bluuebunny/crossref_metadata_2025 huggingface dataset:
Profitability of incremental generic promotion of Australian dairy products
Authors: Hill D.J. , Piggott R.R. , Griffith G.R.
Published: August 2005

The motivation for this study rests on two factors. First, Australian dairy farmers spend around $20 million annually on generic promotion and estimates of the returns from this expenditure are required to facilitate efficient investment decisions. Second, while the Australian dairy industry has been highly regulated, there has been a substantial reduction in assistance over the past decade and farm‐gate milk prices were deregulated on 1 July 2000. The profit potential of promotion may vary with the degree of regulation, so past estimates of the returns from promotion may not hold in the competitive environment of the future. Hence, the aim of this study is to examine the effects of government intervention on the profitability for dairy farmers of incremental changes in generic dairy promotion expenditure using a perfectly competitive market as a reference point. Competitive market price and quantity outcomes for the Australian dairy industry are estimated. The impacts of increments in dairy product and competing product generic promotion expenditures on dairy farmers’ profits are assessed using equilibrium displacement modelling. Finally, graphical procedures are used to examine the effects of dairy industry regulation on the profitability of dairy promotion.
Factors explaining the diffusion of hybrid maize in Latin America and the Caribbean region
Authors: Kosarek Jennifer L. , Garcia Philip , Morris Michael L.
Published: August 2005

If future demand for maize in Latin America and the Caribbean region (LAC) is to be met from local sources, domestic production must continue to increase. Because further expansion in the area planted to maize is precluded by the limited availability of arable land, future increases in production will have to rely heavily on the spread of productivity‐enhancing hybrid technology. Until now, the diffusion of hybrid maize in LAC has been quite variable. Using data from 18 countries, we investigate factors affecting the hybrid maize diffusion rate. Our findings validate conventional profitability‐based explanations of producer adoption behavior, but they also confirm the importance of supply‐side factors, thereby providing empirical support for the life cycle theory of seed industry development. We conclude that if policy makers in LAC are to accelerate the diffusion of hybrid maize, they will have to ensure an environment in which it is not only profitable for producers to adopt improved germplasm, but also profitable for the seed industry to produce and sell high‐quality seed.
Attribution and other problems in assessing the returns to agricultural R&D
Authors: Alston Julian M. , Pardey Philip G.
Published: August 2005

Estimated rates of return to research are distorted by problems of attributing the credit for particular research results, or for particular research‐induced productivity increases, among research expenditures undertaken at different times, in different places, and by different agencies. A comprehensive assessment of the evidence from past economic evaluations of the returns to agricultural R&D indicates that studies generally report high rates of return, with enormous variation among studies, but that much of this evidence has been tainted by inadequate attention to attribution problems. This paper raises these concerns in a general way and illustrates their importance with reference to two particular types of attribution problem. First, we consider the problem of accounting for locational spillovers in attributing varietal‐improvement technology among research performers, using US wheat varieties as an example. Second, we consider the temporal aspects of the attribution problem using the specification of research lags in econometric models to illustrate the problem of attributing aggregate productivity gains to research expenditures made at different times.
Economic analysis of environmental benefits of integrated pest management: a Philippine case study
Authors: Cuyno Leah C.M. , Norton George W. , Rola Agnes
Published: August 2005

Health and environmental concerns associated with pesticide use have motivated the development of integrated pest management (IPM) programs around the world. Little empirical work has been completed to estimate the value of the environmental benefits of IPM. This paper provides an approach to evaluate a broad set of such benefits for a vegetable program in the Philippines. Assessments were made of (1) IPM‐induced reduction in environmental risks posed by pesticides in onion production in the Central Luzon and (2) willingness to pay to reduce those risks. The latter was based on a contingent valuation (CV) interview survey of 176 farmers. Risks to humans, birds, aquatic species, beneficial insects, and other animals were considered. IPM practices on onions reduced the use of specific pesticides from 25 to 65%, depending on the practice, and the projected adoption of IPM practices varied from 36 to 94%. Estimated economic benefits varied from 231 to 305 pesos per person per cropping season (40 pesos = 1 US$). The aggregate value of environmental benefits for the five villages where the IPM research program was centred was estimated at 150,000 US$ for the 4600 local residents. Assessment of environmental benefits can help in designing public policies and regulations, and in justifying support for publicly funded IPM programs.
Infrastructure and rural development: insights from a Grameen Bank village phone initiative in Bangladesh⋆
Authors: Bayes Abdul
Published: August 2005

