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Biomedical subjects

B Harvey

Publications and source records attributed to B Harvey.

At least 19 recordsLinked to original sources
PubMed2002

Toxicity of fumonisin from Fusarium verticillioides culture material and moniliformin from Fusarium fujikuroi culture material when fed singly and in combination to growing barrows.

The effects of fumonisin B1 (FB1) from Fasarium verticillioides culture material and moniliformin from Fusarum fujikuroi culture material on growing barrows were evaluated. Four groups of six barrows (three replicates of two each; mean body weight, 11.1 kg) were fed diets containing 0 mg of FB1 and 0 mg of moniliformin per kg of feed (control), 100 mg of FB1 per kg of feed, 100 mg of moniliformin per kg of feed, and 100 mg of FB1 plus 100 mg of moniliformin per kg of feed. Barrows were fed these diets for 28 days. Body weight gain, feed efficiency, serum biochemical analytes, and hematological values were adversely affected by the FB1 and the FB1-plus-moniliformin diets. The moniliformin diet decreased body weight gain. Two barrows in the moniliformin diet group died, and two barrows in the FB1-plus-moniliformin diet group died. All deaths occurred during the first 6 days of the study. Mild to moderate lesions were observed microscopically in heart and lung tissues of the groups fed moniliformin and FB1 plus moniliformin and in liver tissues of the groups fed FB1 and FB1 plus moniliformin. Except for the acute mortality associated with the two diets containing moniliformin. clinical disease induced by the combined feeding of these two mycotoxins appears to be additive or less than additive and due primarily to the toxic expression of FB1.

Animal Feed↗
PubMed2001

Determining the need for hip and knee arthroplasty: the role of clinical severity and patients' preferences.

BACKGROUND: Area variation in the use of surgical interventions such as arthroplasty is viewed as concerning and inappropriate. OBJECTIVES: To determine whether area arthroplasty rates reflect patient-related demand factors, we estimated the need for and the willingness to undergo arthroplasty in a high- and a low-use area of Ontario, Canada. RESEARCH DESIGN: Population-based mail and telephone survey. SUBJECTS: All adults aged > or =55 years in a high (n = 21,925) and low (n = 26,293) arthroplasty use area. MEASURES: We determined arthritis severity and comorbidity with questionnaires, established the presence of arthritis with examination and radiographs, and evaluated willingness to have arthroplasty with interviews. Potential arthroplasty need was defined as severe arthritis, no absolute contraindication for surgery, and evidence of arthritis on examination and radiographs. Estimates of need were then adjusted for patients' willingness to undergo arthroplasty. RESULTS: Response rates were 72.0% for questionnaires and interviews. The potential need for arthroplasty was 36.3/1,000 respondents in the high-rate area compared with 28.5/1,000 in the low-rate area (P <0.0001). Among individuals with potential need, only 14.9% in the high-rate area and 8.5% in the low-rate area were definitely willing to undergo arthroplasty (P = 0.03), yielding adjusted estimates of need of 5.4/1,000 and 2.4/1,000 in the high- and low-rate areas, respectively. CONCLUSIONS: Demonstrable need and willingness were greater in the high-rate area, suggesting these factors explain in part the observed geographic rate variations for this procedure. Among those with severe arthritis, no more than 15% were definitely willing to undergo arthroplasty, emphasizing the importance of considering both patients' preferences and surgical indications when evaluating need and appropriateness of rates for surgery.

Activities of Daily Living↗
PubMed2000

Differences between men and women in the rate of use of hip and knee arthroplasty.

BACKGROUND: Previous studies suggest that, for some conditions, women receive fewer health care interventions than men. We estimated the potential need for arthroplasty and the willingness to undergo the procedure in both men and women and examined whether there were differences between the sexes. METHODS: All 48,218 persons 55 years of age or older in two areas of Ontario, Canada, were surveyed by mail and telephone to identify those with hip or knee problems. In these subjects, we assessed the severity of arthritis and the presence of coexisting conditions by questionnaire, documented arthritis by examination and radiography, and conducted interviews to evaluate the subjects' willingness to undergo arthroplasty. The potential need for arthroplasty was defined by the presence of severe symptoms and disability, the absence of any absolute contraindications to surgery, and clinical and radiographic evidence of arthritis. The estimates of need were then adjusted for the subjects' willingness to undergo arthroplasty. RESULTS: The overall response rates were at least 72 percent for the questionnaires and interviews. As compared with men, women had a higher prevalence of arthritis of the hip or knee (age-adjusted odds ratio, 1.76; P<0.001) and had worse symptoms and greater disability, but women were less likely to have undergone arthroplasty (adjusted odds ratio, 0.78; P<0.001). Despite their equal willingness to have the surgery, fewer women than men had discussed the possibility of arthroplasty with a physician (adjusted odds ratio, 0.63). The numbers of people with a potential need for hip or knee arthroplasty were 44.9 per 1000 among women and 20.8 per 1000 among men. After adjustment for willingness to undergo the procedure, the numbers were 5.3 per 1000 for women and 1.6 per 1000 for men. CONCLUSIONS: There is underuse of arthroplasty for severe arthritis in both sexes, but the degree of underuse is more than three times as great in women as in men.

