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1.
Occup Med (Lond) ; 73(8): 492-499, 2023 12 29.
Article in English | MEDLINE | ID: mdl-37948123

ABSTRACT

BACKGROUND: The impact of long-term occupational exposures on health in older adults is increasingly relevant as populations age. To date, no studies have reported their impact on survival free of disability in older adults. AIMS: We aimed to investigate the association between long-term occupational exposure and disability-free survival (DFS), all-cause mortality and cause-specific mortality in initially healthy older adults. METHODS: We analysed data from 12 215 healthy participants in the ASPirin in Reducing Events in the Elderly (ASPREE) study whose mean age was 75 years. Their work history was collated with the 'ALOHA-plus JEM' (Job Exposure Matrix) to assign occupational exposures. The primary endpoint, DFS, was a composite measure of death, dementia or persistent physical disability. The secondary endpoint, mortality, was classified according to the underlying cause. Cox proportional hazard models were used to calculate hazard ratios and 95% confidence intervals, adjusted for confounders. RESULTS: A total of 1835 individuals reached the DFS endpoint during the median 4.7 years follow-up period. Both ever-high and cumulative exposure to all dusts and all pesticides during a person's working years were associated with reduced DFS. Compared to no exposure, men with high exposure to dusts and pesticides had a reduced DFS. Neither of these exposures were significantly associated with all-cause mortality. Men with high occupational exposure to solvents and women exposed to dusts experienced higher all-cause and cancer-related mortality. CONCLUSIONS: Long-term occupational exposure to all dusts and pesticides was associated with a reduced DFS and increased mortality in community-dwelling healthy older adults.


Subject(s)
Occupational Exposure , Pesticides , Male , Humans , Female , Aged , Aspirin , Occupational Exposure/adverse effects , Dust , Risk Factors
2.
Aust Dent J ; 2023 Nov 02.
Article in English | MEDLINE | ID: mdl-37916480

ABSTRACT

OBJECTIVE: To investigate the association between oral health status and all-cause mortality in older adults using prospective cohort study design. SETTING AND PARTICIPANTS: In total, 12 809 adults aged ≥70 years (54.3% females) were participants of the ASPREE Longitudinal Study of Older Persons (ALSOP). METHODS: Participants self-reported the presence of natural teeth and oral health status. The association of self-reported oral health, edentulism and the integrative measure of the two with all-cause mortality were explored using the Cox-regression models adjusted for age, gender, socio-economic status, health-related behaviours, weight status, aspirin and polypharmacy. Hazard ratios (HRs) and 95% confidence intervals (CIs) were reported. RESULTS: In total, 22.2% of participants reported edentulism and 13.8% had fair/poor oral health. After adjustment for confounders, risk of all-cause mortality was higher among those with edentulism (vs. no edentulism) HR (95% CI) 1.43 (1.18, 1.73); and those with edentulism and reporting poor/fair oral health HR (95% CI) 1.69 (1.02, 2.82), or with no edentulism but reporting poor/fair oral health HR (95% CI) 1.46 (1.19-1.80) vs. no edentulism and reporting good/very good/excellent oral health. No association was observed between self-reported oral health alone and all-cause mortality. CONCLUSIONS: The risk of all-cause mortality was 69% higher among older adults reporting both edentulism and poor/fair oral health compared with those with teeth and more favourable self-reported oral health. © 2023 Australian Dental Association.