The intention of the present paper is to evaluate the role of telecommunications within the contexts of rural development in general and of poverty reduction in particular. Bangladesh has been selected as a case study due to the uniqueness it displayed in an innovative program for expanded telecom infrastructure, in which Grameen Bank (GB) of Bangladesh, the village‐based micro‐finance organisation, leased cellular mobile phones to successful members. GB calls these phones village pay phones (VPPs). The effects of VPPs are assessed from two angles: sellers of services (telephone lessees/owners) and buyers of services (villagers). The findings of the study lead to two basic conclusions: first, pursuance of pragmatic policies can turn telephones into production goods, especially through lowering transaction costs, and second, the services originating from telephones in villages are likely to deliver (even) more benefits to the poor than to the non‐poor. The VPPs also seem to have perceptible and positive effects on the empowerment and social status of phone‐leasing women and their households. For villagers in general, phones offer additional non‐economic benefits such as improved law enforcement, more rapid and effective communications during disasters, stronger kinship bonding, etc. GB's style of managing communications can help significantly to expand access to this vital information input for all segments of the population, reduce inequality and thus enhance the broad‐based, pro‐poor orientation of rural development activities.
Averting a food crisis: private imports and public targeted distribution in Bangladesh after the 1998 flood
Authors: Ninno Carlo del , Dorosh Paul A.
Published: August 2005

The 1998 flood in Bangladesh caused a shortfall of 2.2 million tonnes (mill.t) in the rice production and threatened the food security of tens of millions of households. Despite the best efforts of donors and the government, the public distribution of rice and wheat was only 188,000t more than originally planned for July 1998 to April 1999.

However, a major food crisis was averted as private imports, made possible by trade liberalisation in the early 1990s, stabilised market prices and supplies. The government's direct distribution programs, though small compared to private imports, nonetheless increased access to food by poor households. Household survey data indicate that immediate relief efforts were well targeted to flood‐affected households, as were transfers from NGOs. Vulnerable Group Feeding (VGF). a medium‐term program, was not targeted well to households directly exposed to the flood, though the program was relatively well targeted to poor households.

More broadly, the Bangladesh experience with the 1998 flood shows that in a liberalised trade regime, where private imports respond to price signals, food aid's contribution to the total availability of food may be minimal. However, foreign assistance in kind or in cash, can provide resources for subsidised, targeted distribution to food‐insecure households ‐ assistance not possible otherwise under tight government budget constraints.
The economic cost of the CAP revisited
Authors: Philippidis G. , Hubbard L.J.
Published: August 2005

This paper reports estimates of the domestic economic cost of the common agricultural policy (CAP) from computable general equilibrium simulations which incorporate imperfect competition in the non‐primary sectors, as well as explicit modelling of agricultural protection. Imperfect competition is characterised to include hierarchical preferences, addressing the notion of varietal diversity as an important decision variable in consumer behaviour. Results indicate that repeal of the CAP would reduce varietal diversity in food processing in the EU, causing utility losses. However, these would be countered by positive varietal effects in other sectors and by strong allocative effects. The net cost of the CAP to the EU is estimated at 0.2% of gross domestic product (GDP). For an individual member state the cost can be considerably larger, as with the UK where the estimate is above 0.5% of GDP.
Grain transport and rural credit in Mozambique: solving the space–time problem
Authors: Arndt Channing , Schiller Rico , Tarp Finn
Published: August 2005

This paper shows how credit market failures can lead to large welfare losses in grain markets by inducing increased transport for seasonal storage in locations with low credit costs. The burden of these welfare losses falls primarily on rural households. These conclusions are obtained from a spatial/temporal model solved using a mixed complementarity formulation that easily handles interest rate differentials across space. Efforts to address credit market failures and to improve the efficiency of rural storage should be given priority as opposed to the creation of large, formal sector grain collection centers.
Evolution of land tenure institutions and development of agroforestry: evidence from customary land areas of Sumatra
Authors: Otsuka Keijiro , Suyanto S. , Sonobe Tetsushi , Tomich Thomas P.
Published: August 2005

It is widely believed that land tenure insecurity under a customary tenure system leads to a socially inefficient resource allocation. This article demonstrates that the practice of granting secure individual ownership to tree planters spurs earlier tree planting, which is inefficient from the private point of view but could be efficient from the viewpoint of the global environment. Regression analysis, based on primary data collected in Sumatra, indicates that an expected increase in tenure security in fact led to early tree planting. It is also found that customary land tenure institutions have been evolving towards greater tenure security responding to increasing scarcity of land.
Modeling the impact of technological change on nutrition and marketed surplus
Authors: Ahmed Mohamed M. , Preckel Paul V. , Baker Timothy G. , Lopez‐Pereira Miguel
Published: August 2005

This study develops and demonstrates procedures for modeling the impact of agricultural technology adoption decisions on consumption and nutrition in a subsistence‐farming context. The method is based on expected direct utility maximization (EDUM) formulation and incorporates subsistence quantities for broad aggregates of protein, calories, and other consumption goods. The method is applied to a hillside farming system of southern Honduras where new sorghum cultivars and erosion control techniques are being introduced.

