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Biomedical subjects

A Boland

Publications and source records attributed to A Boland.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of the economic and environmental impact of converting cropland to forest: a case study in Dunhua county, China.

The Sloping Land Conversion Program (also known as "Grain for Green" or the Upland Conversion Program) for converting cropland to forest is one of China's most ambitious environmental initiatives, and is one of the world's largest land-conservation programs with a budget of RMB 337 billion (over US$ 40 billion). Although environmental impacts have played a vital role in the general reasoning and argumentation for forest plantations, environmental impact analyses have often received less attention than economic analyses in the planning of plantation forestry projects. The overall goal of this paper is to evaluate the program's environmental impact considering the farmer's interests and the potential social benefits due to carbon sequestration in different scenarios based on household and field survey data in Dunhua County. Our findings are that: (1) in many cases, the program did not give adequate consideration to land productivity and environmental heterogeneity when selecting plots; (2) more than half of the reforestation plots were on flat cropland (slopes of less than 5 degrees ); (3) in five of the eight townships, net incomes on reforested land were substantially above or below previous crop incomes, raising questions about the efficiency of the allocation of compensation to farmers participating in the program; (4) the potential carbon co-benefit increased the NPV of the program by 5954-7009 RMB/ha. In conclusion, we recommend that more attention should be paid to the quality of reforestation programs rather than just their scale and note that consideration of potential carbon sequestration co-benefits enhances the benefits of cropland conversion programs.

Carbon↗
PubMed2006

An integrated assessment model of carbon sequestration benefits: a case study of Liping county, China.

This research attempts to model the complexity of planting trees to increase China's CO(2) sequestration potential by using a GIS-based integrated assessment (IA) approach. We use the IA model to assess the impact of China's Grain for Green reforestation and afforestation program on farmer and state incomes as well as CO(2) sequestration in Liping County, Guizhou Province. The IA model consists of five sub-models for carbon sequestration, crop income, timber income, Grain for Green, and carbon credits. It also includes a complementary qualitative module for assessing program impacts by gender and ethnicity. Using four scenarios with various assumptions about types of trees planted, crop incomes by township, CO(2) credit prices, state subsidies, methods for estimating carbon sequestered, and harvesting of trees, we find great variation in the impact of the Grain for Green program on incomes and on carbon sequestered over a 48 year period at both the county and township levels.

Carbon↗
PubMed2006

The clinical effectiveness and cost-effectiveness of computed tomography screening for lung cancer: systematic reviews.

OBJECTIVES: The aim of this review is to examine the clinical and cost-effectiveness of screening for lung cancer using computed tomography (CT) to assist policy making and to clarify research needs. DATA SOURCES: Electronic databases and Internet resources. REVIEW METHODS: A systematic review was undertaken and selected studies were assessed using the checklists and methods described in NHS Centre for Reviews and Dissemination (CRD) Report 4. Separate narrative summaries were performed for clinical effectiveness and cost-effectiveness. Cost-effectiveness analysis resulting in a cost per quality-adjusted life-year was not feasible, therefore the main elements of such an appraisal were summarised and the key issues relating to the existing evidence base were discussed. RESULTS: Twelve studies of CT screening for lung cancer were identified, including two randomised controlled trials (RCTs) and ten studies of screening without comparator groups. The quality of reporting of these studies was variable, but the overall quality was adequate. The two RCTs were of short duration (1 year) and therefore there was currently no evidence that screening improves survival or reduces mortality. The proportion of people with abnormal CT findings varied widely between studies (5-51%). The prevalence of lung cancer detected was between 0.4% and 3.2% (number need to screen to detect one lung cancer = 31-249). Incidence rates of lung cancer were lower (0.1-1% per year). Detection of stage I and resectable tumours was high, 100% in some studies. Adverse events, as a result of investigation or surgery, or the screening process per se were poorly reported. Incidental findings of other abnormalities requiring medical follow-up were reported to be as high as 49%. Six full economic evaluations of population CT screening programmes for lung cancer were included in the review. The magnitude of cost-effectiveness ratios reported varied widely. None was set in the UK and generalisation was complicated by wide variation in the data used in different countries and a paucity of UK data for comparison. All six made the fundamental assumption that screening with CT for lung cancer reduced mortality. At the current time, there is no evidence to support that assumption. In the absence of evidence of health gains from screening for lung cancer, in terms of either quantity or quality of life, and faced with a range of uncertainties, from the frequency of abnormal screening findings within a population to the natural history of screening detected lung cancers, it is not feasible at the current time to develop accurately and meaningfully an economic argument for CT screening for lung cancer in the UK. For subgroups, in particular certain occupational groups, there is evidence of increased risk of lung cancer, but the role of screening has not been demonstrated by the current studies. CONCLUSIONS: The accepted National Screening Committee criteria are not currently met, with no RCTs, no evidence to support clinical effectiveness and no evidence of cost-effectiveness. RCTs are needed to examine the effect of CT screening on mortality, either with whole-population screening or for particular subgroups; to determine the rate of positive screening and detected lung cancers. Research is also needed to understand better the natural history and epidemiology of screening-detected lung cancers, particularly small, well-differentiated adenocarcinomas; as well as the impacts on quality of life. Increased collection is needed of UK health service data regarding resource use and safety data for lung cancer management and services. Research is also needed into the feasibility and logistics of tracing people who have in the past worked in industry where there was exposure to lung carcinogens.

