Oilseed rape and seasonal symptoms: epidemiological and environmental studies.

BACKGROUND--There is widespread concern that the cultivation of oilseed rape leads to seasonal epidemics of respiratory symptoms in populations living in the neighbourhood, and it has been suggested that the plant is a potent allergen. A study was therefore undertaken to determine the prevalence of seasonal symptoms in rural populations close to and far from areas of oilseed rape cultivation, and to measure the levels of allergen and other potentially harmful substances released by the crop. METHODS--Random samples of 1000 adults from the general practice populations of two villages surrounded by oilseed rape fields, and 1000 adults from one village far from such cultivation, were taken. The subjects completed a previously validated questionnaire on respiratory and other symptoms, including questions on symptom seasonality, occupation, and smoking habits. Pollen and fungal spore counts were made around fields of oilseed rape and in the villages. The chemicals released by oilseed rape were measured in the field. RESULTS--Overall, 86.8% of the subjects completed the questionnaires and the populations of the two samples were generally comparable. Spring and summer exacerbations of symptoms occurred equally in the two areas in approximately 25% of the population. There were small but significant excesses of cough, wheeze, and headaches in spring in the oilseed rape area (2.3% v 1.1%, 6.8% v 4.6%, and 4.8% v 2.8%, respectively), and cough, wheeze, and itchy skin were more prevalent in smokers. Counts of oilseed rape pollen were generally low except adjacent to fields, and counts of fungal spores were mostly higher in the rape than the non-rape areas. Oilseed rape was shown to give off terpenes and these were detected close to fields. CONCLUSIONS--While it is likely that a proportion of the spring symptoms occurring in people living in close proximity to oilseed rape is caused by the plant, the excess of such symptoms is small. This, together with the low levels of pollen in the area, suggests that allergy to oilseed rape pollen is uncommon. The general prevalence of seasonal symptoms in rural areas is of interest, and a proportion of these cases is likely to be caused by factors other than allergy. Release of chemicals by plants and natural rises in summer ozone levels may be contributors.     

The role of growth hormone replacement in a growth hormone deficient patient with underlying cardiomyopathy and severe congestive heart failure.

It has been reported that growth hormone (GH) deficiency induced cardiomyopathy responds to growth hormone replacement therapy. We describe the case of a middle-aged male with cardiomyopathic heart failure and growth hormone deficiency of the adult secondary to surgical panhypopituitarism. We demonstrate clinical and hemodynamic improvement of cardiac function with growth hormone replacement therapy despite underlying structural heart disease.     

Detecting cumulative trauma disorders in workers performing repetitive tasks

On-site testing of 157 poultry processors disclosed that 50% had three or more abnormal upper extremity findings out of a total of 22 possibles. The average worker had five to six abnormal findings. Impaired pinch strength, decreased vibration sensitivity in the fingertips, and reports of current numbness were the most prevalent. Of workers with signs, 25% reported no symptoms, whereas only 8% of workers reported symptoms but had no signs. The investigators concluded that this measurement method has utility for assessments of worker populations to determine prevalence of CTDs and, potentially, for preclinical detection of these disorders to permit early intervention, reduce medical costs, and minimize disability. The need for accurate measurement to enhance early detection and prevention is discussed.     

The relationship between nasal airway cross-sectional area and nasal resistance

Mouth breathing in response to an impaired nasal airway is thought to have clinical consequences. Physiologically, mouth breathing occurs whenever the body senses that nasal resistance is inappropriately high. In physical terms mouth breathing is a response that enlarges the upper airway and, by doing so, reduces airway resistance. In the past measurements of nasal resistance have been used as an index of airway impairment. Recently, we introduced a technique that estimates cross-sectional size of the airway, a variable that directly determines the magnitude of airway resistance. The purpose of the present study was to determine the precise effects of nasal airway size on nasal airway resistance so that the relationship between the two could be described in mathematic terms. There were two phases to the study--one involving a model and simulated breathing, and the other involving 100 subjects demonstrating normal and impaired nasal airways. The pressure-flow technique for estimation of nasal airway size and nasal airway resistance was used. The following equation was generated from the data: Resistance = 1.9 + (Formula: see text). The relationship between the two variables is nonlinear--that is, size of the airway has its greatest effect on resistance when the airway is less than 0.4 cm2 and a much lesser effect at larger airway sizes. The study also showed that nasal airway resistance generally does not fall very much below 1.9 cm H2O/L/S during breathing even when the airway is very large. This probably relates to the need to maintain an adequate level of airway resistance for alveolar gas exchange.(ABSTRACT TRUNCATED AT 250 WORDS)     