The expected direct utility maximization model allows the estimation of the effects of new technology on consumption and marketed surplus in situations where marginal values of products vary by state of nature and are affected by consumption and production choices. The introduction of the new technologies in southern Honduras results in improved nutrition and substantial increases in marketed surplus. These effects are due to simultaneous changes in output and consumption patterns. This work extends the subject of household modeling to problems with risk, and thus complements prior work in both the integrated analysis of production/consumption decisions and stochastic decision analysis.
Combining results of different models: the case of a levy on the Dutch nitrogen surplus
Authors: Polman Nico B.P. , Thijssen Geert J.
Published: August 2005

Economic instruments, such as levies are considered by the Dutch government for reducing the harmful effects of the production and application of manure. To analyse these levies a framework which makes it possible to combine and to choose among different types of research is developed. The results are integrated along the line of the marginal abatement cost curve. The problems related to integrating different types of research are taken into account. The method developed allows every farmer to react to a levy differently. A levy turns out to be more effective to reduce the nitrogen surplus on farm level in the pig fattening sector when compared to the pig breeding sector. But even a levy of 2 guilderd/kg of nitrogen does not remove the total manure surplus in the pig sector and results in large profit losses. Further research is needed to underpin the empirical input required by the model.
Deforestation and land use change: sparse data environments
Authors: Nelson Gerald C. , Geoghegan Jacqueline
Published: August 2005

Understanding determinants of land use in developing countries has become a priority for researchers and policy makers with a wide range of interests. For the vast majority of these land use issues, the location of change is as important as its magnitude. This overview paper highlights new economic approaches to modeling land use determinants that combine non‐traditional data sources with novel economic models and econometric techniques. A key feature is that location is central to the analysis. All data elements include an explicit location attribute, estimation techniques include the potential for complications from spatial effects, and results are location‐specific. The paper reviews the theory underlying these models. Since this paper is intended to provide the potential new researcher with an introduction to the challenges of this analysis, we present an overview of how remotely‐sensed data are collected and processed, describe key GIS concepts and identify sources of data for this type of econometric analysis. Finally, selected papers using these techniques are reviewed.
Crossing spatial analyses and livestock economics to understand deforestation processes in the Brazilian Amazon: the case of São Félix do Xingú in South Pará
Authors: Mertens B. , Poccard‐Chapuis R. , Piketty M.‐G. , Lacques A.‐E. , Venturieri A.
Published: August 2005

The Amazon is the largest tropical forest area on Earth, and has been undergoing rapid deforestation for the last four decades. In the Brazilian Amazon, large‐scale pasture for cattle ranching and soybean production are the main land uses, leading to a yearly deforestation rate of 0.5%. These conversions are mostly located in frontier areas distributed along the so‐called “arc of deforestation”. Within this large zone, various land use change processes are interacting through several modes of land valuation and organisation. From several case studies in the State of Pará (Brazil), the current project aims at analysing how landscape dynamics are related to infrastructure development, ecological conditions, zoning policies and to the evolution and the organisation of the production, consumption and marketing chains of livestock products. This paper presents the results for one test site, the region of São Félix do Xingú, South of Pará This region is the focus of land speculation, cattle expansion, and deforestation. Road construction, investments in electrical energy, financial credit for cattle, and the land reform policies have all fuelled this process. All these factors make this region one of the most dynamic agricultural frontiers in the Brazilian Amazon. The main objective of the paper is to improve our understanding of deforestation processes by crossing spatial analyses and 1ivestock economics.studies, and to characterise the role and impact of various natural and anthropic factors in the location and development of the main types of farmers, and their policy implications.
The dynamics of land‐cover change in western Honduras: exploring spatial and temporal complexity
Authors: Munroeaic Darla K. , Southworth Jane , Tucker Catherine M.
Published: August 2005

This paper presents an econometric analysis of land‐cover change in western Honduras. Ground‐truthed satellite image analysis indicates that between 1987 and 1996, net forest regrowth occurred in the 1015 km2study region. While some forest regrowth can be attributed to a 1987 ban on logging, the area of forest regrowth greatly exceeds that of previously clear‐cut areas. Further, new area was also deforested between 1987 and 1996. Thus, the observed land‐cover changes most likely represent a complex mosaic of changing land‐use patterns across time and space. Using satellite imagery from 1987, 1991 and 1996, we estimate a series of models, including binary probit models for each date, and a random‐effects probit model using panel techniques. We also experiment with spatial sampling schemes designed to reduce residual spatial autocorrelation, and qualitatively compare the impact of spatial sampling on model accuracy. Lastly, we find that changes in relative prices, infrastructure improvement, and topography are all significantly related to changing land‐cover patterns.
Capturing household‐level spatial influence in agricultural management using random effects regression
Authors: Swinton Scott M.
Published: August 2005

Data on agricultural and natural resource management typically have spatial patterns related to the landscapes from which they came. Consequently, econometric models designed to explain the determinants of humans' natural resource management practices or their outcomes often have spatial structure that can bring bias or inefficiency to parameter estimates.

