An alternative approach to primary rhinoplasty using Walsham forceps.

BACKGROUND: The successful execution of lateral osteotomies in rhinoplasty is an important step that can influence the functional and aesthetic outcome of the procedure. OBJECTIVE: This paper describes an alternative method for achieving mobilisation of the nasal bones by careful application of Walsham forceps during primary rhinoplasty.

Exposure of birds to radionuclides and other contaminants in Special Protection Areas (SPAs) in North-West England.

There has been a decline in the population of some bird species at Morecambe Bay and the Solway Firth Special Protected Areas in North-West England during the last fifty years. It was suggested that the declines were caused, in part, by contaminants in the food and environment, primarily from the radioactive effluent discharge from the Sellafield Ltd nuclear fuel reprocessing plant in Cumbria. This study analysed bird feathers and tissues, vegetation and sediment for radionuclides, metals and persistent organic compounds. The non-radionuclide results were all low compared to relevant action limits. The ERICA model was used with field data to estimate the radiological dose to birds from exposure to (137)Cs and (241)Am with results between 1.26 to 3.83 microGy h(-1), below the ERICA screening level of 10 microGy h(-1) and within the IAEA 40 microGy h(-1) guideline value below which potential adverse impacts on biota are unlikely. The study showed no link between bird population decline and anthropogenic discharges to the SPAs.

An approach to the assessment of risk from chronic radiation to populations of European lobster, Homarus gammarus (L.).

The basic principles underlying a four-discrete age group, logistic, growth model for the European lobster Homarus gammarus are presented and discussed at proof-of-concept level. The model considers reproduction, removal by predation, natural death, fishing, radiation and migration. Non-stochastic effects of chronic low linear energy transfer (LET) radiation are modelled with emphasis on (99)Tc, using three endpoints: repairable radiation damage, impairment of reproductive ability and, at higher dose rates, mortality. An allometric approach for the calculation of LD(50/30) as a function of the mass of each life stage is used in model calibration. The model predicts that at a dose rate of 1 Gy day(-1), lobster population reproduction and survival become severely compromised, leading eventually to population extinction. At 0.01 Gy day(-1), the survival rate of an isolated population is reduced by 10%, mainly through loss of fecundity, comparable to natural migration losses. Fishing is the main ecological stress and only dose rates in the range 0.03-0.1 Gy day(-1) can achieve discernible effects above it. On the balance of radiation and other ecological stresses, a benchmark value of 0.01 Gy day(-1) is proposed for the protection of lobster populations. This value appears consistent with available information on radiation effects in wildlife.

An approach for the assessment of risk from chronic radiation to populations of phytoplankton and zooplankton.

A conceptual model of the effects of chronic radiation on a population of phytoplankton and zooplankton in an oceanic nutrient layer is presented. The model shows that there are distinct threshold dose rates at which the different plankton populations become unsustainable. These are 10,400 microGy h(-1) for phytoplankton and 125 microGy h(-1) for zooplankton. Both these values are considerably greater than the current screening values for protection of 10 microGy h(-1). The model highlights the effects of predator-prey dynamics in predicting that when the zooplankton is affected by the radiation dose, the phytoplankton population can increase. In addition, the model was altered to replicate the dose rates to the plankton of a previous ERICA Irish Sea assessment (24 microGy h(-1) for zooplankton and 430 microGy h(-1) to phytoplankton). The results showed only a 10% decrease in the zooplankton population and a 15% increase in the phytoplankton population. Therefore, at this level of dose, the model predicts that although the dose rate exceeds the guideline value, populations are not significantly affected. This result highlights the limitations of a single screening value for different groups of organisms.

Laboratory and field studies of polonium and plutonium in marine plankton.