3.
J Nutr Health Aging ; 27(4): 301-308, 2023.
Article in English | MEDLINE | ID: mdl-37170438

ABSTRACT

OBJECTIVES: The extent to which body weight in early adulthood is associated with late-life mortality risk is unclear. This study aimed to determine the association between body mass index (BMI) in early adulthood (at 18 years of age) and older age (70 years and over), and the risk of mortality in later life. DESIGN: Secondary analysis of the ASPREE Longitudinal Study of Older Persons (ALSOP). SETTING, PARTICIPANTS: Data were from 14,853 relatively healthy community-dwelling Australians aged ≥ 70 years when enrolled in the study. MEASUREMENTS: Self-reported weight at age ≥ 70 years and recalled weight at age 18 years were collected at ALSOP study baseline. Height was measured with a stadiometer and was used for calculation of BMI at both timepoints. BMI at each timepoint was defined as: underweight, normal weight, overweight and obese. Individuals were categorised into one of five 'lifetime' BMI groups: normal weight (BMI between 18.5 and 24.9 at both times), overweight (25.0-29.9 at either or both times), obesity to non-obese (≥30.0 at age 18 and <30.0 ≥ 70 years), non-obese to obesity (<30.0 at age 18 and ≥30.0 at age ≥ 70 years), and early and later life obesity (≥30.0 at both times). RESULTS: During a median 4.7 years follow-up, 715 deaths occurred. Obesity at 18 years, but not in older age (p=0.44), was significantly associated with the risk of mortality in later life, even after accounting for current health status (HR: 2.35, 95% CI: 1.53-3.58, p<0.001). Compared with participants with normal BMI at both time points, being obese at both time points was associated with increased mortality risk (HR=1.99, 95% CI: 1.04-3.81, p=0.03), and the risk was even greater for individuals who were obese at 18 years but were no longer obese in older age (HR=2.92, 95% CI: 1.65-5.16, p<0.001), in fully adjusted models. Participants who were normal weight at 18 years and were obese in later life, did not have an increased mortality risk (p=0.78). CONCLUSIONS: Obesity in early adulthood, and obesity in both early and later life, were associated with increased mortality risk in later life. This highlights the importance of preventing obesity in early adulthood and maintaining a normal weight over an adult lifespan.


Subject(s)
Obesity , Overweight , Humans , Aged , Aged, 80 and over , Adult , Overweight/complications , Longitudinal Studies , Risk Factors , Self Report , Australia/epidemiology , Obesity/complications , Body Mass Index
4.
J Nutr Health Aging ; 27(2): 159-165, 2023.
Article in English | MEDLINE | ID: mdl-36806870

ABSTRACT

In this cross-sectional analysis of 10,071 community dwelling adults aged ≥70 years, we examined factors associated with meal skipping (self-reported) using multivariable logistic regression. Prevalence of meal skipping in this study was 19.5%. The adjusted odds (aOR [95%CI]) of meal skipping were lower in those 85+ years (vs. 70-74.9 years, 0.56 [0.45-0.70]), and in those in regional areas (vs. urban area, 0.81 [0.72-0.92]). Higher odds of meal skipping were observed for those living alone (vs. living with someone, 1.84 [1.64-2.05]), current smokers (vs. non-smokers, 2.07 [1.54-2.80]), consumers of high amounts of alcohol (vs. abstainers 1.93 [1.35-2.75]), those with poor oral health (vs. excellent oral health, 1.71 [1.07 -2.73]) diabetes (vs. not 1.26 [1.06-1.50]), or frailty (vs. not, 1.63 [1.09-2.43]). This study identified socio-demographic, social, behavioural and biomedical correlates of meal skipping in later life, which may assist in targeting interventions to address meal skipping.


Subject(s)
Feeding Behavior , Independent Living , Humans , Aged , Cross-Sectional Studies , Meals , Data Collection
5.
Public Health Nutr ; 24(2): 275-281, 2021 02.
Article in English | MEDLINE | ID: mdl-32972479

ABSTRACT

OBJECTIVE: As a result of the coronavirus-19 disease (COVID-19) pandemic, Australia adopted emergency measures on 22 March 2020. This study reports the effect of the COVID-19 lockdown on appetite and overeating in Australian adults during the first month of emergency measures. DESIGN: This study reports analysis of data from the population-based, self-completed survey. The main outcome measure was an item from the Patient Health Questionnaire 9 asking: 'Over the past 2 weeks, how often have you been bothered by poor appetite or overeating?'. Data on sociodemographic factors, symptoms of anxiety and depression, and the impact of COVID-19 and lockdown were also collected. Multivariable logistic regression was used to examine associations with poor appetite or overeating. SETTING: An anonymous online survey available from 3 April to 2 May 2020. PARTICIPANTS: A total of 13 829 Australian residents aged 18 years or over. RESULTS: The weighted prevalence of being bothered by poor appetite or overeating in the past 2 weeks was 53·6 %, with 11·6 % (95 % CI 10·6, 12·6) of the cohort reporting poor appetite or overeating nearly every day. High levels of anxiety, concern about contracting COVID-19, being in lockdown with children and reporting a severe impact of the lockdown were associated with increased odds of poor appetite or overeating. CONCLUSIONS: Given the widespread prevalence of being bothered by poor appetite or overeating, universal public health interventions to address emotion-focused or situational eating during periods of lockdown may be appropriate.


