Biomedical subjects

D Jackson

Publications and source records attributed to D Jackson.

At least 55 records · Page 3Linked to original sources

PubMed2001

Retaining a viable workforce: a critical challenge for nursing.

Nursing is facing a crisis nationally and internationall, with Australia, the United States, New Zealand, Canada, the United Kingdom and Western Europe experiencing critical shortages of nurses. Problems with recruitment, retention and an ageing workforce means that attempts to ensure a viable nursing workforce must be placed at the top of the professional agenda. Strategies currently used to manage the crisis, such as overseas recruitment, are not sustainable and are ethically dubious. The demographic timebomb is ticking and up to half the current nursing workforce will reach retirement age by 2020. It is vital that there are adequate numbers of skilled and qualified nurses to take their places. Nursing and nurses are facing unprecedented challenges and pressures in the workplace. Job satisfaction is threatened as nurses are pressured to do more with less, Nursing productivity has increased phenomenally over the past ten years in response to increased demands and decreasing numbers of staff. The nursing workplace has disturbingly high levels of occupational violence, and many nurses operate within a culture of blame and scapegoating. There is evidence that organizational change is imposed upon nurses with little or no consultation and the literature reveals that this has a direct and negative effect on job satisfaction and on retention of nurses. This paper explores some of the critical issues that nursing must confront to be successful in establishing and maintaining a vigorous, dynamic and viable workforce.

Humans↗

PubMed2000

The emergence of Streptococcus pneumoniae resistant to macrolide antimicrobial agents: a 6-year population-based assessment.

From 1994 through 1999, the available isolates (4148 isolates) from active population-based surveillance of invasive pneumococcal disease in metropolitan Atlanta were serotyped and were tested for antimicrobial susceptibility. Macrolide-resistant isolates were studied for the presence of ermAM (a ribosomal methylase gene), mefE (a macrolide efflux gene), and tetM (the class M tetracycline resistance gene). Macrolide resistance increased from 16% of all invasive isolates in 1994 to 32% in 1999. Of the macrolide-resistant pneumococcal isolates studied, 99% contained genomic copies of mefE or ermAM. Isolates with ermAM were mainly serotypes 6B, 23F, 14, or 19F and contained tetM; mefE-associated isolates were predominantly serotypes 14, 6A, or 19F, and most did not contain tetM. The frequency of the ermAM-mediated phenotype in invasive Streptococcus pneumoniae remained stable over the 6-year surveillance. However, the mefE-mediated phenotype increased from 9% in 1994 to 26% of all isolates in 1999 and was noted in new serotypes. By 1999, 93% of the mefE-containing strains had minimum inhibitory concentrations >/=8 microgram/mL. Dissemination of the mefE determinant accounted for the rapid increase in the rate of macrolide resistance in our S. pneumoniae population.

Anti-Bacterial Agents↗

PubMed2000

Day surgery for older people (70+): selection versus outcome effects.

As length of Australian hospital stays decreased, concerns were raised about benefits of shorter stays for older people. We investigated personal characteristics, perceived health outcomes (SF-36) and service use of day-only and other patients aged 70+, at one and 12 weeks after hospital discharge. Day-only patients were younger, had better self-reported health, were selected for orthopaedic, gastrointestinal and ophthalmic procedures and used similar levels of formal and informal services after discharge as people with longer stays. There was no evidence of ill effects of day surgery for older people, but improved selection and information giving procedures can improve outcomes.

Journal Article↗

PubMed2000

Epidemic nephritis in Nova Serrana, Brazil.