Although econometric tools are available to correct for spatial structure, such tools are largely lacking for use with discrete dependent variable models. While one obvious solution would be to develop the necessary tools, an alternative is to identify conditions under which spatial dependency can be managed effectively without formal spatial autoregressive models.

This study examines conditions under which spatial structure corresponds closely to defined agro‐ecological zones, making it possible to model spatial effects by random effects regression. Using household survey data sampled along agro‐ecological zone strata, this article develops two models of links between farmer assets and agricultural natural resource degradation in southern Peru. The first stage model looks at determinants of crop yield loss over time (an index of soil productivity), while the second stage model looks at determinants of the extent of fallow cycles in crop rotation, a key agricultural practice reducing crop yield loss.

Diagnostic statistics for spatial dependency reveal spatial structure, particularly in the fallow model. This spatial dependency is eliminated in the ordinary least squares (OLS) models by inclusion of the agro‐ecological zone random effects. In the spatially dependent fallow model, comparison of coefficient estimates between OLS and the spatial autoregressive maximum likelihood models showed OLS with random effects to give virtually identical results to the spatial autoregressive models, making the latter unnecessary.

These results show that spatial structure in natural resource management models can sometimes be captured by zonal variables. When this occurs, random effects regression can largely eliminate spatial dependency. A necessary precondition for this approach with household survey data is prior sample stratification according to landscape characteristics. Where random effects models can effectively capture spatial structure, they may also offer analysts greater flexibility in analyzing models with limited dependent variables.
Bayesian spatial probit estimation: a primer and an application to HYV rice adoption
Authors: Holloway Garth , Shankar Bhavani , Rahmanb Sanzidur
Published: August 2005

Increasingly, spatial econometric methods are becoming part of the standard toolkit of applied researchers in agricultural, environmental and development economics. Nonetheless, applications in discrete‐choice settings remain few and despite its appeal, applications of the Bayesian paradigm in these settings are still fewer. We provide a primer to the Bayesian spatial probit with the objective of making accessible to non‐users a class of iterative estimation methods that have become fairly routine in Bayesian circles, offer an extremely powerful addition to applied researchers toolkits, and are essential in Bayesian implementation of spatial econometric models. We demonstrate the methods and apply them to estimate the ‘neighbourhood effect’ in high‐yielding variety (HYV) adoption among Bangladeshi rice producers. We estimate the strength of this relationship using a standard, spatial probit model and compare the policy conclusions with and without the neighbourhood effect included.
Spatial economics of biological control: investing in new releases of insects for earlier limitation of Paterson's curse in Australia
Authors: Nordblom T.L. , Smyth M. J. , Swirepik A. , Sheppard A.W. , Briese D.T. ,   Cooperative Research Centre for Australian Weed Management (Weeds CRC)
Published: August 2005

Paterson's curse and related weeds (Echium spp.) were introduced as garden flowers before 1850 and have spread to over 30 million ha in southern Australia. Four hundred successful releases of crown weevil (M. lawatus) populations specifically targeting Echium spp. were made in the 1993–2000 period. Based on the timing, location and performance of these past releases of beneficial insects, spatially and temporally specific trajectories of biocontrol have been simulated. Insect populations established by the past releases are expected to cover expanding areas at densities sufficient to limit host Echium infestations only over the next 25‐50 years. The present analysis tackles the questions of where and how many additional releases are economically justified to speed up this process. We identify 31 districts in which diminishing niches for further insect releases are projected over time, according to the locations of damaging weed infestations and the timing, location and numbers of past insect releases. Benefits of biocontrol are expressed in terms of the value of recovered pasture productivity, keyed to estimates of loss and to historical district livestock inventories converted to dry sheep equivalent (DSE) feed availability levels to which prices are applied. Expected marginal contributions of increments of new releases were simulated for each of the 31 districts, subject to the spacehime limitations of each niche. Our explicit accounting for the spatial and temporal dimensions has made possible the economically optimd targeting of new biocontrol releases. For example, at $12/DSE and a marginal cost of $2000 per release, with a discount rate of l0%, we find there is a case for a program of over 400 new releases targeted to 17 districts, with as few as five releases to each of several and as many as 70 releases in one district.
The effect of Emdogain® on ectopic bone formation in tubes of rat demineralized dentin matrix
Authors: Koike Yoshihiko , Murakami Satoshi , Matsuzaka Kenichi , Inoue Takashi
Published: August 2005

Background:  Emdogain® (EMD) is made from enamel matrix proteins (EMPs) from the tooth germ of swine and propylene glycol alginate (PGA) as a matrix. The function of EMD is known to differentiate cells of the dental follicle into cementoblasts. However, little is known about the effect of EMD on mesenchymal cells in other tissue.

Objective:  The purpose of this study was to investigate whether EMD has the ability to induce hard tissue when applied with or without demineralized dentin matrix.