Subject(s)
Appetite , COVID-19/epidemiology , Hyperphagia/epidemiology , Adolescent , Adult , Aged , Anxiety/epidemiology , Australia/epidemiology , Depression/epidemiology , Female , Humans , Logistic Models , Male , Middle Aged , Pandemics , Prevalence , SARS-CoV-2 , Socioeconomic Factors , Surveys and Questionnaires , Young Adult
6.
Vision Res ; 141: 303-316, 2017 12.
Article in English | MEDLINE | ID: mdl-28283347

ABSTRACT

A factor analysis was performed on 25 visual and auditory performance measures from 1060 participants. The results revealed evidence both for a factor relating to general perceptual performance, and for eight independent factors that relate to particular perceptual skills. In an unrotated PCA, the general factor for perceptual performance accounted for 19.9% of the total variance in the 25 performance measures. Following varimax rotation, 8 consistent factors were identified, which appear to relate to (1) sensitivity to medium and high spatial frequencies, (2) auditory perceptual ability (3) oculomotor speed, (4) oculomotor control, (5) contrast sensitivity at low spatial frequencies, (6) stereo acuity, (7) letter recognition, and (8) flicker sensitivity. The results of a hierarchical cluster analysis were consistent with our rotated factor solution. We also report correlations between the eight performance factors and other (non-performance) measures of perception, demographic and anatomical measures, and questionnaire items probing other psychological variables.


Subject(s)
Visual Perception/physiology , Adolescent , Adult , Auditory Perception/physiology , Cluster Analysis , Contrast Sensitivity/physiology , Depth Perception/physiology , Eye Movements/physiology , Factor Analysis, Statistical , Female , Humans , Male , Personality/physiology , Space Perception/physiology , Vision, Binocular/physiology , Visual Acuity/physiology , Young Adult
7.
Vision Res ; 110(Pt A): 34-50, 2015 May.
Article in English | MEDLINE | ID: mdl-25771401

ABSTRACT

As part of a genome-wide association study (GWAS) of perceptual traits in healthy adults, we measured stereo acuity, the duration of alternative percepts in binocular rivalry and the extent of dichoptic masking in 1060 participants. We present the distributions of the measures, the correlations between measures, and their relationships to other psychophysical traits. We report sex differences, and correlations with age, interpupillary distance, eye dominance, phorias, visual acuity and personality. The GWAS, using data from 988 participants, yielded one genetic association that passed a permutation test for significance: The variant rs1022907 in the gene VTI1A was associated with self-reported ability to see autostereograms. We list a number of other suggestive genetic associations (p<10(-5)).


Subject(s)
Vision, Binocular/physiology , Adult , Age Factors , Aged , Contrast Sensitivity/physiology , Dominance, Ocular/physiology , Female , Genome-Wide Association Study , Humans , Male , Middle Aged , Perceptual Masking/physiology , Psychophysics , Sensory Thresholds , Sex Factors , Vision Disparity/physiology , Vision, Binocular/genetics , Visual Acuity/physiology , Visual Perception/genetics , Visual Perception/physiology , Young Adult
8.
J Opt Soc Am A Opt Image Sci Vis ; 31(4): A226-31, 2014 Apr 01.
Article in English | MEDLINE | ID: mdl-24695174

ABSTRACT

The OSCAR test, a clinical device that uses counterphase flicker photometry, is believed to be sensitive to the relative numbers of long-wavelength and middle-wavelength cones in the retina, as well as to individual variations in the spectral positions of the photopigments. As part of a population study of individual variations in perception, we obtained OSCAR settings from 1058 participants. We report the distribution characteristics for this cohort. A randomly selected subset of participants was tested twice at an interval of at least one week: the test-retest reliability (Spearman's rho) was 0.80. In a whole-genome association analysis we found a provisional association with a single nucleotide polymorphism (rs16844995). This marker is close to the gene RXRG, which encodes a nuclear receptor, retinoid X receptor γ. This nuclear receptor is already known to have a role in the differentiation of cones during the development of the eye, and we suggest that polymorphisms in or close to RXRG influence the relative probability with which long-wave and middle-wave opsin genes are expressed in human cones.