BACKGROUND: Outbreaks of nephritis have been rare since the 1970s. From December, 1997, to July, 1998, 253 cases of acute nephritis were identified in Nova Serrana, Brazil. Seven patients required dialysis, and three patients died. We did a case-control study to investigate the cause of the outbreak. METHODS: Using a matched cluster design, we examined seven recent patients, their family members (n=23), and members of neighbourhood-matched control households (n=22). We subsequently interviewed 50 patients and 50 matched controls about exposure to various dairy products. We also cultured dairy foods and took udder-swab and milk samples from cows. FINDINGS: Throat cultures indicated that nephritis was associated with group C Streptococcus equi subspecies zooepidemicus, a cause of bovine mastitis. S. zooepidemicus was detected in four of seven case households (six of 30 people) and no control households (p=0.09). Patients were more likely than matched controls to have consumed a locally produced cheese called queijo fresco (matched odds ratio 2.1, p=0.05). The nephritis attack rate was 4.5 per 1000 in Nova Serrana but 18 per 1000 in the village Quilombo do Gaia (p=0.003). The largest supplier of unpasteurized queijo fresco was a farm in Quilombo do Gaia. S. zooepidemicus was not detected in food samples or in swabs collected from cows in August, 1998, although mastitis was evident among cows on the suspected farm. Throat cultures of the two women who prepared cheese on this farm yielded the outbreak strain of S. zooepidemicus. After the cheese was removed from the distribution system, no further cases were reported. INTERPRETATION: A large outbreak of glomerulonephritis was attributed to S. zooepidemicus in unpasteurised cheese. This outbreak highlights the dangers of consuming unpasteurized dairy products and need for global efforts to promote food safety.

Adolescent↗

PubMed2000

Prenatal cocaine exposure alters behavioral and neurochemical sensitization to amphetamine in adult rats.

This study examined the neurochemical correlates of amphetamine (AMPH)-induced behavioral effects in prenatally saline (PSAL)-exposed or cocaine (PCOC)-exposed male rats. Pregnant Long-Evans rats received saline or saline containing cocaine hydrochloride (20 mg/kg s.c., b.i.d.) from gestational days 15-21. Animals were left with their biological mothers. Adult offspring were exposed to daily saline or AMPH (0.5, 1.5, or 5 mg/kg, i.p.) injections for 7 days. Behaviors were recorded in an open field during the first hour post-injection. PCOC rats did not exhibit behavioral anomalies during habituation to injection-stress or placement in the open field. PCOC rats displayed significant alterations in stereotyped responses to acute or intermittent exposure to various doses of AMPH. Within 48 h of the final testing day, striatal tissue was obtained from these animals and electrically-evoked [3H]acetylcholine (ACh) release was measured from striatal slices. Superfusion of tissue slices with various concentrations of AMPH (1-1000 nM) produced dose-dependent inhibition of ACh release in both PSAL and PCOC rats repeatedly injected with saline as adults. However, AMPH-induced inhibition of ACh release was decreased in PCOC rats repeatedly injected with AMPH as adults. At 5 mg/kg AMPH, PCOC rats exhibited increased mortality compared to PSAL rats. These data suggest that PCOC exposure produces long-lasting alterations in nigrostriatal transmission and behaviors mediated by this system.

Acetylcholine↗

PubMed2000

Prenatal cocaine exposure increases serotonergic inhibition of electrically evoked acetylcholine release from rat striatal slices at adulthood.

This study tests the hypothesis that prenatal cocaine (pCOC) exposure (20 mg/kg, bidaily from embryonic days 15-21) modifies 5-HT(3) receptor regulation of electrically-evoked [(3)H]acetylcholine (ACh) overflow from adult male and female (proestrus, diestrus) rat striatal slices. Also, the influence of endogenous dopamine (DA) on serotonin (5-HT) regulation of ACh overflow was determined by assessing the effects alpha-methyl-para-tyrosine (AMPT) pretreatment or sulpiride. Phenylbiguanide (PBG, 5-HT(3) agonist) superfusion dose-dependently inhibited ACh overflow in all groups except the diestrus pCOC group in which there was an enhanced sensitivity to PBG. PBG (10, 30, and 60 microM) produced greater effects in the pCOC male than in the prenatal saline (pSAL) group. The pCOC male group also exhibited greater sensitivity to PBG (30 and 60 microM) than the pCOC proestrus group. PBG inhibition of ACh overflow was comparable in the pSAL male and female (proestrus) groups. PBG inhibition of ACh overflow was greater in the pCOC diestrus group than in the pCOC proestrus (10, 30, and 60 microM), the pSAL diestrus (10 and 30 microM), and the pCOC male (10 microM) conditions. In slices from untreated rats superfused with 30 microM PBG, AMPT pretreatment (68% DA loss) reduced inhibition of ACh overflow, and 1 microM sulpiride increased ACh overflow. ICS205-930 (5-HT(3) antagonist) reduced effectiveness of PBG indicating 5-HT(3) receptor specificity for PBG. In summary, pCOC exposure enhances modulatory effects of 5-HT (via 5-HT(3) receptors) on striatal ACh release in male and females rats and the inhibitory actions of 5-HT(3) receptors are mediated by DA.

