Field-scale dispersal of Aphodius dung beetles (Coleoptera: Scarabaeidae) in response to avermectin treatments on pastured cattle.

Very few studies have examined, at the field scale, the potential for faecal residues in the dung of avermectin-treated cattle to affect dung-breeding insects. The current study examined populations of dung beetles (Scarabaeidae: Aphodius) using pitfall traps baited with dung from untreated cattle on 26 fields across eight farms in southwest Scotland. The fields were grazed either by untreated cattle or by cattle treated with an avermectin product, i.e. doramectin or ivermectin. During the two-year study, significantly more beetles were trapped in fields grazed by treated cattle (n=9377 beetles) than in fields where cattle remained untreated (n=2483 beetles). Additional trials showed that beetles preferentially colonised dung of untreated versus doramectin-treated cattle. This may explain the higher captures of beetles in traps baited with dung of untreated cattle, which were located in fields of treated cattle. Given that Aphodius beetles avoided dung of treated cattle in the current study, the potential harmful effects of avermectin residues in cattle dung could be reduced through livestock management practices that maximise the availability of dung from untreated livestock in areas where avermectins are being used.

Congenital cholesteatoma of occipital bone or intradiploic epidermoid cyst? One and the same disease.

OBJECTIVE: We report an extremely rare case of congenital cholesteatoma affecting the occipital bone. METHODS: We present a case report, plus a review of the world literature on similar lesions. RESULTS: This case report describes the presentation and treatment of a congenital cholesteatoma arising in an apparently unique location within the occipital bone, with no effect on middle-ear structure or function. The different imaging characteristics of this lesion are described and illustrated. The discussion centres on the differentiation of this lesion from intradiploic epidermoid cysts, more commonly described in the neurosurgical literature. The possible methods of pathogenesis are discussed, along with treatment suggestions. CONCLUSION: Congenital cholesteatomas and intradiploic epidermoid cysts are indistinguishable both histologically and radiologically, and would appear to be the same disease.

Effects of avermectin residues in cattle dung on yellow dung fly Scathophaga stercoraria (Diptera: Scathophagidae) populations in grazed pastures.

The effects of avermectin exposure on natural populations of the yellow dung fly, Scathophaga stercoraria Linnaeus, were investigated at the field scale on farms in south-west Scotland. Pastures forming the focus of the study were grazed with either untreated cattle or cattle receiving standard, manufacturer-recommended treatment regimes of an avermectin product. Flies were sampled between April and July in 2002 and 2003 using dung-baited pitfall traps. Abundance and wing asymmetry in S. stercoraria populations were examined in relation to a range of environmental and management variables (including avermectin exposure, pasture management intensity, weather and season). Data used for abundance analyses were collected in fields where treated cattle had been dosed with either doramectin or ivermectin, while the data for the asymmetry analyses were from a subset of fields where treated cattle had been dosed with doramectin only. While abundance of S. stercoraria varied significantly between years and with season, there was no difference in their abundance between fields grazed by avermectin-treated or untreated cattle. Asymmetry was significantly higher in fly populations in fields grazed by doramectin-treated cattle, suggesting that exposure to doramectin during development could have imposed some degree of environmental stress. While these results suggest that exposure to doramectin residues in dung on grazed pastures may have sublethal effects on the insects developing in that dung, there was no evident avermectin effect on the abundance of adult S. stercoraria occurring in the pastures.

The interaction between general practitioners and occupational health professionals in relation to rehabilitation for work: a Delphi study.

BACKGROUND: Anecdotally, communication between general practitioners (GPs) and occupational health professionals is poor and acts as a barrier to successful rehabilitation for work. It is not known how widely this view is held by the many stakeholders in rehabilitation for work, or how important the observation is in its effect. METHODS: A Delphi study was conducted by initial semi-structured telephone interview, followed by a three-round collation and feedback of opinion by e-mail. The 25 participants were identified by suggestion within the study process for their position as key informants within a wide range of stakeholders. RESULTS: The process generated a consensus statement which identifies the extremely important nature of rehabilitation for work, the crucial role by GPs, the central role of occupational health professionals in case management and the barrier represented by the often very poor communication between them. CONCLUSION: The way forward is to improve communication by mutual education and understanding and a team approach to rehabilitation strategy. This may be facilitated by the GPs who work in occupational health and disability assessment and the involvement of other health professionals to great benefit for all stakeholders.

Severe hyponatraemia: investigation and management in a district general hospital.