Subject(s)
Genotype , Phenotype , Photometry/methods , Retinal Cone Photoreceptor Cells/cytology , Adolescent , Adult , Artifacts , Female , Genomics , Humans , Male , Polymorphism, Single Nucleotide , Reproducibility of Results , Retinal Cone Photoreceptor Cells/metabolism , Retinoid X Receptor gamma/genetics , Young Adult
9.
J Opt Soc Am A Opt Image Sci Vis ; 31(4): A357-64, 2014 Apr 01.
Article in English | MEDLINE | ID: mdl-24695194

ABSTRACT

If unique hues have special status in phenomenological experience as perceptually pure, it seems reasonable to assume that they are represented more precisely by the visual system than are other colors. Following the method of Malkoc et al. (J. Opt. Soc. Am. A22, 2154 [2005]), we gathered unique and binary hue selections from 50 subjects. For these subjects we repeated the measurements in two separate sessions, allowing us to measure test-retest reliabilities (0.52≤ρ≤0.78; p≪0.01). We quantified the within-individual variability for selections of each hue. Adjusting for the differences in variability intrinsic to different regions of chromaticity space, we compared the within-individual variability for unique hues to that for binary hues. Surprisingly, we found that selections of unique hues did not show consistently lower variability than selections of binary hues. We repeated hue measurements in a single session for an independent sample of 58 subjects, using a different relative scaling of the cardinal axes of MacLeod-Boynton chromaticity space. Again, we found no consistent difference in adjusted within-individual variability for selections of unique and binary hues. Our finding does not depend on the particular scaling chosen for the Y axis of MacLeod-Boynton chromaticity space.


Subject(s)
Color Perception Tests , Color Perception , Adolescent , Adult , Female , Humans , Male , Photic Stimulation , Young Adult
10.
Genes Brain Behav ; 13(2): 144-51, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24152035

ABSTRACT

Deficits in sensitivity to visual stimuli of low spatial frequency and high temporal frequency (so-called frequency-doubled gratings) have been demonstrated both in schizophrenia and in autism spectrum disorder (ASD). Such basic perceptual functions are ideal candidates for molecular genetic study, because the underlying neural mechanisms are well characterized; but they have sometimes been overlooked in favor of cognitive and neurophysiological endophenotypes, for which neural substrates are often unknown. Here, we report a genome-wide association study of a basic visual endophenotype associated with psychological disorder. Sensitivity to frequency-doubled gratings was measured in 1060 healthy young adults, and analyzed for association with genotype using linear regression at 642 758 single nucleotide polymorphism (SNP) markers. A significant association (P = 7.9 × 10(-9) ) was found with the SNP marker rs1797052, situated in the 5'-untranslated region of PDZK1; each additional copy of the minor allele was associated with an increase in sensitivity equivalent to more than half a standard deviation. A permutation procedure, which accounts for multiple testing, showed that the association was significant at the α = 0.005 level. The region on chromosome 1q21.1 surrounding PDZK1 is an established susceptibility locus both for schizophrenia and for ASD, mirroring the common association of the visual endophenotype with the two disorders. PDZK1 interacts with N-methyl-d-aspartate receptors and neuroligins, which have been implicated in the etiologies of schizophrenia and ASD. These findings suggest that perceptual abnormalities observed in two different disorders may be linked by common genetic elements.


Subject(s)
Autistic Disorder/genetics , Chromosomes, Human, Pair 21/genetics , Phenotype , Polymorphism, Single Nucleotide , Schizophrenia/genetics , Visual Acuity/genetics , Adolescent , Adult , Alleles , Autistic Disorder/physiopathology , Carrier Proteins/genetics , Female , Genome-Wide Association Study , Humans , Male , Membrane Proteins , Schizophrenia/physiopathology
11.
Clin Exp Pharmacol Physiol ; 36(7): 643-7, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19076166

ABSTRACT

1. Diabetes is a significant risk factor for cardiovascular disease (CVD), but the presence of comorbidities, such as hypertension, markedly increases CVD risk. The aim of the present study was to determine the effectiveness of hypertension management in patients with diabetes. 2. The cvTRAC Study was a cross-sectional study of CVD risk factors in primary care practices across Australia. General medical practitioners enrolled patients they considered to be at increased risk of CVD and reported on cardiovascular disease history, CVD risk factor levels and current therapy. 3. In all, 9857 men and 8332 women with diabetes participated in the study, with > 85% having at least two CVD risk factors in addition to diabetes and 68% having a history of hypertension. Lost therapeutic benefit in diabetes patients with hypertension was seen in those who were failing to meet targets on antihypertensive drug therapy (therapeutic inertia: > 73% of the hypertensive cohort), with a smaller proportion accounted for by those who met prescribing guidelines but were not being treated pharmacologically (treatment gap: 5.4% of the hypertensive cohort). Lack of compliance with lifestyle guidelines was estimated to account for over 8% of those not meeting blood pressure targets. Age (odds ratio (OR) 0.983, 95% confidence interval (CI) 0.980-0.986; P < 0.001), compliance with physical activity guidelines (OR 1.219, 95% CI 1.088-1.366; P = 0.001) and compliance with dietary guidelines (OR 1.298, 95% CI 1.188-1.420; P < 0.001) were independent predictors of target blood pressure attainment in the diabetic population. 4. Deficiencies in pharmacological and lifestyle-related therapeutic strategies contribute to suboptimal hypertension management in diabetes. Therapeutic inertia is a greater contributor to lost therapeutic benefit than treatment gap in this population.