Methods:  Half of the dentin tubes prepared from rat incisors were demineralized by treatment with 0.6 N hydrochloric acid for 3 h. EMD or PGA was injected into the demineralized or non‐demineralized dentin tubes, which were then transplanted into rectus abdominis muscles. Untreated dentin tubes were also transplanted as a control. Animals were killed at 7, 14 and 21 days after the implantation.

Results:  Non‐demineralized dentin tubes with or without EMD or PGA did not form any hard tissue. In the demineralized group, chondrogenesis in the PGA groups occurred earlier than in the EMD groups. The expression of vascular endothelial growth factor (VEGF) mRNA in the demineralized group with PGA at day 14 was the highest. The expression of osteopontin and osteocalcin mRNAs was higher in all groups at 21 days compared with 7 or 14 days.

Conclusion:  These results suggest that neither EMD nor PGA has the ability to induce hard tissue and that EMPs contained within EMD might aggregate on the dentin surface and inhibit the effect of the demineralized dentin matrix.
Differential effects of estrogen on DNA synthesis in human periodontal ligament and breast cancer cells
Authors: Jönsson D. , Wahlin Å. , Idvall I. , Johnsson I. , Bratthall G. , Nilsson B‐O.
Published: August 2005

Background:  It is important to clarify the biological function of the female sex hormones estrogen and progesterone in periodontal ligament cells, as these hormones may affect periodontal health. We have previously shown that human periodontal ligament cells express estrogen receptor β (ERβ) but not ERα, whereas human breast cancer cells (MCF7) express both ERα and ERβ. Data on progesterone receptor (PgR) expression in human periodontal ligament cells have not been reported.

Objectives:  Determine PgR expression in human periodontal ligament and MCF7 cells and to investigate how estrogen affects DNA and collagen synthesis in these two cell types showing different pattern of expression for ERα and β.

Methods:  Periodontal ligament cells were obtained from the periodontal ligament of premolars extracted for orthodontic reasons and MCF7 cells from the American Type Culture Collection (ATCC). PgR expression was determined by immunocytochemistry. DNA and collagen synthesis was determined by [3H]thymidine and l‐[3H]proline incorporation, respectively.

Results:  PgR immunoreactivity was observed in nuclei of MCF7 but not periodontal ligament cells. Treatment with estrogen (17β‐estradiol, E2) at physiological concentrations for 24 h stimulated DNA synthesis by more than two times in MCF7 cells, whereas there was no effect on periodontal ligament cell DNA synthesis. The ER blocker ICI 182780 fully reversed the stimulatory effect of E2. Not only short‐term (24 h) but also long‐term (5 days) treatment with E2 lacked effect on DNA synthesis in periodontal ligament cells. Neither periodontal ligament cell viability nor collagen synthesis was affected by E2 treatment. Identical results were observed in periodontal ligament cells from male and female subjects.

Conclusions:  Human MCF7 but not periodontal ligament cells express PgR, suggesting that progesterone via PgR affects MCF7 but not periodontal ligament cells. Further, estrogen stimulates breast cancer MCF7 cell proliferation, whereas it has no effect on proliferation of periodontal ligament cells, probably reflecting cell type specific ER expression pattern in these two cell types.
Lipopolysaccharide‐binding protein down‐regulates the expression of interleukin‐6 by human gingival fibroblast
Authors: Ren Lei , Leung Wai Keung , Loo Ting Wing , Jin Lijian
Published: August 2005

Background:  Lipopolysaccharide‐binding protein (LBP) participates in the interaction of lipopolysacchaide (LPS) with CD14 to modulate the expression of cytokines. Human gingival fibroblast may actively participate in LPS‐induced immuno‐inflammatory responses through CD14, toll‐like receptor (TLR) superfamily, MD‐2 and related adaptive proteins, leading to the expression of cytokines.

Objectives:  The present in vitro study aimed to investigate the possible effect of LBP and E. coli LPS interaction on the expression of cellular LPS receptors and IL‐6 by human gingival fibroblast.

Methods:  The mRNA expression of CD14, LBP, TLR‐2, TLR‐4, MD‐2 and IL‐6 in human gingival fibroblast explants was detected by reverse transcriptionpolymerase chain reaction (RT–PCR) in the presence or absence of E. coli LPS and recombinant human LBP (rhLBP), while IL‐6 peptides were analyzed by ELISA and immunohistochemistry, respectively.

Results:  Human gingival fibroblast could constitutively express CD14, MD‐2 and IL‐6 mRNAs, but not TLR‐2, TLR‐4 and LBP mRNAs. E. coli LPS induced the messages expression of MD‐2, TLR‐2 and −4. The expression of both IL‐6 message and peptide was up‐regulated by E. coli LPS in a dose dependent manner. Whereas rhLBP could significantly down‐regulate the expression of both mRNAs and peptides of CD14 and IL‐6 but not MD‐2 signals in the presence or absence of E. coli LPS. The up‐regulated expression of TLR‐2 and −4 by E. coli LPS no longer existed in the presence of rhLBP.