Uptake experiments were successfully undertaken for polonium and plutonium in the marine diatom Skeletonema costatum. Experiments were complemented with a field study which yielded concentration factors for these radionuclides for plankton samples collected in the eastern Irish Sea. The uptake experiment produced uptake half times of 0.8 and 0.6 days for plutonium and polonium, respectively. Concentration factors of 3.1 x 10(5) l kg(-1) for plutonium and 2.4 x 10(5) l kg(-1) for polonium were consistent with those suggested by the IAEA for phytoplankton. Concentration factors derived from the field study were 2 x 10(3) l kg(-1) for plutonium and 1.4 x 10(4) l kg(-1) for polonium and were more consistent with IAEA values for zooplankton rather than phytoplankton. The maximum calculated dose rate due to Po and Pu in plankton sampled in the field was 0.12 microGyh(-1). In applying the laboratory-derived phytoplankton CF values for Po and Pu, higher dose rates, in the range 6-11 microGyh(-1), were calculated. The latter values are well below the UNSCEAR and IAEA review value of 400 microGyh(-1), and are also below the Environment Agency marine action level of 40 microGyh(-1).

The effect of phosphate content on the bioactivity of soda-lime-phosphosilicate glasses.

We report on the bioactivity of two series of glasses in the SiO(2)-Na(2)O-CaO-P(2)O(5) system after immersion in simulated body fluid (SBF) after 21 days. The effect of P(2)O(5) content was examined for compositions containing 0-9.25 mol.% phosphate. Both series of glasses degraded to basic pH, but the solutions tended towards to neutrality with increasing phosphate content; a result of the acidic phosphate buffering the effect of the alkali metal and alkaline earth ions on degradation. Bioactivity was assessed by the appearance of features in the X-ray diffraction (XRD) traces and Fourier transform infrared (FTIR) spectra consistent with crystalline hydroxyl-carbonate-apatite (HCAp): such as the appearance of the (002) Bragg reflection in XRD and splitting of the P-O stretching vibration around 550 cm(-1) in the FTIR respectively. All glasses formed HCAp in SBF over the time periods studied and the time for formation of this crystalline phase occurred more rapidly in both series as the phosphate contents were increased. For P(2)O(5) content >3 mol.% both series exhibited highly crystalline apatite by 16 h immersion in SBF. This indicates that in the compositions studied, phosphate content is more important for bioactivity than network connectivity (NC) of the silicate phase and compositions showing rapid apatite formation are presented, superior to 45S5 Bioglass which was tested under identical conditions for comparison.

Dynamic model for the assessment of radiological exposure to marine biota.

A generic approach has been developed to simulate dynamically the uptake and turnover of radionuclides by marine biota. The approach incorporates a three-compartment biokinetic model based on first order linear kinetics, with interchange rates between the organism and its surrounding environment. Model rate constants are deduced as a function of known parameters: biological half-lives of elimination, concentration factors and a sample point of the retention curve, allowing for the representation of multi-component release. The new methodology has been tested and validated in respect of non-dynamic assessment models developed for regulatory purposes. The approach has also been successfully tested against research dynamic models developed to represent the uptake of technetium and radioiodine by lobsters and winkles. Assessments conducted on two realistic test scenarios demonstrated the importance of simulating time-dependency for ecosystems in which environmental levels of radionuclides are not in equilibrium.

Uptake and depuration of 131I from labelled diatoms (Skeletonema costatum) to the edible periwinkle (Littorina littorea).

Uptake and depuration of (131)I into winkles through consumption of the diatom Skeletonema costatum is described. The work follows on from previous studies that investigated the uptake of iodine into winkles from seawater and seaweed. Incorporation of (131)I in S. costatum from labelled seawater followed linear first-order kinetics with an uptake half-time of 0.40 days. Iodine uptake in winkles from labelled S. costatum also followed linear first-order kinetics, with a calculated equilibrium concentration (C(infinity)) of 42Bqkg(-1) and a transfer factor (TF) of 1.1x10(-4) with respect to labelled diatom food. This TF is lower than that observed for uptake of (131)I in winkles from labelled seaweed. For the depuration stage, a biphasic sequence with biological half-lives of 1.3 and 255 days was determined. The first phase is biokinetically important, given that winkles can lose two-thirds of their activity during that period. This study shows that, whilst winkles can obtain radioactive iodine from phytoplankton consumption, they do not retain the majority of that activity for very long. Hence, compared with other exposure pathways, such as uptake from seawater and macroalgae, incorporation from phytoplankton is a relatively minor exposure route.