Subject(s)
Blood Pressure/physiology , Cardiovascular Diseases/physiopathology , Diabetes Mellitus, Type 2/physiopathology , Hypertension/physiopathology , Aged , Antihypertensive Agents/pharmacology , Antihypertensive Agents/therapeutic use , Blood Pressure/drug effects , Cardiovascular Diseases/etiology , Cardiovascular Diseases/prevention & control , Cohort Studies , Cross-Sectional Studies , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/drug therapy , Disease Management , Female , Humans , Hypertension/drug therapy , Hypertension/etiology , Male , Middle Aged , Risk Factors , Risk Reduction Behavior
12.
Eur J Clin Nutr ; 59(2): 304-6, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15508016

ABSTRACT

OBJECTIVE: Levels of vitamin E have been reported to be lower in patients suffering major depression, but whether this is due to inadequate dietary intake or the pathophysiology of depression is not known, and was the subject of the present study. SETTING: Wollongong, Australia. METHODS: Plasma vitamin E (alpha-tocopherol) was measured in 49 adults with major depression, age (mean+/-s.d.): 47+/-12 y. In a subset (n=19) usual dietary intake of vitamin E was determined by diet history. RESULTS: Subjects had significantly lower plasma alpha-tocopherol (4.71+/-0.13 mumol/mmol cholesterol) than has previously been reported for healthy Australians, and plasma alpha-tocopherol was inversely related to depression score (by Beck Depression Inventory) (r=-0.367, P<0.009). Diet analysis indicated that 89% of subjects met or exceeded the recommended intake for vitamin E, and dietary intake was not related to plasma alpha-tocopherol level in this subset. CONCLUSION: These findings suggest that plasma levels of alpha-tocopherol are lower in depression, but this is not likely to be the result of inability to meet recommended dietary intake. .


Subject(s)
Depression/etiology , Vitamin E Deficiency/blood , Vitamin E/administration & dosage , Vitamin E/blood , Adult , Aged , Antioxidants/metabolism , Australia/epidemiology , Biomarkers/blood , Depression/blood , Depression/epidemiology , Female , Humans , Male , Middle Aged , Nutritional Requirements , Severity of Illness Index , alpha-Tocopherol/blood
13.
J Commun Disord ; 34(4): 323-37, 2001.
Article in English | MEDLINE | ID: mdl-11508898

ABSTRACT

UNLABELLED: Phonological deficits are common in children with specific language impairment (SLI). However, the degree to which they constitute an area of extraordinary difficulty, and their contribution to the morphological deficits of these children are largely unknown. In this investigation, we studied a group of young children with SLI who were acquiring Hebrew, a language in which phonology and morphology are closely linked. The phonology of these children lagged behind that of same-age peers as well as younger normally developing children matched according to mean number of morphemes per utterance. Furthermore, the children with SLI were more likely to commit phonological errors that neutralized important morphological distinctions in their language. These findings have implications for both assessment and therapy. LEARNING OUTCOMES: As a result of this activity, the following learning outcomes will be achieved: The participant will be able to: (1) describe the differences in phonology between children with SLI and typically developing children; (2) describe the impact ofphonological disorders on the assessment of the morphological systems of children with SLI; and (3) explain the necessary modifications to a therapy program for children with a combination of morphological and phonological disorders.