AIMS: To study the incidence, investigation, and management of severe hyponatraemia (serum sodium < 120 mmol/litre) over a period of six months in a district general hospital. METHODS: The laboratory computer was used to identify all inpatients who had a serum sodium concentration of less than 120 mmol/litre over a six month period. The records of these patients were reviewed for the relevant demographic, clinical, and laboratory data, in addition to diagnosis, treatment, and outcome of hospitalisation. RESULTS: Forty two patients were studied, with a female to male ratio of 2 : 1. Nine patients had central nervous system symptoms, and four of these patients died in hospital. Only 14 patients had their urinary electrolytes and/or osmolality checked. A diagnosis of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) was mentioned in eight patients, sometimes without checking their urinary electrolytes or osmolality. Twenty one patients died in hospital. The patients who died did not have lower serum sodium values or a higher rate of correction of hyponatraemia, but they all suffered from advanced medical conditions. CONCLUSIONS: The possible cause of hyponatraemia should always be sought and that will require an accurate drug history, clinical examination, and assessment of fluid volume, plus the measurement of urinary electrolytes and osmolality in a spot urine sample. The diagnosis of SIADH should not be confirmed without the essential criteria being satisfied. The current or recent use of diuretics is a possible pitfall in the diagnosis of SIADH. The rate of serum sodium correction of less than 10 mmol/day is probably the safest option in most cases.

No effect of low-dose aspirin for the prevention of heterotopic bone formation after total hip replacement: a randomized trial of 2,649 patients.

2,649 patients scheduled for elective total hip replacement were recruited to the Heterotopic Bone Formation Sub-study of the Pulmonary Embolism Prevention Trial. Heterotopic bone formation was determined by radiographic examination and associated late postoperative outcomes were assessed by telephone interview. Heterotopic bone formation was observed in 627 (31%) of 2,048 radiographic examinations. There was no detectable effect of low-dose aspirin on the risks of heterotopic bone formation (RR 0.98; 95% CI 0.85-1.12), late postoperative pain (RR 1.10; 95%CI 0.91-1.35) or late postoperative impaired function (RR 1.03; 95% CI 0.94-1.12). The balance of benefits and risks of low-dose aspirin is determined by its effects on vascular events and bleeding, since it has no major effects on heterotopic bone formation or associated clinical outcomes.

The presentation, treatment and outcome of renal cell carcinoma in old age.

OBJECTIVE: To review clinical presentation and outcome of patients with a diagnosis of renal cell carcinoma at a district general hospital and assess whether older patients were more likely to present in a non-specific manner or receive more conservative management and whether their survival was less favourable. SUBJECTS AND METHODS: 39 patients presenting with a diagnosis of renal cell carcinoma between 1987 and 1995 were identified from hospital activity analysis data and histopathology records. We divided the subjects into young patients (< 69 years: n = 27) and elderly patients (>70 years: n = 10), and made a retrospective analysis of clinical features, laboratory results, pathology, staging, treatment and survival from hospital records. RESULTS: Anaemia, hypertension and weight loss were common clinical features in both young and elderly groups. The prevalence of non-urological symptoms did not differ between study groups. Anaemia was frequently microcytic and hypochromic. Hypertension was present in 46% of patients and one-third of these were newly diagnosed. In 19% of patients with renal cell carcinoma, the diagnosis was made incidentally while imaging for other indications. Elderly patients were as likely to receive surgical treatment as younger patients. Survival differed with stage but not age. CONCLUSIONS: Neither clinical presentation, management nor survival differed between the young and elderly subjects. Renal cell carcinoma should be considered in elderly patients with systemic features such as malaise or weight loss associated with anaemia, hypertension and raised erythrocyte sedimentation rate.

Increase of HIV-1 subtype A in Central African Republic.

The concomitant presence of five distinct HIV-1 subtypes and of unclassified HIV-1 was reported in Bangui, Central African Republic (C.A.R.) between 1990 and 1991. This previous study was conducted in individuals belonging to the C.A.R. Armed Forces (FACA) Cohort and in patients from the University Hospital of Baugui. To follow the HIV-1 subtype distribution in Bangui over time, we conducted a cross-sectional surveillance of HIV-1 subtypes between 1987 and 1997 in three groups of individuals in Bangui: 47 men belonging to the FACA Cohort, 38 patients from the CNHUB hospital, and 51 individuals consulting the sexually transmitted diseases (STD) clinic. One hundred and ten HIV-1 were subtyped by heteroduplex mobility assay (HMA) and/or sequencing of env regions encompassing the V3 domain. By comparing the HIV-1 distribution in two time periods (1987-1991 and 1991-1996) in the FACA cohort, we observed a significant increase of subtype A from 43.7% to 83.9%. This subtype distribution does not seem specific to the FACA cohort, in that subtype A accounted for 46.7% of the HIV-1 infections in CNHUB patients in the first time period studied and for 69.6% in the second time period. In STD patients, subtype A infections were predominant in 1995 (72.7%) and 1997 (89.7%). Subtype E viruses could be identified in the second time period, but represented only between 6.5% and 21.8% of the infections in the three groups of individuals studied. Other subtypes (B, C, H) and non-classified HIV-1 in C2-V3 were detected with only a 3.2% to 9.1% frequency for each in the second time period. Phylogenetic analysis excluded infection by a single source for the individuals included in the study. Our data demonstrate an increase in the proportion of HIV-1 subtype A infections in Bangui that raises the question of a preferential transmissibility of specific HIV-1 variants.