Aged↗
PubMed2000

Operation Safe Haven: an evaluation of health surveillance and monitoring in an acute setting.

From May to June 1999, 3,920 ethnic Albanians from Kosovo arrived in Australia as part of Operation Safe Haven. These people were evacuated from refugee camps in the former Yugoslav Republic of Macedonia. Initial processing in Australia occurred at East Hills Reception Centre, and accommodation for the duration of stay was provided in eight Haven Centres in five States. The arrival of a large number of refugees in a short time frame is unprecedented in Australia. A health surveillance system was developed and critical health data were collected to assess health status and needs, plan care, monitor for potential outbreaks of communicable diseases, track service use, to meet international reporting requirements and document our response to this crisis. In this article the health surveillance system is evaluated and suggestions are offered for the formulation of specific guidelines necessary for health surveillance in acute settings.

Acute Disease↗
PubMed2000

Role of pericytes in vascular calcification: a review.

Pericytes are defined by their location in vivo; the pericyte partially surrounds the endothelial cell of the microvessel and shares a common basement membrane with it. As an integral part of the microvasculature, pericytes play a fundamental role in maintaining local and tissue homeostasis. Current evidence also suggests that pericytes function as progenitor cells capable of differentiating into a variety of different cell types including osteoblasts, chondrocytes and adipocytes. It is now apparent that cells resembling microvascular pericytes, and termed 'pericyte-like' cells, have a widespread distribution in vivo. Pericyte-like cells have been identified in the inner intima, the outer media, and in the vasa vasora of the adventitia of large, medium and small human arteries (1, 2). Moreover, recent studies have suggested that these cells may be responsible, at least in part, for mediating the calcification commonly associated with atherosclerosis (1, 3, 4). In this review, we a) examine the evidence that microvascular pericytes deposit a bone-like mineralised matrix in vitro, b) compare the morphological and biochemical properties of microvascular pericytes, calcifying vascular cells (CVCs) and 'classical' smooth muscle cells (SMCs) isolated from bovine aorta, c) demonstrate that microvascular pericytes deposit a well-organised matrix of bone, cartilage and fibrous tissue in vivo, and d) discuss recent studies designed to gain a better understanding of how pericyte differentiation is regulated.

Animals↗
PubMed2000

Cigarette smoking in multicultural, urban high school students.

PURPOSE: To profile patterns of cigarette use among a multiethnic population of high school students, and identify important factors associated with cigarette use by ethnicity, in order to plan effective health promotion strategies. METHODS: This cross-sectional study involved the completion of a lifestyle questionnaire by 1236 Grade 9-13 students (86% response rate) from 62 randomly selected classrooms in three urban high schools in Toronto. Chi-square analysis of the association between tobacco use and other variables took account of the clustered sample using CSAMPLE in Epi Info. RESULTS: The students self-identified their ethnicity as follows: 388 Canadian, 269 European, 171 East Indian, 137 Asian, 76 West Indian, and 194 "other." Students who identified themselves as Canadians were significantly more likely to be current smokers (29%) than students reporting other ethnicities (13%). There was no apparent increase in smoking rates for immigrants after 2 or more years in Canada. Current drinking, sexual activity, and especially friends smoking was most strongly associated with current smoking for most ethnic groups, although the relative importance of these variables was not identical for all groups. CONCLUSIONS: Prevention programs may benefit from a focus on the influence of peer smoking and on the grouping together of lifestyle factors associated with smoking for students in all ethnic groups in this multicultural city.

Adolescent↗
PubMed2000

Characterization of a Mycobacterium smegmatis mutant that is simultaneously resistant to D-cycloserine and vancomycin.

A mutant of Mycobacterium smegmatis has been isolated that is simultaneously resistant to both D-cycloserine (D-CS) and vancomycin. Genetic complementation with a PBP4 homolog restores sensitivity to both drugs. Resistance to D-CS and vancomycin in this mutant is most likely due to a novel mechanism involving peptidoglycan assembly at the cell surface.

Amino Acid Sequence↗
PubMed2000

Evaluation of a drama-in-education programme to increase AIDS awareness in South African high schools: a randomized community intervention trial.