Adult↗
PubMed2005

Patient and provider perspectives on home telecare: preliminary results from a randomized controlled trial.

A randomized controlled trial of home telecare for the management of acute exacerbations of chronic obstructive pulmonary disease has been undertaken in the north-west of England. A videophone was used that communicates via the ordinary telephone network. The intervention period for each participant was two weeks. Participants in the telecare arm of the trial were asked to complete logbooks to record their experiences of each telecare encounter. A simple, self-completed, 10-item questionnaire was used that consisted of a Likert scale, ranging from 1 (totally disagree) to 5 (totally agree). Fourteen nurses completed 150 logbooks and 22 patients completed 145 logbooks. These results demonstrate significant differences in perception between patients and their health-care providers with regard to telecare encounters across all the domains addressed. Participating patients consistently demonstrated more positive views of the telecare encounters than their healthcare providers.

Aged↗
PubMed2004

Newer hypnotic drugs for the short-term management of insomnia: a systematic review and economic evaluation.

OBJECTIVES: To assess the clinical and cost-effectiveness of zaleplon, zolpidem and zopiclone (Z-drugs) compared with benzodiazepines. DATA SOURCES: Electronic databases, reference lists of retrieved articles and pharmaceutical company submissions. REVIEW METHODS: Randomised controlled trials (RCTs) that compared either benzodiazepines to the Z-drugs or any two of the non-benzodiazepine drugs in patients with insomnia were included in the review. Data on the following outcome measures were considered: sleep onset latency, total sleep duration, number of awakenings, quality of sleep, adverse effects and rebound insomnia. A search was also undertaken for any study designs that evaluated issues related to adverse events (e.g. dependency and withdrawal symptoms). Full economic evaluations that compared two or more options and considered both costs and consequences including cost-effectiveness, cost-utility analysis or cost-benefit analysis undertaken in the context of high-quality RCTs were considered for inclusion in the review. RESULTS: Twenty-four studies, involving a total study population of 3909 patients, met the inclusion criteria. These included 17 studies comparing a Z-drug with a benzodiazepine and seven comparing a Z-drug with another Z-drug. The diversity of possible comparisons and the range of outcome measures in the review may be confusing. Outcomes were rarely standardised and, even when reported, differed in interpretation. In addition, variations in assessment and variety in the level of information provided make study comparisons difficult. As a result, meta-analysis has been possible on only a small number of outcomes. However, some broad conclusions might be reached based on the limited data provided. The existing published economic literature in this area is very limited. No relevant economic evaluations were identified for inclusion in the review. The industry submissions did not include detailed evidence of cost-effectiveness. Given the lack of robust clinical evidence, no economic model describing the costs and benefits of the newer hypnotic drugs for insomnia was developed. The systematic review provided in this report suggests that an agnostic approach to cost-effectiveness is required at this stage. In the short-term, no systematic evidence is available concerning significant outcome variations between either the different classes of drugs or between individual drugs within each class. Within this short-term horizon, the one element that does vary significantly is the acquisition cost of the individual drugs. CONCLUSIONS: The short-acting drugs seem equally effective and safe with minor differences that may lead a prescriber to favour one over another in different patients. There is no evidence that one is more cost-effective than any other. Analysis of the additional costs to the NHS, depending on the rate of change from benzodiazepine prescriptions to Z-drug prescriptions, at current levels of hypnotic prescribing, range from GBP2 million to GBP17 million per year. There are clear research needs in this area; in particular, none of the existing trials adequately compare these medications. It is suggested that further consideration should be given to a formal trial to allow head-to-head comparison of some of the key drugs in a double-blind RCT lasting at least 2 weeks, and of sufficient size to draw reasonable conclusions. We would also recommend that any such trial should include a placebo arm. It should also collect good-quality data around sleep outcomes and in particular quality of life and daytime drowsiness. We do not believe that any formal study of risk of dependency is feasible at present. Finally, the management of long-term insomnia is suggested for further investigation: considering the frequency of this symptom and its recurring course, the short-term trial of medication and lack of long-term follow-up undermine attempts to develop evidence-based guidelines for the use of hypnotics in this condition, or indeed for its whole management.