Screening of vibration-induced disorders in the building industry using digital tactilometry. Results of a field study.

As occupational physicians in the building industry, we observed among these workers a high frequency of vibration exposure, during different tasks. We intended to study vibration exposure effects on vibration perception thresholds measured by digital tactilometry in this population of construction workers. A cross-sectional field study was made, 405 subjects were examined; each of them answered a questionnaire, underwent a medical examination and performed a test measuring his vibration perception thresholds, 150 subjects constituted the reference group. A close relationship between age and thresholds among the non-exposed group was observed. A threshold normalization of age of study the 204 exposed subjects was applied. Two exposure indices allowing time dependency vibration exposure analysis were defined the present daily exposure and cumulated exposure. In the examined population, thresholds rise with the present daily exposure in hours per day for 125 Hertz, while no significant influence of cumulated exposure is apparent. It was also pointed out that subjects exposed more than one and a half hour per day have higher thresholds than reference subjects, even if they do not have any clinical neurological complaints. This results seems to indicate the infraclinical feature of the test. These results suggest that screening of hand-arm vibration exposed population should be developed using this method. As occupational physicians in the construction industry, practising in Paris and surrounding areas, the authors studied the relationship between neurological disorders measured by vibrotactile perception thresholds, and hand-arm vibration exposure, among workers. They present the results of a field study they led within their institute, in collaboration with the tested workers' firms, and with the financial participation of the French Ministry of Labour.

Vigabatrin in childhood epilepsy.

Sixty-six children with various types of severe drug-resistant epilepsy were entered into a long-term, dose-rising study of vigabatrin after a 4-week run-in placebo period. All the children were receiving one to three other antiepileptic drugs, the doses of which were not changed during the 6-month dose titration phase. Following the introduction of vigabatrin, 11 patients became seizure free, and 28 responded with a greater than 50% reduction in seizure frequency. The following types of epilepsy responded favorably in order of decreasing efficacy: cryptogenic and symptomatic partial epilepsy, other symptomatic generalized epilepsy, and Lennox-Gastaut syndrome. However, three of nine patients with myoclonic epilepsy showed an increase in seizure frequency. Optimal responses were found with vigabatrin doses of 40 to 80 mg/kg/day, although no significant adverse effects were noted with doses of higher than 100 mg/kg/day. Thirty-eight responders continued on vigabatrin, 19 of whom have been treated for more than 1 year, with generally good efficacy. As a result of discontinuing concomitant antiepileptics, six patients are on monotherapy with vigabatrin, four of whom are seizure free. Vigabatrin tolerability was good, with 39 of 66 children reporting no adverse effects. Hyperkinesia was reported in 17 patients (26%), and two had to drop out of the study. All these patients had a history of hyperkinesia or mental retardation. In patients in whom vigabatrin dose was reduced because of hyperkinesia, a dose increase could later be instituted without recurrence of symptoms. There was no change in neurologic examination and no drug-related abnormalities in clinical laboratory data.(ABSTRACT TRUNCATED AT 250 WORDS)

Dose-response study of vigabatrin in children with refractory epilepsy.

Twenty children aged 2 months to 18 years were included in a dose-response study of vigabatrin as add-on therapy to preexisting antiepileptic drugs (up to two per patient). All children had severe refractory epilepsy: partial seizures with or without secondary generalization in 19, and myoclonic seizures in one. After a 2-month observation period and a 1-month add-on placebo period, a fixed dose of add-on vigabatrin was given for 2 months: 1, 1.5, or 2 g/day, according to body weight (mean dose, 60 mg/kg/day). Three patients (15%) became seizure free, and nine (45%) showed a 50% to 99% reduction in seizure frequency. In the 17 patients whose seizures were not totally suppressed, vigabatrin dose was increased for a further 2 months, and in 7 patients who still showed less than 50% reduction in seizure frequency, vigabatrin dose was increased again. Efficacy appeared unchanged by these higher doses. During a 9-month follow-up phase, no tolerance to the effects of vigabatrin was observed, with three children seizure free and 13 (65%) reporting a 50% to 99% reduction in seizure frequency. During the study, adverse effects were recorded in three children (15%), namely drowsiness, constipation, fatigue, and apathy. These effects were generally transient, being observed during the dose-modification phase and disappearing either spontaneously or on reduction of vigabatrin dose. Clinical and laboratory tolerability to vigabatrin appeared to be very good, with no patients having withdrawn from the study because of side effects. A slight reduction in red blood cell count and hemoglobin levels was noted but was of doubtful clinical significance.(ABSTRACT TRUNCATED AT 250 WORDS)

Therapeutic trial of vigabatrin in refractory infantile spasms.