A community intervention trial was undertaken in KwaZulu Natal, South Africa to evaluate the effectiveness of a high school drama-in-education programme. Seven pairs of secondary schools were randomized to receive either written information about HIV/AIDS or the drama programme. Questionnaire surveys of knowledge, attitude and behaviour were compared before and 6 months after the interventions. One thousand and eighty students participated in the first survey and 699 in the second. Improvements in knowledge (P=0.0002) and attitudes (P < 0.00001) about HIV/AIDS were demonstrated in pupils at schools receiving the drama programme when compared to pupils receiving written information alone. These changes were independent of age, gender, school or previous sexual experience. In schools receiving the drama programme, sexually active pupils reported an increase in condom use (P < 0.01). It is important to provide resources to sustain such programmes and to obtain stronger evidence of effect on behaviour by measuring changes in HIV incidence.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Establishment and characterization of adenoviral E1A immortalized cell lines derived from the rat suprachiasmatic nucleus.

Primary cultured cells from the presumptive anlage of the rat suprachiasmatic nucleus (SCN) were immortalized by infection with a retroviral vector encoding the adenovirus 12S E1A gene. After drug selection, the resulting neural cell lines (SCN1.4 and SCN2.2) displayed (a) extended growth potential without evidence of transformed or tumorigenic properties, (b) expression of E1A protein within all cell nuclei, and (c) heterogeneous cell types in various stages of differentiation. A large proportion of the SCN1.4 and SCN2.2 cells were characterized by gliallike morphologies, but showed limited expression of corresponding cell type-specific antigens. In addition, both lines exhibited a stable population of cells with neuronlike characteristics. When treated so as to enhance differentiation, these cells were often distinguished by fine, long processes and immunocytochemical expression of neuronal markers and peptides found within SCN neurons in situ. Observations on SCN neuropeptide immunostaining, content, release, and mRNA expression followed a concordant pattern in which somatostatin and vasopressin cells were the most and least common peptidergic phenotypes in both lines, respectively. Since these results indicate that constituents of E1A-immortalized lines derived from the primordial SCN can differentiate into cells with phenotypes resembling parental peptidergic neurons, it will be critical to explore next whether these lines also retain the distinctive function of the SCN to generate circadian rhythms. Cloning of immortalized cell types could subsequently yield useful tools for studying the development of SCN glial and peptidergic cell types and delineating their distinct roles in mammalian circadian time-keeping.

Adenovirus E1A Proteins↗
PubMed1999

Alcohol use beliefs and behaviors among high school students.

PURPOSE: To identify specific alcohol use beliefs and behaviors among local high school students; to determine whether relationships exist between alcohol use and various sociodemographic and lifestyle behaviors; and to assist in the development and implementation of alcohol abuse prevention programs. METHODS: This cross-sectional study involved the completion of a questionnaire by 1236 Grade 9-13 students (86% response rate) from 62 randomly selected classrooms in three Canadian urban schools. Data analyzed here are part of a larger lifestyle survey. RESULTS: A total of 24% of students reported never having tasted alcohol, 22% have tasted alcohol but do not currently drink, 39% are current moderate drinkers, 11% are current heavy drinkers (five or more drinks on one occasion at least once a month), and 5% did not answer. Reasons stated most often for not drinking were "bad for health" and "upbringing," while reasons stated most often for drinking were "enjoy it" and "to get in a party mood." Student drinking patterns were significantly related to gender, ethnicity, grade, and the reported drinking habits of parents and friends. Older male adolescents who describe their ethnicity as Canadian are at higher risk for heavy drinking than students who are younger or female, or identify their ethnicity as European or Asian. Current heavy drinkers are at higher risk than other students for engaging in other high-risk behaviors such as drinking and driving, being a passenger in a car when the driver is intoxicated, and daily smoking. CONCLUSIONS: Heavy alcohol use in adolescents remains an important community health concern. Older self-described Canadian and Canadian-born male adolescents are at higher risk for heavy drinking. Current and heavy drinking rises significantly between Grades 9 and 12. Students who drink heavily are more likely to drink and drive, to smoke daily, and to have friends and parents who drink alcohol.

Adolescent↗
PubMed1999

Altering the fat content affects flavor release in a model yogurt system.

Flavored yogurts differing in fat content were eaten, and the release of flavor volatiles was measured by monitoring the volatile composition of air from the nose in real time by atmospheric pressure ionization mass spectrometry. Low-fat yogurts (0.2%) were found to release volatiles more quickly and at higher intensity but with less persistence than yogurts containing fat at 3.5 and 10% fat. Yogurts with increasing fat content had higher viscosity and lower relative particle size. Lipophilic compounds were more affected by fat for maximum volatile intensity, but not time-to-maximum intensity or persistence. Sensory assessment of the yogurts found significant differences in intensity and speed of onset of flavor, but not overall length of perception.