Conclusions:  This study suggests that LBP may down‐regulate the expression of IL‐6 by human gingival fibroblast. Further studies are warranted to clarify the molecular mechanisms of LBP in regulation of cytokine expression by host cells and to elaborate the relevant clinical implications.
Oral infections as predictors of mortality
Authors: Hämäläinen Piia , Meurman Jukka H. , Kauppinen Markku , Keskinen Marja
Published: August 2005

Objective:  Oral infections may increase the levels of cytokines in the blood which, in turn, are associated with early mortality in the elderly. We investigated the possible association between oral infections and mortality.

Design:  Prospective cohort study over a 5‐year follow‐up.

Setting:  Research laboratory.

Participants:  A cohort born in 1910 (n = 94) was examined in the year 1995. Five years later mortality data were obtained from the population register for 49 deceased subjects.

Main outcome measures:  Urgent need of dental treatment, lifetime, erythrocyte sedimentation rate (ESR).

Results:  The multivariate analysis adjusted for general health and lifestyle factors showed that the risk for death of subjects in urgent need of dental treatments was 3.9 times higher than that of the other subjects. Among men ESR correlated significantly with urgent need of dental treatment.

Conclusions:  Oral infections among frail elderly people may be a sign of early mortality.
A 2‐year study of Candida‐associated denture stomatitis treatment in aged care subjects
Authors: Webb Bettine C. , Thomas Cyril J. , Whittle Terry
Published: August 2005

Objective:  To test the efficacy of two methods of treatment for denture stomatitis in aged care institutions.

Background data:  Candida‐associated denture stomatitis has been associated with a lack of denture hygiene.

Materials and methods:  Sixty subjects with denture stomatitis were randomly divided into three groups: sodium hypochlorite denture soak, microwaving and control. Both methods of treatment were carried out on a nightly basis for 1 week, excepting the control group. Standardised photographs of the palate and microbial samples of palate, upper and lower dentures were taken before and after treatment.

Results:  Both hypochlorite and microwave irradiation significantly reduced the numbers of Candida and aerobic bacteria on both dentures and both methods significantly reduced Candida on the palate. However, palatal aerobic bacteria were not significantly reduced by either method and the controls showed insignificant changes at all three sites for both Candida and aerobes.

Conclusion:  While both methods of denture disinfection were successful, except for the counts of palatal aerobic bacteria, three independent observers of the clinical photographs had difficulty in identifying the controls but were more successful with the treatments. The raters also showed that there was no difference between both methods of disinfection and this agreed with the microbiological analysis.
A study to compare the oral health impact profile and satisfaction before and after having replacement complete dentures in England and Scotland
Authors: Forgie Andrew H. , Scott Brendan J. J. , Davis David M.
Published: August 2005

Objective:  To assess the oral health impact profile (OHIP) on edentulous subjects in Scotland and England who needed to have their dentures replaced, and to determine whether any change in the subjects’ assessment of their original and replacement dentures impacted on oral health related quality of life parameters.

Background:  The loss of all teeth may impact on functional activities. The OHIP is an instrument used to measure subjects’ perception of the social impact of oral disorders on their well being.

Methods:  A total of 58 edentulous subjects were studied. Subjects completed the OHIP‐14 questionnaires before and after being provided with a set of replacement complete dentures. They also assessed specific features of the upper and lower dentures. Responses were recorded on a Likert scale.

Results:  For many subjects, the responses in the before treatment questionnaires were at the lower end of the Likert scale, indicating that there were no major impacts on oral health related quality of life parameters. There were significant improvements in four of the 14 OHIP parameters assessed after treatment. With the new dentures, subjects expressed improved satisfaction, particularly for the lower prosthesis. There were no major differences between the responses of the subjects in Scotland and England.

Conclusion:  For this group of edentulous subjects, although they may need dentures to be replaced after a period of wear, this does not necessarily have significant social impacts. For this reason the provision of new dentures did not result in major changes to the OHIP.
Oral health and dental care facilities in Maltese residential homes
Authors: Schembri Alexander , Fiske Janice
Published: August 2005

Objectives:  To establish oral health care practices, including the use of dental services, in the residential homes of Malta and Gozo by assessing the knowledge of home managers and assistance of care staff regarding residents’ oral health and hygiene; and evaluating the residents’ demand for dental treatment and residential home managers response to this demand.

Subjects:  A total population sample of licensed residential homes (38) in Malta and Gozo was used comprising all home managers in government (seven), church (20), and privately run (11) residential homes.

Method:  A 19‐question questionnaire was designed, piloted and sent to the home managers requesting them to report on the dental care provision for their elderly residents. The questionnaire was distributed by post, along with a reply‐paid envelope and an explanatory letter. A response deadline of 1 month was included.