Augmentation of the nasal dorsum using Gore-Tex: intermediate results of a retrospective analysis of experience in 66 patients.

Out of the numerous implant materials that have been used for augmentation of the nasal dorsum, autogenous cartilage is considered to be the optimal grafting material due to its versatility and long-term survival. However, in the case of extensive augmentation often an alternative grafting material is needed. Homologous cartilage seems an attractive option, but is not commonly used because of the fear of disease transmission, the long-term unpredictability and the possibility of warping. Alloplastic grafts have offered varying degrees of success in rhinoplasty, but have resulted in significant complications as well. Lately, expanded polytetrafluorethylene (Gore-Tex(R)) has proven to be a promising synthetic material in nasal dorsal augmentation. However, convincing long-term success compared to autogenous cartilage grafts is still lacking and numbers are insufficient. This paper consists of a prelimary report about the use of Gore-Tex(R) soft-tissue patches in nasal dorsal augmentation in 66 patients over a 6-year period, which forms the largest European series so far. No complications were observed in either primary (29%) or revision rhinoplasties (71%).

Medialization of electrode array in cochlear implantation.

In the last few years, the main thrust of research into cochlear implantation has centred around the development of advanced multi-channel implants. A new area of development is now concentrating on maximizing the potential of each individual electrode in order to improve the quality of hearing. This study involved the medialization of the cochlear implant electrode array using a silastic positioner in five patients. Two parameters were measured, namely current units needed to produce a stapedial reflex, and impedance levels between the electrode and modiolus. On insertion of the cochlear implant, readings were taken before the insertion of the positioner, immediately afterwards and at two months.

Revision rhinoplasty: review of deformities, aetiology and treatment strategies.

Rhinoplasty has always been one of the most challenging aspects of facial surgery as it requires a precise assessment of the deformity, a strong grasp of nasal support mechanisms plus soft tissue skin envelope and a realistic appraisal of the outcome expected acutely and over a long period of time. This fine balance is often achieved by retrospective analysis of post-rhinoplasty results in order to highlight repeated problems and improve upon them. This study reviews 110 patients in which a total of 407 deformities were found. These are divided into upper, middle and lower thirds with a subdivision of individual deformities within each group. There is also a comparison of the results obtained from similar studies over a period of four decades to those in our study, which reveals that the post-rhinoplasty deformities noted in these studies occur with a similar frequency to those in our paper.

A charged-particle microbeam: II. A single-particle micro-collimation and detection system.

The use of a charged-particle microbeam provides a unique opportunity to control precisely, the number of particles traversing individual cells and the localization of dose within the cell. The accuracy of 'aiming' and of delivering a precise number of particles crucially depends on the design and implementation of the collimation and detection system. This report describes the methods available for collimating and detecting energetic particles in the context of a radiobiological microbeam. The arrangement developed at the Gray Laboratory uses either a 'V'-groove or a thick-walled glass capillary to achieve 2-5 microns spatial resolution. The particle detection system uses an 18 microns thick transmission scintillator and photomultiplier tube to detect particles with > 99% efficiency.

Facial paralysis caused by a lymphoepithelial cyst located in the parotid gland.

We report the case of an acute onset facial paralysis which was caused by a benign lymphoepithelial cyst found in the parotid, an association which is a rarity in the literature. The diagnosis and surgical management is discussed. This report emphasises the clinical principle that parotid masses causing an acute facial palsy are not necessarily malignant in nature. Intra-operative frozen section histology is helpful in saving the patient from unnecessarily radical surgery.

