Exhaled breath condensate hydrogen peroxide and pH for the assessment of lower airway inflammation in the horse

Measurement of hydrogen peroxide (H(2)O(2)) concentration and pH in exhaled breath condensate (EBC) is useful for detection and monitoring of asthma in humans. In contrast, limited information on the use of these parameters for the investigation of lower airway inflammation (LAI) is available for horses. Aims of the current study were to investigate the intra- and inter-day variations of EBC H(2)O(2) concentration and pH in horses and establish any relationship(s) with LAI. Both intra- and inter-day variability of EBC H(2)O(2) concentration were large, while those of pH were small. No significant difference in the intra-day or inter-day H(2)O(2) concentrations or pH measurements were found in control or LAI horses, except for inter-day H(2)O(2) concentration in horses with LAI (p=0.019). There was no significant difference in EBC pH or H(2)O(2) concentration between control and LAI horses, however a trend for a reduced pH in horses with LAI was observed.

Assessment of subclinical venous catheter-related diseases in horses and associated risk factors

A total of 102 horses that had a catheter introduced intravenously to facilitate treatment had the catheterised jugular vein and contralateral vein examined by ultrasound every 48 hours. Subclinical complications were defined by thrombus formation or thickening of the venous wall, and the data were analysed to establish risk factors for the development of these complications. The horses with a rectal temperature above 38.5 degrees C when the catheter was introduced were four times more likely to develop complications, than the horses with a lower temperature. The administration of a NSAID while the catheter was in place reduced the risk of complications developing.

Assessing techniques for disinfecting sites for inserting intravenous catheters into the jugular veins of horses

The sites of insertion of catheters into the jugular veins of six horses were investigated to determine common isolates and to assess the effectiveness of two disinfection protocols with the hair coat left long, clipped or shaved. Skin commensals (Staphylococcus, Streptococcus and Micrococcus species) and environmental contaminants (Bacillus, Enterobacteriaceae, Aspergillus and Mucor species) were the microorganisms most frequently isolated. Chlorhexidine gluconate and povidone-iodine-based skin disinfection protocols resulted in significant reductions in the number of bacterial isolates from clipped sites. With chlorhexidine, there were no significant differences between the reductions observed at sites with the hair coat left long, clipped or shaved.

Consequence of Abeta immunization on the vasculature of human Alzheimer's disease brain

A major feature of Alzheimer's disease is the accumulation of amyloid-beta peptide (Abeta) in the brain both in the form of plaques in the cerebral cortex and in blood vessel as cerebral amyloid angiopathy (CAA). Experimental models and human clinical trials have shown that accumulation of Abeta plaques can be reversed by immunotherapy. In this study, we hypothesized that Abeta in plaques is solubilized by antibodies generated by immunization and drains via the perivascular pathway, detectable as an increase in cerebrovascular Abeta. We have performed a follow up study of Alzheimer's disease patients immunized against Abeta42. Neuropathological examination was performed on nine patients who died between four months and five years after their first immunization. Immunostaining for Abeta40 and Abeta42 was quantified and compared with that in unimmunized Alzheimer's disease controls (n = 11). Overall, compared with these controls, the group of immunized patients had approximately 14 times as many blood vessels containing Abeta42 in the cerebral cortex (P<0.001) and seven times more in the leptomeninges (P = 0.013); among the affected blood vessels in the immunized cases, most of them had full thickness and full circumference involvement of the vessel wall in the cortex (P = 0.001), and in the leptomeninges (P = 0.015). There was also a significantly higher level of cerebrovascular Abeta40 in the immunized cases than in the unimmunized cases (cortex: P = 0.009 and leptomeninges: P = 0.002). In addition, the immunized patients showed a higher density of cortical microhaemorrhages and microvascular lesions than the unimmunized controls, though none had major CAA-related intracerebral haemorrhages. The changes in cerebral vascular Abeta load did not appear to substantially influence the structural proteins of the blood vessels. Unlike most of the immunized patients, two of the longest survivors, four to five years after first immunization, had virtually complete absence of both plaques and CAA, raising the possibility that, given time, Abeta is eventually cleared from the cerebral vasculature. The findings are consistent with the hypothesis that Abeta immunization results in solubilization of plaque Abeta42 which, at least in part, exits the brain via the perivascular pathway, causing a transient increase in the severity of CAA. The extent to which these vascular alterations following Abeta immunization in Alzheimer's disease are reflected in changes in cognitive function remains to be determined.

Equine parascarosis under the tropical weather conditions of Ethiopia: a coprological and postmortem study

A cross-sectional coprological survey in the regions of Ada, Akaki, Bereh and Boset, and a retrospective postmortem investigation were conducted to study the epidemiology of Parascaris equorum in donkeys and horses in Ethiopia. Faecal samples from 803 working donkeys and 402 horses were collected, and the numbers of worms recovered from 112 donkeys examined postmortem between 1995 and 2004 were analysed. There was a high prevalence of infection and faecal egg output of P equorum in both donkeys and horses, and the severity of the infection in donkeys was increased irrespective of their age. The prevalence of the infection in the donkeys was 51.1 per cent and in the horses 16.2 per cent, and the prevalence in the donkeys examined postmortem was 55 per cent. There was no significant difference between different age groups of donkeys in either the prevalence or the intensity of the infection. The prevalence of the infection was significantly higher in the Ada and Akaki regions than in the Bereh and Boset regions.