Results:  An 87% response rate was achieved. Whilst the majority of home managers (64%) were aware of domiciliary dental services, there was no code of care practice for oral health. Routine dental check‐ups were not organised for residents of most homes. Although home staffs were generally given information about residents’ oral health and hygiene, the majority did not assist residents with oral hygiene. Home managers identified the following barriers to the use of dental services by residents: cost, communication problems with dental staff, journey to place of treatment, waiting time at the dental clinic, access to premises/clinic, lack of information on oral health and dental service availability, no one to accompany the person to the clinic, and health problems such as mobility, poor eyesight, hearing impairment and mental health status.

Conclusion:  Although most home managers appreciate the importance of oral health care for their residents, the residents still face many barriers to maintaining adequate oral health care and accessing dental services.
Transient oral microflora in Greeks attending day centres for the elderly and residents in homes for the elderly
Authors: Kaklamanos E. G. , Charalampidou M. , Menexes G. , Topitsoglou V. , Kalfas S.
Published: August 2005

Objective:  To examine the isolation frequency and the carriage of yeasts, Enterobacteriaceae, Staphylococcus and Enterococcus species in oral samples from elderly Greeks living alone or in institutions.

Background:  Ageing may promote changes in the oral ecosystem, which lead to colonisation of the mouth by microbes found less commonly or only transiently in younger subjects. Previous studies indicate a geographical variation in the isolation frequency of such bacteria in elderly populations.

Materials and methods:  Medical and dental records were obtained from 66 attenders at elderly people's day centres (EPDC), and 82 residents of elderly people's homes (EPH), 66–95 years old. Mucosa smear samples were cultured on appropriate media for enumeration of the above species. Microbial identification was performed by conventional microbiological tests. The results were analysed using the Multiple Correspondence Analysis (MCA), anova and other traditional statistical tests.

Results:  No statistically significant association was found between the place of residence and the wearing of dentures. The isolation frequencies of Staphylococcus aureus, Enterococcus and Enterobacteriaceae species were 21.6, 20.3 and 7.4% respectively. MCA, and further statistical analysis, revealed that the place of residence affected the isolation frequency of years (54.9% in EPH vs. 37.9% in EPDC). Moreover, anova showed that living in EPH increased the carriage of yeasts.

Conclusions:  Elderly Greeks exhibit a moderate to high oral carriage of transient bacteria compared with other elderly populations. Living in EPH seems to increase both the isolation frequency and carriage of yeasts.
Level of education and incidence of caries in the elderly: a 5‐year follow‐up study
Authors: Siukosaari P. , Ainamo A. , Närhi T. O.
Published: August 2005

Objective:  This study aimed to examine the possible association between level of education and 5‐year caries increment in the elderly inhabitants of Helsinki.

Background:  Low salivary flow and high numbers of salivary microorganisms are associated with the presence of caries, but cannot predict the increment in caries in the elderly.

Materials and methods:  This study group was derived from a population‐based Helsinki Aging Study, which consisted of a random sample of elderly born in 1904, 1909 and 1914. The 71 dentate elderly who underwent clinical oral examinations at baseline (1990–91) and 5 years later (1995–96) were included in the study group. Decayed, Missing or Filled Tooth (DMFT) and Root Caries Index (RCI) indexes were used to study subject’ caries experience. Data on subjects’ education came from questionnaire studies. The subjects were divided into four groups according to their level of education and occupation. Bivariate and multivariate analyses were used to evaluate relationships between subjects’ caries experience and level of education.

Results:  At baseline the elderly with high level of education had more teeth and more root surfaces at risk than those with low level of education. Number of teeth decreased (−1.085, p < 0.0001), while both DMFT (1.164, p < 0.0001) and RCI (0.081, p < 0.0001) indices increased during follow‐up. The increments in DMFT and RCI were not directly associated with the level of education. Multivariate analysis in which subjects’ gender, number of teeth, level of education, frequency of eating and frequency of brushing were taken into consideration, showed no significant association with caries increment.

Conclusions:  Within the limitations of this study it can be concluded that the level of education of the elderly is not directly associated with the increment in caries.
Is Metformin Therapy for Polycystic Ovary Syndrome Safe During Pregnancy?
Authors: Brock Birgitte , Smidt Kamille , Ovesen Per , Schmitz Ole , Rungby Jørgen
Published: August 2005

Abstract: Polycystic ovary syndrome is characterized among other things by oligo‐amenorrhea and may account for more than 75% of cases with anoluvatory infertility. Due to its positive effects on polycystic ovary syndrome‐induced infertility metformin has become one of the most common drugs used in this group of patients. The efficacy of the drug as well as the first reports on metformin used in pregnancy has encouraged the continued use of the drug after conception. This MiniReview reviews the current pros and cons of metformin use in pregnancy while awaiting the results of ongoing randomised, controlled clinical trials addressing the subject.
Effects of Immunoglobulin G from Patients with Dilated Cardiomyopathy on Rat Cardiomyocytes
Authors: Christ Torsten , Adolph Esther , Schindelhauer Stefan , Wettwer Erich , Dobrev Dobromir , Wallukat Gerd , Ravens Ursula
Published: August 2005