Adult↗
PubMed2003

Lessons from the implementation of a home telecare service.

We conducted a qualitative evaluation of the introduction of a telenursing service. The service used an analogue videophone linked with a physiological monitoring device, which allowed the transmission of data between the patient's home and the hospital. A researcher kept a detailed diary of day-to-day activity for the first year of the project. Computer software for qualitative data analysis was used to code the text and the analysis followed the principles of constant comparison. The diary entries documented how the commercially available equipment was adapted to suit the organization and content of the nurses' work. The nurses made a number of suggestions to improve the user-friendliness of the equipment. The technology, the existing home care service (the comparison arm of the study) and the randomized controlled trial itself all underwent continuous change. The traditional randomized control design of trial has limitations in this situation, and there is a need for more realistic trial designs.

Home Care Services↗
PubMed2003

A randomised controlled trial to evaluate the clinical and cost-effectiveness of Hickman line insertions in adult cancer patients by nurses.

OBJECTIVES: To examine the clinical and cost-effectiveness of image-guided Hickman line insertions versus blind Hickman line insertions undertaken by nurses in adult cancer patients. DESIGN: A cost-effectiveness analysis was carried out alongside a randomised controlled trial. SETTING: A large acute cancer centre in Manchester, UK. PARTICIPANTS: Cancer patients due to have a Hickman line insertion who were over 18 years of age and were clinically and physically compliant with specified protocols. INTERVENTIONS: In order to obtain central venous access for the patient, two interventions were investigated: (i) blind insertion of a Hickman line and (ii) image-guided insertion of a Hickman line. Both interventions involved blind venipuncture of the subclavian vein. In the blind arm, the Hickman line was routinely inserted without the use of image guidance at any point in the procedure. Transfer to the interventional X-ray suite and use of image guidance were options immediately available to the operator during the procedure if required. In the image-guided arm, the position of the guidewire was checked before the Hickman line was introduced and later the Hickman line was positioned with the use of X-ray fluoroscopy. MAIN OUTCOME MEASURES: The primary clinical outcome measure was catheter-tip misplacement and this was expected to be higher in the blind arm. When comparing the skill level of the trainer and the trainees, pneumothorax was the primary clinical outcome measure. Other outcomes measures included arterial puncture, haematoma, infection, failed insertion and assistance from other healthcare professionals. RESULTS: No statistically significant difference was found between the mean cost per patient in the two arms of the trial. The only statistically significant difference in clinical outcomes was the frequency of catheter-tip misplacement, which was higher in the blind arm of the trial. At very low costs, the image-guided approach dominates the blind approach as fewer costs and greater benefits are incurred. It is evident that nurses previously inexperienced in the procedure can be trained to insert Hickman lines successfully both at the bedside and under image guidance within a 3-month period. CONCLUSIONS: This report indicates that nurse insertion of Hickman lines in the majority of adult cancer patients is both safe and effective. However, there are a select group of patients for whom image-guided insertion may be preferred. The results reveal that skills and expertise can be transferred from trainer to trainee through a relatively short, but intensive, training course. It is also evident that patients support nurse insertion. Further research is suggested to compare the safety and efficacy of nurse versus doctor insertions in particular subgroups of patients and also to assess the quantity and quality of current service provision in order to inform NHS decision-making in this area.