Animals↗
PubMed1999

Surveillance of acute flaccid paralysis in Australia, 1995-97. Australian Paediatric Surveillance Unit.

OBJECTIVE: Acute flaccid paralysis (AFP) surveillance in Australia as part of the World Health Organization (WHO) certification process for polio eradication in the Western Pacific region. METHODS: Active monthly AFP surveillance through the Australian Paediatric Surveillance Unit, from March 1995 to December 1997. RESULTS: Based on 80 cases, the reported overall rate of AFP was 0.73 per 10(5) children < 15 years (below the expected 1 per 10(5)). The major causes of AFP were Guillain-Barré syndrome (51%) and transverse myelitis (19%). According to the WHO virological classification, there was no case of poliomyelitis, 37.5% were 'non-polio' and 62.5% cases were 'polio compatible' due to inadequate stool testing and follow-up. However, case review by an expert panel enabled 95% to be classified as 'non-polio'. CONCLUSION: Australia must improve AFP surveillance to confirm absence of wild poliovirus. Paediatricians can help Australia meet its certification requirements and contribute to the global eradication effort by reporting and investigating all cases of AFP.

Adolescent↗
PubMed1999

The T7 concatemer junction sequence interferes with expression from a downstream T7 promoter in vivo.

A recently described new signal for transcription termination in vitro by T7 RNA polymerase has now been tested in vivo. This signal, identified during transcription of the cloned human preproparathyroid hormone (PTH) gene, is also found in the phage T7 genome, at the concatemer junction (CJ). We introduced the 17-bp concatemer junction sequence at the ends of a test gene and control gene (both derived from T7 gene 9) in a T7 vector previously used to study effects of rare codons on expression. The CJ elements replaced the original vector's RNase III processing sites, and a new T7 promoter was also introduced to drive the downstream (control) gene. We assayed for test and control gene mRNA and protein by direct labeling with [32P]phosphate and [35S]methionine. The altered vector with CJ sequences (pCT1.1) expressed the upstream test gene, but showed poor expression of the downstream control gene. No discrete T7 mRNA bands could be discerned by direct labeling with 32P. A precursor vector with only the control gene in single copy expressed the protein much better, suggesting that the inhibition of control gene expression in pCT1.1 was a result of the upstream CJ element at the 3' end of the test gene. RT-PCR experiments were consistent with readthrough and possibly pausing at CJ. An RNA folding program predicts a highly stable secondary structure between the upstream CJ element and the control gene's translation start signals. These data support an interpretation that the CJ element is ineffective as a T7 transcription terminator in vivo in this vector, and that structure of the readthrough transcript blocks ribosome access to the downstream translation start. The readthrough transcripts are also likely to be less stable than properly terminated or processed T7 mRNA, because levels of test protein expression in pCT1.1 were reduced compared to original vector, and basal expression was negligible, while the original codon test vector shows substantial basal expression.

Bacteriophage T7↗
PubMed1998

Tuberculosis notifications in Australia, 1996. Communicable Diseases Network Australia New Zealand.

Since the implementation of the National Mycobacterial Surveillance System (NMSS) in 1991, the epidemiology and trends of tuberculosis in Australia have been described in a series of annual reports. This article presents an analysis of the data for tuberculosis notifications for 1996. A total of 1,037 notifications of tuberculosis were received for the year 1996, and the crude rates of new and relapsed disease were reported at 5.37 per 100,000 and 0.29 per 100,000 respectively. Rates of tuberculosis have remained stable over the last decade and the majority of notifications and highest rates of disease continue to occur in the overseas-born population.

Adolescent↗
PubMed1998

Pertussis vaccines: past, present and future in Australia.

In August 1997, a workshop was convened by the National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases to consider current issues in the use of pertussis vaccines and implications for the Australian immunisation schedule. Topics covered included the history, efficacy and reactogenicity of whole-cell and acellular vaccines and vaccine schedules. Acellular pertussis vaccine is preferred by the National Health and Medical Research Council for the primary course as well as the 18 month and 4-5 year old childhood doses. At the time of the workshop, a 3-component acellular vaccine (DTPa) had been approved (licensed) in Australia for all doses in the childhood schedule. It was the first vaccine subject to a cost-effectiveness evaluation under the new vaccine funding arrangements. Issues considered in the evaluation of the cost-effectiveness of the vaccine were discussed. These included comparative efficacy, adverse events and compliance, and the question of community as well as individual benefit from the use of the vaccine.

Australia↗