Abstract: This study was designed to compare the effects of purified antibodies against the β1‐adrenoceptor autoantibodies and total immunoglobulin G obtained during immunoadsorption on L‐type Ca2+ currents, action potentials and cell shortening, in rat ventricular myocytes. Patients with dilated cardiomyopathy frequently develop autoantibodies against β1‐adrenoceptors, which can be removed by immunoadsorption. There is some controversy, however, whether the beneficial effects of this therapeutic option are due to the removal of cardiostimulatory or cardiodepressive antibodies. Therefore we studied the effects of immunoglobulin G on two of the regulators of excitation‐contraction coupling and on cell shortening. Immunglobulin G was obtained during immunoadsorption therapy. Dissociated myocytes from rat hearts were electrically stimulated and cell shortening was measured by cell edge detection. Single electrode patch clamp technique in current or voltage clamp mode was used to measure L‐type Ca2+ currents or action potentials, respectively. (−)‐Isoprenaline was used for comparative purposes. In comparison to (−)‐isoprenaline, immunoglobulin G increased Ca2+ current to a similar extent, but prolonged the plateau duration of action potentials to a lesser extent. Immunoglobulin G and β1‐adrenoceptor enhanced cell shortening to a similar degree, however, the effects were smaller than with (−)‐isoprenaline. The increase in contraction amplitude was prevented by (−)‐bisoprolol. We conclude that both β1‐adrenoceptors and immunoglobulin G derived from patients positive for β1‐adrenoceptor autoantibodies mediate the cardiostimulatory effects via β1‐adrenoceptors.
Subchronic Toxicity of Baltic Herring Oil and its Fractions in the Rat (III) Bone Tissue Composition and Dimension, and Ratio of n‐6/n‐3 Fatty Acids in Serum Phospholipids
Authors: Stern Natalia , Korotkova Marina , Strandvik Birgitta , Oxlund Hans , Öberg Mattias , Håkansson Helen , Lind P. Monica
Published: August 2005

Abstract: Changes in total bone mineral density determined by the bone‐ash method were recently demonstrated in rats, exposed to Herring oil from the contaminated southern part of the Baltic Sea. In the present study more detailed analysis of bone structure and biomechanics was performed and obtained results were evaluated in the context of dietary factors, such as polyunsaturated fatty acids, vitamin D and vitamin A. Baltic Sea herring oil was fractionated into one relatively pollutant‐free fraction (F1), and two fractions with pronounced enrichment of pollutants (F2 and F3). Female Sprague‐Dawley rats were fed diets supplemented with Baltic Herring oil, its fractions, Nordic Sea capelin oil or soy oil. Femur was scanned with peripheral quantitative computed tomography (pQCT) and also tested by a mechanical compression analysis. Polyunsaturated fatty acids, vitamin A and D were analysed in serum. Rats fed the high dose of herring oil exhibited shorter femur length with decreased diaphyseal cortical bone mineral density, as well as lowered metaphyseal cross‐sectional area compared to the soy oil group. Rats fed the high dose of F1 diet had increased cortical and decreased trabecular area, and higher total and trabecular bone mineral dencity. Rats fed the low dose of F2 diet showed similar changes associated with increased maximum load and energy absorption in compression test of the femoral metaphysis. In summary, our findings in changes of bone geometry and density could not be linked to any isolated exposure parameter, suggesting synergistic or antagonistic effects of several components of the test diets.
Impaired Energy Metabolism after Co‐Exposure to Leadand Ethanol
Authors: Verma Suresh Kumar , Dua Raina , Gill Kiran Dip
Published: August 2005

Abstract: The neurotoxic effects of lead are controlled by a number of nutritional, physiological and environmental factors. One such factor, ethanol, might affect the neurotoxicity of lead by regulating its absorption and distribution. However, there is little information regarding the possible biochemical mechanism by which ethanol might be affecting the state of neuronal functions in lead‐exposed individuals. Therefore, the present investigation involved the effect of alcohol (3 g/kg body weight, intragastrically, for 8 weeks) on lead‐induced (50 mg/kg body weight, intragastrically, for 8 weeks) mitochondrial dysfunction in adult rat brain. Ethanol was found to enhance the toxic effects of lead in terms of decreased cellular energy reserves (ATP levels). Co‐exposure to lead and ethanol caused marked decline in the rate of mitochondrial respiration as compared to lead alone. Further the activies of various components of the electron transport chain, viz. NADH dehydrogenase, succinate dehydrogenase and cytochrome oxidase depicted a significant decrease in the lead and ethanol co‐exposed rats as compared to the lead‐treated group. The results of the present study reflect that ethanol makes adult rat brain more vulnerable to the neurotoxic effects of lead in terms of altered mitochondrial energy metabolism.