Adult↗
PubMed2002

Effect of intermittent and continuous exposure to electromagnetic fields on cultured hippocampal cells.

This study was designed to assess the effect of 50 Hz electromagnetic fields (EMFs) on hippocampal cell cultures in the presence or absence of either sodium nitroprusside (SNP, a NO donor) or Fe2+ induced oxidative stress. One week old cultured rat hippocampal cells were exposed to either intermittent EMFs (IEMFs, 50 Hz, 0-5 mT, 1 min ON/OFF cycles, repeated 10 times every 2 h, 6 times/day during 48 h) or continuous EMFs (CEMFs, 50 Hz, 0-5 mT for 48 h). In a second set of experiments, the effect on such EMFs applied in combination with oxidative stress induced by 0.5 microM Fe2+ or SNP was estimated. At the end of both sets of experiments, cell mortality was assessed by lactate dehydrogenase measurements (LDH). Neither type of exposure to EMFs was observed to modify the basal rate of cell mortality. The exposure to CEMFs in presence of either NO or Fe2+ did not induce any significant increase in cell death. However, when cells were exposed to EMFs in the presence of NO, we observed a significant increase in cell death of 11 and 23% (P<0.001) at 2.5 and 5 mT, respectively. This effect had some specificity because IEMFs did not modify the effect of Fe2+ on cell mortality. Although the effects of IEMFs reported in this study were only observed at very high intensities, our model may prove valuable in trying to identify one cellular target of EMFs.

Cell Death↗
PubMed2002

Pirlindole and dehydropirlindole protect rat cultured neuronal cells against oxidative stress-induced cell death through a mechanism unrelated to MAO-A inhibition.

It has been shown that the MAO (monoamine oxidase)-B inhibitor deprenyl (DPR, selegiline) protects some cell types against oxidative stress. By decreasing H(2)O(2) production, MAO-A inhibitors could also reduce oxidative stress. This study reports the effect of the MAO-A inhibitors, pirlindole (PIR), dehydropirlindole (DHP), brofaromine (BRO) and moclobemide (MCL) on primary-cultured brain cells exposed to iron-mediated toxicity. A comparison with trolox (TRO), a hydrosoluble vitamin-E analogue that protects against such an induced stress, was performed. Rat hippocampal or cortical cultured cells were exposed either to 2 microM FeSO(4) alone or in the presence of PIR, DHP, BRO, DPR, MCL or TRO. Cell survival (lactate-dehydrogenase measurements, 16 h incubation), intracellular peroxide production (DCF-fluorescence, 1 h incubation), lipoperoxidation (TBARS-fluorescence, 6 h incubation) and mitochondrial function (MTT-test, 16 h incubation) were assessed. PIR, DHP and TRO significantly protected cultures (P<0.05) against Fe(2+)-induced toxicity in a concentration-dependent manner. The EC(50s) of these compounds were 6, 12 and 19 microM, respectively, in hippocampal cells. For cortical cell cultures incubated in the presence of iron and PIR or DHP, EC(50s) were 5 and 6 microM respectively. All Hill coefficients were close to unity. BRO, MCL and DPR were not protective in any type of culture. The IC(50s) for the inhibition of MAO-A were 2, 2 and 0.2 microM for PIR, DHP and BRO, respectively. PIR, DHP and TRO, but not DPR, induced a significant decrease in both intracellular peroxide production and lipoperoxidation. They also improved mitochondrial function. These experiments show that PIR and DHP can protect hippocampal and cortical neurons against oxidative stress at pharmacologically relevant concentrations. This protective effect seems unrelated to inhibition of MAO-A, but possibly involves free radical scavenging.

Animals↗
PubMed2002

A randomized controlled trial of home telecare.