Infantile spasms usually start during the first year of life and constitute one of the most difficult types of epilepsy to treat. They carry a very poor prognosis for both epilepsy and mental development. Seventy children, including 47 infants, with intractable infantile spasms were entered into an open study with vigabatrin as add-on therapy to the usual anticonvulsant treatment. All were resistant to previous treatments, including corticosteroids (43 patients), carbamazepine, benzodiazepines, and sodium valproate. Two children withdrew from the study because of intolerance to vigabatrin (hypotonia or hypertonia) before evaluation of efficacy could be made. Of the remaining 68 children, 29 (43%) showed complete suppression of spasms. Forty-six children had a greater than 50% reduction in spasms. The best response was observed in those with tuberous sclerosis (12/14 compared with 12/18 with symptomatic infantile spasms of other origin and 22/36 with cryptogenic infantile spasms). Following the initial response to treatment of these patients (n = 68), a long-term response was confirmed in 75% of children with symptomatic infantile spasms and 36% of children with cryptogenic infantile spasms. In eight children, all other anticonvulsant medication could be definitively withdrawn. Tolerability appeared excellent, with 52 of 70 patients reporting no side effects. Somnolence, hypotonia, weight gain, excitation, and insomnia were the most common problems at the beginning of the study and were usually transient. Given the poor prognosis of this type of childhood epilepsy, vigabatrin appears to be a very interesting advance in the management of drug-resistant infantile spasms.

Pharmacokinetics of the individual enantiomers of vigabatrin (gamma-vinyl GABA) in epileptic children.

1. The pharmacokinetics of the enantiomers of vigabatrin were investigated after oral administration of a single 50 mg kg-1 dose of the racemate to two groups of six epileptic children (I: 5 months-2 years, II: 4-14 years). 2. The mean (+/- s.d.) values of maximum plasma concentration and area under the plasma concentration-time curve of the R(-) enantiomer were significantly higher than those of S(+) vigabatrin in both groups: R(-) Cmax: 21 +/- 6.6 (I)-41.3 +/- 13.9 (II) vs S(+) Cmax: 13.9 +/- 4.5 (I)-23.8 +/- 12.2 (II) mg l-1; R(-) AUC: 106 +/- 28.5 (I)-147 +/- 34 (II) vs S(+) AUC: 90.9 +/- 27.9 (I)-117 +/- 26 (II) mg l-1 h. In group I, the half-life of the R(-) isomer was significantly shorter than that of the S(+) isomer; in group II, the half-lives were comparable. 3. For the R(-) enantiomer the area under the curve, and the elimination half-life increased linearly with age. 4. During chronic administration (50 mg kg-1 vigabatrin racemate twice a day for 4 days), the morning trough plasma drug concentrations did not increase.

Sheep platelets as a model for human platelets: evidence for specific PAF (platelet activating factor) receptors.

In a number of animals, the platelet response to Platelet Activating Factor (PAF) has been shown to differ considerably from that in humans. However, aggregation, release and particularly shape change were quite similar for human and sheep platelets. In this study, aggregation and shape change analysis were used to measure the response of sheep platelets to various synthetic analogs of PAF. Response is greatly reduced with no alkyl group in position 2 of PAF and decreases progressively as the number of carbons of the alkyl gets larger than three. A reduction of activity is also seen as the ether linkage at position 1 of PAF is replaced by an ester linkage. These changes are indicative of a specific membrane receptor for PAF in sheep platelets and confirm the usefulness of sheep platelets as a model for PAF-platelet interaction in humans.

Vigabatrin in the treatment of childhood epilepsies: a single-blind placebo-controlled study.

Sixty-one pediatric patients (12-229 months of age) with refractory epilepsy were treated with vigabatrin [gamma-vinyl GABA (GVG)] in a 16-week, single-blind, add-on, placebo-controlled trial. Twenty-three patients (38%) showed a reduction of more than 50% in seizure frequency; 12 patients (20%) experienced a seizure increase; and the remaining 26 did not show significant differences between placebo and GVG treatment. Among the 216 patients who entered the long-term phase after having experienced more than 50% decrease in seizure frequency, 14 continued with the same degree of improvement after 2-11 months of follow-up (mean 7.7). GVG was particularly efficient in cryptogenic partial epilepsy. Conversely, nonprogressive myoclonic epilepsy tended to be aggravated. Agitation was the most commonly observed side effect, mainly at onset of therapy in mentally retarded patients, but was easily reversed by dose reduction. GVG is a promising drug in the treatment of refractory epilepsies of childhood.