Acetylcholine↗

PubMed2000

Magnetic resonance contrast enhancement of neovasculature with alpha(v)beta(3)-targeted nanoparticles.

Site-directed contrast enhancement of angiogenic vessels in vivo was demonstrated using antibody targeting of an MRI contrast agent to the alpha(v)beta(3) integrin, a molecular marker characteristic of angiogenic endothelium. The agent was tested in a rabbit corneal micropocket model, in which neovasculature is induced in the cornea using basic fibroblast growth factor. The targeted contrast agent consists of Gd-perfluorocarbon nanoparticles linked to alpha(v)beta(3) integrin antibody DM101. The animal group receiving the targeted contrast agent displayed a 25% increase in the average MR signal intensity after 90 min. Control groups in which the nanoparticles are either used alone, linked to an isotype-matched antibody, or linked to DM101 and administered following receptor blocking did not display MR contrast enhancement at similar dose levels. These findings indicate that the antibody-targeted agent enhances MR signal intensity in the capillary bed in a corneal micropocket model of angiogenesis, and is selectively retained within the angiogenic region via specific interaction with the alpha(v)beta(3) epitope.

Animals↗

PubMed2000

Fibroblast growth factor signalling and cyclin D1 function are necessary for normal mammary gland development during pregnancy. A transgenic mouse approach.

A number of growth factors, growth factor receptors and cell cycle regulatory proteins have been implicated in the genesis of mammary carcinomas both in animal models as well as in human breast tumour samples. Studies on the development of the mammary gland has revealed that several of the proto-oncogenes, or their closely related gene-family members, have a function in the normal growth and differentiation of the gland. In this review the role of fibroblast growth factor signalling and the critical requirement for the cell cycle regulator, cyclin D1 is discussed with respect to their normal function in mammary gland development and abnormal role in mammary carcinogenesis.

Animals↗

PubMed2000

Opening up the communication channels: recent insights into plasmodesmal function.

The past year has seen significant advances in our understanding of the function and regulation of plasmodesmata. Notably, we have learned that plasmodesmata undergo dynamic changes during development and may participate in long-range communication through the transmission of RNA signals. Biochemical studies have enriched our understanding of a putative plasmodesmal receptor and of plant factors involved in viral cell-to-cell movement.

Biological Transport↗

PubMed2000

Women recovering from first-time myocardial infarction (MI): a feminist qualitative study.

Although myocardial infarction (MI) is a leading cause of death and disablement for women internationally, little is known about women's recovery. This paper describes an exploratory descriptive study that was informed by feminist principles, and which aimed to explore the recovery experiences of a group of women survivors of first-time MI in the initial period following discharge from hospital. A total of 10 female survivors were interviewed using an open-ended semi-structured interview schedule administered at 7, 14 and 21 days post-hospital discharge. Findings revealed that recovery was experienced as a complex process, initially characterized by fear and uncertainty. Over the duration of the study these feelings were replaced with a more positive outlook, a return of energy, and a sense of confidence in the future. Participants identified an unmet need for reliable information which persisted over the duration of the study. The findings of this study have implications for nursing practice and research. Chief among these is the issue of effective provision of information to women following an acute MI. The importance of providing relevant information to be understood and retained by people experiencing crisis cannot be overstated. Equally important are the provision of opportunities for patients to have regular contact with health professionals to question and seek clarifying information. These findings should now be tested on larger populations.