We have established a randomized controlled trial of home telecare. The intervention aims to address a growing problem in the National Health Service (NHS), that is, high admission rates of patients with exacerbations of chronic obstructive pulmonary disease (COPD). Equipment procurement for the trial has been difficult, as no single supplier was able to meet the project s full requirements. The fact that the service is provided by existing clinical NHS staff has advantages when considering the generalizability of the results within the NHS. However, there are also disadvantages, since existing staff have little research experience. Considerable time has been required to help staff familiarize themselves with the equipment and become comfortable with its use. This has posed a barrier to the implementation of the service.

Home Care Services↗
PubMed2001

Yersinia enterocolitica YopP-induced apoptosis of macrophages involves the apoptotic signaling cascade upstream of bid.

Yersinia enterocolitica induces apoptosis in macrophages by injecting the plasmid-encoded YopP (YopJ in other Yersinia species). Recently it was reported that YopP/J is a member of an ubiquitin-like protein cysteine protease family and that the catalytic core of YopP/J is required for its inhibition of the MAPK and NF-kappaB pathways. Here we analyzed the YopP/J-induced apoptotic signaling pathway. YopP-mediated cell death could be inhibited by addition of the zVAD caspase inhibitor, but not by DEVD or YVAD. Generation of truncated Bid (tBid) was the first apoptosis-related event that we observed. The subsequent translocation of tBid to the mitochondria induced the release of cytochrome c, leading to the activation of procaspase-9 and the executioner procaspases-3 and -7. Inhibition of the postmitochondrial executioner caspases-3 and -7 did not affect Bid cleavage. Bid cleavage could not be observed in a yopP-deficient Y. enterocolitica strain, showing that this event requires YopP. Disruption of the catalytic core of YopP abolished the rapid generation of tBid, thereby hampering induction of apoptosis by Y. enterocolitica. This finding supports the idea that YopP/J induces apoptosis by directly acting on cell death pathways, rather than being the mere consequence of gene induction inhibition in combination with microbial stimulation of the macrophage.

Amino Acid Sequence↗
PubMed2000

Propofol protects cultured brain cells from iron ion-induced death: comparison with trolox.

The anesthetic propofol (PPF) has been shown to be an antioxidant in acellular experiments. This study was designed to assess the ability of PPF to protect primary-cultured brain cells against iron-mediated toxicity. A comparison with trolox (TX), a hydrosoluble vitamin E analogue, was performed. Rat cortical cells were exposed to 10 microM FeSO(4), PPF and/or TX. After a 4-h incubation, PPF and TX improved cell survival (lactate dehydrogenase measurements) in a concentration-dependent manner. The respective EC(50s) of each substance were 4 and 4.6 microM. The maximal effect was obtained at a 25-microM concentration which is similar to concentrations of PPF used clinically. The combination of both drugs at certain concentrations showed a complete protection of the cells, a significant decrease in intracellular peroxide production (dichloro-fluorescein diacetate (DCF-DA) fluorescence, 4-h incubation), in lipoperoxidation (thiobarbituric acid reactive substances fluorescence, PPF 6.25 microM+TX 12.5 microM) and an additive protective effect. This was true after 4- and 16-h incubation. These data suggest that PPF is neuroprotective. Moreover, the combination with a vitamin E analogue confers long duration protection against oxidative stress.

Animals↗
PubMed2000

Adenovirus-mediated transfer of the thyroid sodium/iodide symporter gene into tumors for a targeted radiotherapy.