Subject(s)
Language Disorders/diagnosis , Language , Linguistics , Speech/physiology , Verbal Behavior , Child, Preschool , Humans , Phonetics , Severity of Illness Index
15.
J Drug Target ; 7(2): 79-99, 1999.
Article in English | MEDLINE | ID: mdl-10617295

ABSTRACT

This review discusses pulmonary delivery of glucocorticoids and cyclosporine in pharmaceutically acceptable organic solvents and liposomes, as well as in micellar solutions and microemulsions, by means of liquid aerosols generated by nebulizers. The review points out the importance of a variety of parameters for successful treatment of immunologically mediated lung diseases by inhalation of drug containing aerosols with particular references to physico-chemical properties of formulations, aerosol parameters, pharmacokinetics, and lung deposition in experimental animals and humans. The prospects for the use of these types of formulations for clinical treatment of asthma, lung transplant rejection processes and other lung diseases are summarized.


Subject(s)
Chemistry, Pharmaceutical/methods , Cyclosporine/administration & dosage , Glucocorticoids/administration & dosage , Lung Diseases/drug therapy , Nebulizers and Vaporizers/standards , Administration, Inhalation , Aerosols , Animals , Clinical Trials as Topic , Cyclosporine/pharmacokinetics , Drug Delivery Systems/standards , Glucocorticoids/pharmacokinetics , Humans , In Vitro Techniques , Liposomes/pharmacokinetics , Solubility
16.
J Drug Target ; 5(6): 443-58, 1998.
Article in English | MEDLINE | ID: mdl-9783676

ABSTRACT

The review deals with the preparation, properties, and analysis of different kinds of cyclosporine delivery systems, such as solid formulations, liposomes, emulsions and microemulsions and targeted cyclosporine formulations. The review points out a key role of delivery systems in increasing the therapeutic effectiveness of cyclosporine. Comparative studies of the prior marketed formulation, Sandimmune, with a new microemulsion formulation, Neoral, are discussed including some data on clinical development of Neoral.


Subject(s)
Cyclosporine/administration & dosage , Drug Delivery Systems , Cyclosporine/pharmacokinetics , Drug Carriers , Emulsions , Humans , Liposomes
17.
Can J Microbiol ; 43(6): 561-8, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9226875

ABSTRACT

In a laboratory-scale system, dentrification activity of a heterotrophic microbial starter culture changed when different lots of poly-3-hydroxybutyrate-co-3-hydroxyvalerate (P(HB-co-HV)) were used as the solid carbon source in the heterotrophic denitrification reactor. In this study, possible influences of physical and chemical properties of commercially produced P(HB-co-HV) (Biopol) on biofilm formation and metabolic activity of a denitrifying starter culture were investigated. These parameters indicate the polymers' suitability for the application as the matrix substance in the bioreactor. No differences in microstructure were detected between the different lots of polymers. Growth inhibitory effects by chemical additives were found in the case of triacetine, which was included as a plasticizer in seven of eight tested lots. The amount of hydroxyvaleric acid in the polymer was not assumed to affect denitrification activity. Relevant differences could be detected regarding primary adhesion of the starter culture Pseudomonas sp. strain 2nIII. It showed good adsorption properties to hydrophobic substances with a dependence on precultivation conditions. Pseudomonas sp. strain 2nIII degraded poly-3-hydroxybutyrate acid homopolymer and P(HB-co-HV) copolymers but was unable to break up poly-3-hydroxyvaleric acid. A possible reason for these findings is the substrate specifity of the polyhydroxyalkanoate depolymerase.


Subject(s)
Polyesters/metabolism , Pseudomonas/metabolism , Adsorption , Aerobiosis , Biodegradation, Environmental , Biofilms/growth & development , Bioreactors , Microscopy, Electron, Scanning , Nitrogen/metabolism , Plasticizers , Pseudomonas/growth & development , Pseudomonas/ultrastructure , Titanium , Water Microbiology , Water Supply/analysis
18.
Pediatr Surg Int ; 12(1): 49-53, 1997.
Article in English | MEDLINE | ID: mdl-9035210

ABSTRACT

Migration of particulate matter from plastic tubing and solid plastic implants has been documented in a number of studies, including some with the use of cardiac bypass, haemodialysis, and pump-assisted intravenous infusions. In order to ascertain whether silicone embolisation occurs when children have an Ivac 560 pump-assisted IV infusion, we passed 180 ml of pumped fluid through a microfilter and compared the scanning electron micrographs of those filters with unused filters and with others through which a similar volume had been passed without using the pump. The particles on the filters were analysed for their elemental content using energy-dispersive X-ray analysis. In addition, the appearance of the silicone tubing used in the pump over 3 and 72 h was assessed and compared to that of flow-only and unused tubing. More particles were found on the microfilter when fluid had been delivered via the pump than on those through which non-pumped fluid had passed or that were unused. Elemental silicon-containing particles were only found on the filter when a pump had been attached to the IV line. The flow-only and unused tubing were found to have adherent particles on the inner surface that were not seen once the tubing had been used for 3 h in the Ivac 560 pump. Also, after 72 h use, the silicone tubing had a deformed inner layer. The clinical significance of these findings is yet to be determined, but it does appear that silicone embolisation occurs during pump-assisted infusions in children.