Adaptation, Psychological↗

PubMed2000

Environmental effects of radionuclides--observations on natural ecosystems.

To better quantify risk to non-human species from exposure to environmental radioactivity, understanding of the behaviour of radionuclides in the biosphere needs to be increased. This study outlines current thinking on ecological risk assessment (ERA) methodology and applies the indicator species or critical groups approach to biota inhabiting a semi-natural coniferous woodland contaminated with the radionuclides 137Cs, 238Pu, 239+240Pu and 241Am. The majority of these radionuclides originate from routine aerial emissions from the nuclear fuel reprocessing plant at BNFL, Sellafield, Cumbria, UK. Radionuclide activity concentrations have been determined in biota from the woodland and estimates of absorbed dose rates (mGy d(-1)) have been calculated using the dosimetric models outlined. Dose rates to the key indicator species, Oniscus asellus, Carabus violaceous and Apodemus sylvaticus (detritivorous invertebrate, predatory invertebrate and the granivorous wood mouse) have been determined at 3.0 x 10(-3) mGy d(-1), 2.2 x 10(-3) mGy d(-1) and 1.0 x 10(-3) mGy d(-1) respectively. The values are at least three orders of magnitude lower than the 1 mGy d(-1) level below which no observable effects on populations in a terrestrial ecosystem are thought to occur. Limitations of this approach are discussed.

Animals↗

PubMed2000

Radiation doses to members of the public near to Sellafield, Cumbria, from liquid discharges 1952-98.

Liquid wastes containing low levels of radioactivity have been discharged to the Irish Sea from the nuclear fuel reprocessing site at Sellafield since operations began in the early 1950s, and monitoring of radioactivity in foodstuffs has been undertaken over many years. Based on the best available monitoring data, supplemented by modelled values where necessary, doses to local critical groups have been reassessed using the most recent dosimetry. Contemporary habits data have been used where available, again supplemented by assumed habits where necessary. During the 1950s and 1960s the highest doses were received by individuals consuming Cumbrian Porphyra as laverbread, and peak doses around 0.8 to 1.0 mSv year(-1) have been estimated. During the 1970s and 1980s the critical exposure group switched to consumers of local fish and shellfish, with peak doses possibly reaching 2.5 to 3.0 mSv year(-1). Latterly, doses to all marine-related groups have declined to less than 150 to 200 microSv year(-1). At all times, doses have been within the appropriate limits set for members of the public.

Environmental Exposure↗

PubMed2000

Alpha-emitting 'hot particles' in the vicinity of BNFL Sellafield, Cumbria.

In a survey of environmental samples in the vicinity of BNFL Sellafield, two alpha-emitting radioactive particles were found in samples of grass. One particle appears to be of mineral origin, the other was not definitively identified, but may be a fragment of fuel cladding. Conservative estimates of the activities of these particles are very low. The abundance of radioactive particles in the terrestrial food chain appears to be low, with no evidence for any alpha-emitting hot particles in foodstuffs for consumption by humans. Results suggest that there is no significant dose to man through inhalation or ingestion pathways.

Alpha Particles↗

PubMed2000

The diagonal ear lobe crease (Frank's sign) is not associated with coronary artery disease or retinopathy in type 2 diabetes: the Fremantle Diabetes Study.