The Na+/I- symporter (NIS) present in the membranes of thyroid cells is responsible for the capacity of the thyroid to concentrate iodide. This allows treatment of thyroid cancers with 131I. We propose to enlarge this therapeutic strategy to nonthyroid tumors by using an adenoviral vector to deliver the NIS gene into the tumor cells. We constructed a recombinant adenovirus encoding the rat NIS gene under the control of the cytomegalovirus promoter (AdNIS). Infection of SiHa cells (human cervix tumor cells) with AdNIS resulted in perchlorate-sensitive 125I uptake by these cells to a level 125-225 times higher than that in noninfected cells. Similar results were obtained for other human tumor cell lines, including MCF7 and T-47D (mammary gland), DU 145 and PC-3 (prostate), A549 (lung), and HT-29 (colon), demonstrating that the AdNIS vector can function in tumor cells of various origins. In addition, AdNIS-infected tumor cells were selectively killed by exposure to 131I, as revealed by clonogenic assays. To assess the efficiency of this cancer gene therapy strategy in vivo, we injected the AdNIS vector in human tumors (SiHa or MCF7 cells) established s.c. in nude mice. Immunohistological analysis confirmed the expression of the NIS protein in the tumor. Three days after intratumoral injection, AdNIS-treated tumors could specifically accumulate 125I or 123I, as revealed by kinetics and imaging experiments. A quantitative analysis demonstrated that the uptake in AdNIS-injected tumors was 4-25 times higher than that in nontreated tumors. On average, 11% of the total amount of injected 125I could be recovered per gram of AdNIS-treated tumor tissue. Altogether, these data indicate that AdNIS is very efficient in triggering significant iodide uptake by a tumor, outlining the potential of this novel cancer gene therapy approach for a targeted radiotherapy.

Adenoviridae↗
PubMed2000

Weights for waits: lessons from Salisbury.

OBJECTIVES: This paper describes a waiting list patients' points scheme under development in Salisbury, UK, for the fair management of elective inpatient and day case waiting lists. The paper illustrates how points can be assigned to patients on a waiting list to indicate their relative unmet need, and illustrates the impact on case mix and resource use of the implementations of the points system versus 'first come, first served'. The paper explores a range of philosophical and technical questions raised by the points system. METHODS: The Salisbury Priority Scoring System enables surgeons to assign relative priority to patients at the time they are placed on a waiting list for elective health care. Points are assigned to patients to reflect the rate of progress of their disease, pain or distress, disability or dependence on others, loss of usual occupation and time already waited. In recognition of the need for resource planning alongside the prioritization of elective inpatients and day case waiting lists, a range of iso-resource groups has been developed for all procedures on these lists. These categorize procedures in terms of their resource use (i.e. bed days and theatre time required). RESULTS: In a modelling exercise, application of the Salisbury Points Scheme to a 'first come, first served' orthopaedic waiting list produced considerable changes in the order of patients to be treated. Only seven patients appeared in the first 20 patients to be treated under both regimes. The Salisbury Scheme required fewer resources to treat its first 20 patients than 'first come, first served' and met more Salisbury-defined 'need', but eliminated fewer days of waiting from the list. CONCLUSIONS: Development of a points scheme and iso-resource groupings opens up opportunities for more sophisticated purchasing, based on treating patients in order of unmet need rather than according to arbitrary maximum waiting time guarantees, as has been the dominant policy on waiting lists pursued in the UK, Australia, and Sweden, to date. However, such schemes raise three issues: first, the necessity of defining need as a composite of clinical and social factors; second the necessity to determine the acceptability of explicit prioritization to both health care professionals and patients; third, the thorny issue of whether such prioritization schemes will lead to 'gaming' by well-meaning general practitioners and specialists, aiming to secure the priority of their own patients and clinical specialty. Rigorous piloting of schemes, such as that developed at Salisbury, will be required to identify their dynamic effect over time on case mix, waiting time and resource use.

Delivery of Health Care↗
PubMed1999

Activity-dependent neurotrophic factor peptide (ADNF9) protects neurons against oxidative stress-induced death.

Activity-dependent neurotrophic factor (ADNF) and a 14-amino acid fragment of this peptide (sequence VLGGGSALLRSIPA) protect neurons from death associated with an array of toxic conditions, including amyloid beta-peptide, N-methyl-D-aspartate, tetrodotoxin, and the neurotoxic HIV envelope coat protein gp120. We report that an even smaller, nine-amino acid fragment (ADNF9) with the sequence SALLRSIPA potently protects cultured embryonic day 18 rat hippocampal neurons from oxidative injury and neuronal apoptosis induced by FeSO4 and trophic factor withdrawal. Among the characteristics of this protection are maintenance of mitochondrial function and a reduction in accumulation of intracellular reactive oxygen species.

Amino Acid Sequence↗