Subject(s)
Infusion Pumps , Infusions, Intravenous/instrumentation , Silicones , Biocompatible Materials , Cellulose/analogs & derivatives , Child , Electron Probe Microanalysis , Embolism/etiology , Filtration , Foreign Bodies/etiology , Humans , In Vitro Techniques , Membranes, Artificial , Microscopy, Electron, Scanning , Time Factors
19.
Brain Res ; 770(1-2): 115-22, 1997 Oct 03.
Article in English | MEDLINE | ID: mdl-9372210

ABSTRACT

Brief periods of global cerebral ischemia are known to produce characteristic patterns of neuronal injury both in human studies and in experimental animal models. Ischemic damage to vulnerable areas such as the CA1 sector of the hippocampus is thought to result from excitotoxic amino acid neurotransmission. The objective of this study was to determine the ability of a novel sodium channel blocking compound, zonisamide, to reduce neuronal damage by preventing the ischemia-associated accumulation of extracellular glutamate. Using a gerbil model, animals were subjected to 5 min ischemic insults. Both pre- and post-ischemic drug administration (zonisamide 150 mg/kg) were studied. Histological brain sections were prepared using a silver stain at 7 and 28 days post ischemia. The animals sacrificed at 28 days also underwent behavioral testing using a modified Morris water maze. In vivo microdialysis was performed on a separate group of animals in order to determine the patterns of ischemia-induced glutamate accumulation in the CA1 sector of the hippocampus. Pyramidal cell damage scores in the CA1 region of the hippocampus were significantly reduced in animals pre-treated with zonisamide compared to saline-treated controls, both at 7 days (drug pre-treated: 0.812 +/- 0.28, n = 8; controls: 1.625 +/- 0.24, n = 8; *P < 0.05) and 28 (drug pre-treated: 0.833 +/- 0.22, n = 12; controls: 1.955 +/- 0.26, n = 11; **P < 0.01) days post ischemia. However, animals receiving zonisamide post-treatment did not display significant differences from controls. Behavioral studies also showed significant preservation of function in drug-treated animals. Microdialysis studies confirmed a reduction in glutamate release in drug-treated animals compared to saline-treated controls. Our data suggest that zonisamide is effective in reducing neuronal damage by a mechanism involving decreased ischemia-induced extracellular glutamate accumulation and interruption of excitotoxic pathways.


Subject(s)
Anticonvulsants/pharmacology , Ischemic Attack, Transient/drug therapy , Isoxazoles/pharmacology , Neuroprotective Agents/pharmacology , Prosencephalon/blood supply , Animals , Behavior, Animal/physiology , Disease Models, Animal , Gerbillinae , Glutamic Acid/metabolism , Hippocampus/blood supply , Hippocampus/pathology , Hippocampus/physiopathology , Male , Maze Learning/physiology , Microdialysis , Prosencephalon/pathology , Prosencephalon/physiopathology , Silver Staining , Zonisamide
20.
Biochem Biophys Res Commun ; 216(3): 778-84, 1995 Nov 22.
Article in English | MEDLINE | ID: mdl-7488193

ABSTRACT

Stabilisation of the catalytic transition state by long-range charge interactions has been tested with mutagenesis for porcine pancreatic phospholipase A2. Electrostatics calculations were used to determine locations which would interact preferentially with one part of the dipolar charge separation that is believed to develop in the transition state. Experiment shows increased enzyme activity relative to wild-type recombinant enzyme for mutants N97D and N101D, consistent with the design.


Subject(s)
Pancreas/enzymology , Phospholipases A/metabolism , Animals , Binding Sites , Electrochemistry , Enzyme Stability , Micelles , Models, Molecular , Molecular Structure , Mutagenesis, Site-Directed , Phospholipases A/chemistry , Phospholipases A/genetics , Phospholipases A2 , Recombinant Proteins/metabolism , Swine
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