BACKGROUND: The diagonal ear lobe crease (ELC) has been suggested as a simple marker of vascular disease in the general population but there are few data from diabetic patients despite their increased risk of angiopathy. AIM: To determine whether the ELC is a clinically useful sign of coronary artery disease (CAD) or retinopathy in type 2 diabetes. METHODS: One thousand and twenty-two patients from the multi-ethnic urban catchment area of Fremantle Hospital in Western Australia were studied. This sample represents 79% of the type 2 diabetic subjects recruited to the ongoing Fremantle Diabetes Study and 49% of all 2072 patients with type 2 diabetes identified through active case detection in a postcode-defined region of 120,097 people. In addition to other comprehensive data relating to diabetes and its management, the presence of an ELC and evidence of both CAD and retinopathy were ascertained for each patient. RESULTS: The prevalence of ELC was 55%. Patients with an ELC were more likely to have CAD than those without an ELC (p=0.019), but the proportions with retinopathy were not significantly different (p=0.085). The sensitivity and specificity of ELC for detecting CAD were 60% and 48%, and for retinopathy 61% and 47% respectively. The patients with an ELC were significantly older, more likely to be male and had a higher systolic blood pressure than those without (p<0.02). After adjusting for known vascular risk factors, socioeconomic variables and ethnicity in a logistic regression model, an ELC was neither a significant independent predictor of CAD (p=0.45) nor of retinopathy (p=0.14). CONCLUSIONS: The ELC is of little value as a sign of the presence of diabetic vascular complications.

Adult↗

PubMed2000

The E1E4 protein of human papillomavirus type 16 associates with a putative RNA helicase through sequences in its C terminus.

Human papillomavirus type 16 (HPV16) infects cervical epithelium and is associated with the majority of cervical cancers. The E1E4 protein of HPV16 but not those of HPV1 or HPV6 was found to associate with a novel member of the DEAD box protein family of RNA helicases through sequences in its C terminus. This protein, termed E4-DBP (E4-DEAD box protein), has a molecular weight of 66,000 (66K) and can shuttle between the nucleus and the cytoplasm. It binds to RNA in vitro, including the major HPV16 late transcript (E1E4. L1), and has an RNA-independent ATPase activity which can be partially inhibited by E1E4. E4-DBP was detectable in the cytoplasm of cells expressing HPV16 E1E4 (in vivo and in vitro) and could be immunoprecipitated as an E1E4 complex from cervical epithelial cell lines. In cell lines lacking cytoplasmic intermediate filaments, loss of the leucine cluster-cytoplasmic anchor region of HPV16 E1wedgeE4 resulted in both proteins colocalizing exclusively to the nucleoli. Two additional HPV16 E1E4-binding proteins, of 80K and 50K, were identified in pull-down experiments but were not recognized by antibodies to E4-DBP or the conserved DEAD box motif. Sequence analysis of E4-DBP revealed homology in its E4-binding region with three Escherichia coli DEAD box proteins involved in the regulation of mRNA stability and degradation (RhlB, SrmB, and DeaD) and with the Rrp3 protein of Saccharomyces cerevisiae, which is involved in ribosome biogenesis. The synthesis of HPV16 coat proteins occurs after E1E4 expression and genome amplification and is regulated at the level of mRNA stability and translation. Identification of E4-DBP as an HPV16 E1E4-associated protein indicates a possible role for E1E4 in virus synthesis.

Cell Nucleus↗

PubMed2000

Can young severely disabled stroke patients regain the ability to walk independently more than three months post stroke?

OBJECTIVE: To investigate the acquisition of ability to walk independently in young severely disabled stroke patients unable to walk three months after onset. SETTING: A regional rehabilitation unit providing post-acute neurorehabilitation mainly for patients aged 16-65 years. SUBJECTS AND METHODS: A retrospective analysis of records was undertaken for 152 stroke patients admitted consecutively over a three-year period. All had a combination of physical, cognitive and language impairments; male/female 98/54; median age 54 (IQR 47-60) years. MAIN OUTCOME MEASURES: Time taken from stroke onset to regain the ability to walk safely and independently at least 5 metres around the hospital bay. RESULTS: Seventy-five (49%) regained the ability to walk independently between 3 and 11 months post onset. Patients with cognitive impairments and neglect took longer to walk. Time from stroke onset to admission was longer in patients who did not walk (median 16.3 weeks), than in those who regained walking (median 12.7 weeks; p = 0.009). Independent positive associations were found between the time taken to walk and time from onset to referral for rehabilitation (p = 0.55; p < 0.001), and time from acceptance to admission (p = 0.30; p = 0.008). CONCLUSION: With intensive specialist input, significant numbers of severely disabled young stroke patients can regain independent walking many months after onset, though late walkers may follow a slower recovery course. These results argue for investment in appropriate rehabilitation for these patients. Waiting list delays may prolong rehabilitation and potentially compromise cost effectiveness.