Egg-sharing in assisted conception: ethical and practical considerations

The present acute shortage of eggs for donation cannot be overcomeunless adequate guidelines are set to alleviate the anxietiesregarding payments, in cash or kind, to donors. The currentHuman Fertilisation and Embryology Authority (HFEA) guidelinesdo not allow direct payment to donors but accept the provisionof lower cost or free in-vitro fertilization (IVF) treatmentto women in recognition of oocyte donation to anonymous recipients.Egg-sharing achieved in this way enables two infertile couplesto benefit from a single surgical procedure. However, the practicalguidelines related to this approach are ill-defined at the presenttime leading to some justifiable uncertainty. A pilot studywas therefore undertaken in order to establish the place ofegg-sharing in an assisted conception programme. The currentHFEA guidelines on medical screening of patients, counselling,age and rigid anonymity between the donor and recipient werefollowed. The study involved 55 women (25 donors and 30 recipients)in 73 treatment cycles involving fresh and frozen-thawed embryos.Donors were previous IVF patients who, regardless of their abilityto pay, shared their eggs equally with matched anonymous recipients.They paid only for their consultations and tests right up tothe point of being matched with a recipient The sole recipientpaid the cost applicable in egg donation of a single egg collection,although both received embryo transfers. The results indicatethat although the recipients were older than the donors (41.4± 0.9 versus 31.6 ± 0.5 years), and there wasno difference in the mean number of eggs allocated, the percentagefertilization rates, or the mean number of embryos transferred,there were more births per patient amongst recipients than amongstdonors (30 versus 20%). We conclude that providing the donorsare selected carefully, this scheme whereby a sub-fertile donorhelps a sub-fertile recipient is a very constructive way ofsolving the problem of the shortage of eggs for donation. Thereare also the advantages of including a group of women who wouldotherwise be denied treatment Problems related to ‘patientcoercion’ can, in our view, be fully overcome by the applicationof strict common-sense safeguards. The ideal of pure altruismis not without its medical and moral risk. The success of egg-sharingdepends on shared interests and a degree of altruism betweenthe donor, the recipient and the centre. The current HFEA guidelinesshould be applauded for enabling a highly effective conceptof mutual help to develop.     

A Strain Device Imposing Dynamic and Uniform Equi-Biaxial Strain to Cultured Cells

The objective of this study is to design a new apparatus to allow the control of the magnitude and frequency of dynamic stretch applied uniformly to cells cultured on a silicon elastic membrane. The apparatus is designed to produce equi-biaxial dynamic stretches with area changes ranging from 0% to 55% and frequencies ranging from 0 to 2 Hz. Homogeneous finite strain analysis using triangles of markers was performed to compute the symmetric two-dimensional Lagrangian strain tensor on the membrane. Measurements of strain in both static and dynamic conditions showed that the shear component of the strain tensor (E_rc) was near zero, and that there was no significant difference between radial (E_rr) and circumferential (E_cc) components, indicating the attainment of equi-biaxial strain. Bovine aortic endothelial cells were transiently transfected with a chimeric construct in which the luciferase reporter is driven by TPA-responsive elements (TRE). The transfected cells cultured on the membrane were stretched. The luciferase activity increased significantly only when the cells were stretched by 15% or more in area. Cells in different locations of the membrane showed similar induction of luciferase activities, confirming that strain is uniform and equi-biaxial across the membrane. © 1998 Biomedical Engineering Society. PAC98: 8780+s, 8745-k, 8722-q     

An audit of occupational medicine consultation records

There is a need to develop and test methods of audit of theconsultation process in occupational medicine and to draw conclusionsfrom the findings. An external audit was carried out on 313randomly selected consultation records from the occupationalhealth services of three health boards over a 26-month period.Additionally, nine months after the date of the first externallyaudited sample, a prospective internal audit was commenced withinone board. In 58 of the consultations selected (19 per cent),audit was not possible mainly because records could not be found.In an appreciable proportion of the rest, there were shortcomingsin the referral record or in the consultation record. The consultationrecords of ‘career’ occupational physicians werebetter than those of ‘non-career’ physicians, especiallyin recording specific diagnoses (91 per cent vs. 67 per cent;P<0.0001) and in conclusions regarding occupational implications(86 per cent vs. 74 per cent; P<0.0001). Multivariate regressionsshowed a highly significant improvement associated with prospectiveinternal audit in one item, namely the record of occupationalimplications. However, the magnitude of this difference beforeand after audit was smaller than the independent differencearising from the career status of the physicians. The valueof medical audit in improving quality of care and educationin occupational medicine is discussed.