The elimination of dracunculiasis in Igbon, Oyo State, Nigeria: the success of self-help activities.

Guinea worm disease, dracunculiasis, is widespread in rural Nigeria, where an estimated 2.5 million cases occur every year. This study documents the use of multiple intervention strategies, based on community self-help in collaboration with health researchers, to eliminate Guinea worm in the village of Igbon, in Oyo State, Nigeria. In November 1978 the village had a point prevalence rate of 59% at the height of the period of patency and disease transmission. Advised by the university-based researchers who conducted the survey, villagers combined in a series of cooperative efforts which culminated in the construction of wells which provided them with a protected water supply. Since 1982 no cases of Guinea worm have been recorded in the village. Igbon is now free from its annual 'festival of agony', the village has increased in population, and economic activities flourish. Self-help activities such as those carried out in Igbon could be a very useful part of the current Guinea worm eradication campaign in Nigeria.

Guinea worm: an in-depth study of what happens to mothers, families and communities.

This paper reports on the impact of maternal morbidity due to guinea worm, dracunculiasis, on the care and health of children under 24 months old, and the way in which the mothers and the family coped with the often extended periods of disability. This qualitative study is based on observation and in-depth interviewing, supplemented by focus group discussions. Of 42 mothers with guinea worm in two hyperendemic areas of Oyo and Kwara States, 28 were either bedridden or only able to hobble short distances with the help of a stick; the average period of incapacity was almost 9 weeks. Of the four maternal roles identified (child care, self care, domestic tasks, income generation), the women gave priority to child care; 34 of the 42 mothers needed help in child care. Coping networks operated principally within the extended family, but also included women in other households, and women from beyond the community. Thus the impact of a mother's illness extended beyond her children and family to the wider community. This qualitative study thus reveals the multifaceted impact of a disease on individuals and on the community. The study stresses the need for, and availability of, effective methods for controlling guinea worm by utilizing community cooperation to provide protected water sources and other preventive measures against the disease.

Child health and child care in Okelele: an indigenous area of the city of Ilorin, Nigeria.

This paper provides a detailed analysis of the survival rates and health problems of a cohort of children born during a 5-yr period in part of the city of Ilorin, Nigera. The findings are linked to a demographic and environmental study which indicates that the study area was relatively stable in terms of family structure and population turnover. Most people work in the informal sector, in trading, small scale crafts and service industries. At the time the survey began, in 1979, the provision of piped water supplies to the area was unreliable and sanitation provisions rudimentary. Most of the people had little or no formal education and were very poor. The study indicated that health status had improved over the 5-yr period, compared to a baseline study conducted in 1979. Common causes of child mortality and morbidity included diarrhea, acute respiratory infections, measles, and malaria. The infant mortality rate was 41.5/1000. The availability of clinic care at nominal cost, and the attendance of mothers at the clinic for checkups and immunization, resulted in a higher level of health for their children than otherwise would have been possible. Some problems of primary health care in the area are mentioned, in the light of Nigeria's current budgetary problems, and the utilization of existing strong social support networks to improve health care and environmental sanitation and water supply is suggested.

The impact of a UNICEF-assisted rural water project on the prevalence of guinea worm disease in Asa, Kwara State, Nigeria.

This paper demonstrates that protected water supplies, in the form of boreholes, can reduce the prevalence of dracunculiasis (guinea worm disease) in affected communities from a point prevalence of greater than or equal to 50% to 0% or near 0% within 3 years of intervention. Studies in Nigeria show that boreholes sited within a village and used exclusively for drinking water are most effective, while less accessible or malfunctioning boreholes have a less dramatic impact on prevalence. In contrast to the situation in villages served with boreholes, the prevalence of guinea worm in the unserved villages remained almost unchanged. The rapid benefits of protected rural water supplies and the decline of dracunculiasis, including the rise in school enrollment and fall in the rate of school absenteeism, are highlighted together with other socioeconomic benefits.