granular layer, nucleus tractus solitarius, cuneate nucleus and area postrema. Binding in spinal cord was concentrated in dorsal horn. [3H](2S,4R)-4-Methylglutamate shows differential binding throughout primate brain and is a valuable new ligand for low affinity kainate receptors.

Animals↗
PubMed1998

Weight-control practices of adults in a rural community.

Obesity is recognised as a significant public health problem, and health authorities are concerned with promoting a healthy weight for all adults. However, there is a paucity of data about community weight-control practices. We surveyed weight-control behaviour, strategies and goals in a population-based sample of 1342 adults living in rural Victoria. In addition to the 20 per cent of adults who were attempting to lose weight, 22 per cent were actively trying to maintain their present weight or to avoid weight gain. Those taking action for their weight most often did so for health-related reasons, and most of the strategies used were those recommended by health authorities. However, some adults, particularly women, adopted potentially unhealthy weight-control practices. One in four women whose weight was acceptable was trying to lose weight, and 14 per cent of women had a weight goal that was below the acceptable range. Conversely, 50 per cent of men had a weight goal higher than that currently considered acceptable. Additional research is required to assess more accurately the specific nature of community weight-control practices.

Adolescent↗
PubMed1997

The use of active noise control (ANC) to reduce acoustic noise generated during MRI scanning: some initial results.

MRI scanning generates high levels of acoustic noise that cannot only pose a safety hazard, but also impair communication between staff and patient. In this article we present active noise control (ANC) techniques that introduce antiphase noise to destructively interfere with the MRI noise and with the aim of producing a zone of quiet around the patient's ears. Using noise recorded from a 1.0 Tesla midfield MR scanner the acoustic noise generated by three standard MR imaging sequences was replayed to a real time two channel ANC system. The results obtained show a useful attenuation of low-frequency periodic acoustic noise components. Therefore, in combination with standard passive ear protection, this suggests that MR generated acoustic noise can be effectively attenuated at both low and high frequencies leading to improved patient comfort.

Acoustics↗
PubMed1997

Methylmalonic acidemia, cobalamin C type, presenting with cutaneous manifestations.

BACKGROUND: Erosive dermatitis resembling the skin lesions of acrodermatitis enteropathica has been described in a number of aminoacidopathies and organic acidemias. In some, the dermatitis is a manifestation of untreated disease, while in others, including methylmalonic acidemia, skin lesions have been ascribed to nutritional deficiency due to therapeutic amino acid restrictions. OBSERVATIONS: We report 2 cases of methylmalonic acidemia presenting with cutaneous manifestations in the perinatal period before restrictive nutritional interventions. The cutaneous involvement consisted of cheilitis and diffuse erythema with erosions and desquamation. Methylmalonic acidemia, cobalamin C type, was subsequently diagnosed in both cases. CONCLUSIONS: An erosive, desquamating dermatitis with histopathologic characteristics resembling acrodermatitis enteropathica may be a presenting sign in cobalamin C methylmalonic acidemia, even in the absence of long-standing nutritional restrictions or deficiency.

Acrodermatitis↗
PubMed1997

Mutations at the Ser50 residue of translation factor eIF-2alpha dominantly affect developmental rate, body weight, and viability of Drosophila melanogaster.

Phosphorylation of the translation initiation factor eIF-2alpha downregulates protein synthesis by sequestering the guanylate exchange factor eIF-2B. The importance of this regulation has been demonstrated in the context of stress and virally induced repression of protein synthesis but has not been investigated relative to the control of protein synthesis during development. Transgenic Drosophila strains bearing aspartic acid or alanine substitutions at the presumed regulatory phosphorylation site (Ser50) of Drosophila eIF-2alpha were established. The expression of the eIF-2alpha mutant transgenes, under the transcriptional control of the hsp70 promoter, was induced at various times during development to assess the developmental and biochemical effects. Flies bearing the aspartic acid eIF-2alpha mutant (HD) transgene displayed a slow growth phenotype and small body size. Repeated induction of the HD transgene resulted in cessation of development. In contrast, flies bearing the alanine eIF-2alpha mutant (HA) displayed a fast growth phenotype and females were significantly larger than nontransgenic control sisters. The HD transgenic flies exhibit a relatively lower level of global protein synthesis than the HA transgenic flies, although the difference is statistically insignificant.

Alanine↗