Activities of Daily Living↗

PubMed2000

Health status, perceptions of coping, and social support immediately after discharge of survivors of acute myocardial infarction.

BACKGROUND: The period immediately after discharge from the hospital after an acute myocardial infarction is a stressful and vulnerable time about which little is known. OBJECTIVE: To explore health status, perceptions of coping, and social support among survivors of a recent myocardial infarction in the first 3 weeks after discharge from hospitals in southwestern Sydney, Australia. METHODS: A descriptive, exploratory approach with a triangulated methodology was used to assess the experiences of 38 survivors, detect patterns in these experiences, explore the health-support needs of survivors, and determine changes in health status in the first 3 weeks after discharge. Quantitative data were collected with the Medical Outcomes Study SF-36, New York Heart Association classification, Canadian Cardiovascular Society Angina Scale, and the Jalowiec Coping Scale. A semistructured interview schedule provided additional qualitative data about the experiences of the survivors. RESULTS: The health status of participants was relatively stable during the 3-week period; most had no activity limitation due to dyspnea or angina. However, the subjects' health status was considerably lower than that of their age-matched population. The most common and most effective coping strategies adopted during this period were confrontation, optimism, and self-reliance. In addition, the subjects experienced anxiety, depression, ambiguity and uncertainty, fear of recurrence of the infarction and of deterioration in health, of boredom and of inertia. CONCLUSION: These findings can help nurses in hospital and community settings assist survivors of acute myocardial infarction to prepare for and deal effectively with experiences during convalescence.

Adaptation, Psychological↗

PubMed1999

Radionuclide behaviour and transport in a coniferous woodland ecosystem: vegetation, invertebrates and wood mice, Apodemus sylvaticus.

Activity concentrations of radionuclides (134Cs, 137Cs, 238Pu, 239 + 240Pu and 241Am) were measured in vegetation, invertebrates and wood mice, Apodemus sylvaticus, collected in Lady Wood, a coniferous woodland in the vicinity of the British Nuclear Fuels reprocessing plant at Sellafield, Cumbria, UK. Vegetation was of low diversity and biomass with activity concentrations ranging from 1 to 5 Bq kg-1 (134Cs), 0.3-0.5 Bq kg-1 (238Pu), 0.8-8 Bq kg-1 (239 + 240Pu), and 0.6-16 Bq kg-1 (241Am), dry wt. Caesium-137 activity concentrations were high compared to the reference site in Cheshire, varying between 65 and 280 Bq kg-1. Marked inter-specific and temporal differences in radionuclide activity concentrations were recorded for invertebrate populations. Caesium-137, 238Pu, 239 + 240Pu and 241Am activity concentrations in detritivorous invertebrates were consistently higher than in all other invertebrate groups reflecting contamination of the leaf litter. The activity concentrations in detritivores increased during the autumn and winter, reflecting changes in diet as food sources varied throughout the year. Activity concentrations in invertebrates caught in Lady Wood were generally an order of magnitude higher than for the reference site. Activity concentrations in wood mice varied between 7 and 150 Bq kg-1 (137Cs), 0.1-0.3 Bq kg-1 (238Pu), 0.1-0.6 Bq kg-1 (239 + 240Pu) and 0.2-0.4 Bq kg-1 (241Am). There were clear differences in the activity concentration of 137Cs (P < 0.01), 239 + 240Pu (P < 0.05) and 241Am (P < 0.05) in animals caught in Lady Wood compared to the reference site. However, the activity concentrations for 238Pu were similar at both sites, reflecting a low gastrointestinal transfer. Seasonal variation in activity concentrations was observed for 137Cs, 238Pu and 241Am. This variation is attributed to changes in the age structure of the population and diet throughout the year.

Americium↗