Comparative study of doramectin and fipronil in the treatment of equine chorioptic mange

In equids, chorioptic mange is a common dermatitis for which there are no licensed medications in the uk. Doramectin and fipronil are licensed for the control of ectoparasites in other species and were evaluated for the treatment of 17 cases of chorioptic mange in 13 equids. Equids were included if clinical findings were indicative of chorioptic mange, chorioptes mites were positively identified and concurrent disease that could affect response to disease was not evident. A random number table was used to allocate subjects to receive doramectin (group D, eight animals) or fipronil (group F, nine animals). Each of the horses in group D were given 0.3 mg/kg doramectin (Dectomax; Pfizer) on two occasions 14 days apart by subcutaneous injection. All limbs of the horses in group F were sprayed with fipronil 0.25 per cent solution (Frontline; Merial) to the level of the stifles and elbows. Both groups were examined on the day of treatment and 14 and 28 days later to assess the behavioural signs of pruritus and the severity of the dermatological lesions. Acetate tape impressions were collected from the distal limbs and the degree of mite infestation was assessed. By day 28 there were no behavioural signs of chorioptic mange in any of the animals, and there were significant reductions in the numbers of mites in both groups. However, there were no significant reductions in the mean lesion score in either group. There was no significant difference between the effectiveness of the two treatments.

Caveolin-1 and -2 and their relationship to cerebral amyloid angiopathy in Alzheimer's disease

Cerebral amyloid angiopathy (CAA) affects over 90% of patients with Alzheimer's disease (AD) and increases the risk of cerebral haemorrhage and infarction. Caveolae--cholesterol-enriched plasmalemmal microinvaginations--are implicated in the production of amyloid beta peptide (Abeta). Caveolin-1 (CAV-1) is essential for the formation of caveolae. Caveolin-2 (CAV-2) is expressed at the plasma membrane only when in a stable hetero-oligomeric complex with CAV-1. CAV-1 and CAV-2 are highly co-expressed by endothelium and smooth muscle. Recent studies suggest that down-regulation of CAV-1 causes a reduction in alpha-secretase activity and consequent accumulation of Abeta. We have used quantitative immunohistochemical techniques to assess the relationship between CAV-1 and CAV-2 with respect to Abeta accumulation in the cerebral vasculature in a series of post mortem brains. CAV-1 and CAV-2 were co-expressed within the tunica media and endothelium of cerebral blood vessels. There were regional differences in CAV-1 immunolabelling, which was significantly greater in the frontal cortex and white matter than in the parietal lobe (in both control and AD cases) or the temporal lobe (in AD alone). However, CAV-1 labelling in AD did not differ from that in controls in any of the three lobes examined. Assessment of CAV-1 labelling in relation to the severity of CAA showed CAV-1 to be significantly increased in the frontal white matter in a subgroup of AD cases with absent/mild CAA compared with controls with absent/mild CAA and to AD cases with moderate/severe CAA, but the latter groups did not show significant differences from one another. CAV-1 labelling did not vary with age, gender, APOE genotype, post mortem delay or brain weight. Only segments of blood vessels with particularly abundant Abeta and extensive loss of smooth muscle actin showed loss of CAV-1 and CAV-2 from the tunica media. Within these vessels endothelial CAV-1 was preserved and discontinuous CAV-2 labelling was noted along the outer aspect of the vessel wall. Our findings suggest that alterations in the expression of vascular CAV-1 and CAV-2 are unlikely to play a role in the development of CAA in AD.

Cholinesterase inhibitors reduce cortical Abeta in dementia with Lewy bodies

Cholinesterase inhibitors (ChEIs) are effective symptomatic treatments in dementia with Lewy bodies (DLB), although effects on pathologic mechanisms are unknown. In the first human autopsy study examining the impact of ChEI treatment on brain pathology, we compared treated patients with DLB with matched untreated patients for cortical beta-amyloid (Abeta) and tau pathologies. Treated patients with DLB had significantly less parenchymal Abeta deposition, which is relevant to disease management and treatment of dementia patients using ChEI.

Assessment of serum protein electrophoresis for monitoring therapy of naturally acquired equine cyathostomin infections

Serum protein electrophoresis (SPE) has previously been suggested as a means of assessing cyathostomin burdens in horses, although SPE used for that purpose is supported by little evidence. This clinical research report describes a study that objectively evaluated the use of SPE on a population of 38 horses following the administration of different anthelmintics. The population was subdivided into three groups, Groups F, M and P: 7.5 mg/kg bwt fenbendazole was administered to Group F on day -12; on day 0 0.4 mg/kg bwt moxidectin was administered to Group M and 19 mg/kg bwt pyrantel was administered to Group P. Faecal worm egg counts were obtained on days -14, 0 and 10. Groups M and P acted as controls for the Group F faecal egg count reduction test (FECRT) in which a high level of benzimidazole resistance was demonstrated. Group F was then used as a control group for the FECRT for both Groups P and M. A high anthelmintic efficacy of moxidectin and pyrantel was detected. SPE was performed on venous blood collected on days 0, 10, 30, 56 and 80. As the cyathostomins infecting the horses had been shown to be highly resistant to fenbendazole, Group F then served as a control group for comparison of any changes in protein fractions. Serum proteins did not vary significantly between groups on any of the sampling dates. No significant changes in serum proteins were observed in any group and no patterns were apparent on qualitative assessment of SPE profiles. SPE was therefore concluded to be an insensitive tool for the monitoring of cyathostomin treatment in horses in a clinical environment.

Prevalence, heritability and significance of musculoskeletal conformational traits in Thoroughbred yearlings

REASONS FOR PERFORMING STUDY

The assessment of belief that equine conformation is associated with performance and durability is a fundamental concept of horsemanship. Surprisingly, there is almost no quantitative evidence to support these beliefs.

OBJECTIVES

To assess the prevalence and heritability of conformational traits in Thoroughbred yearlings, and investigate their significance for subsequent turf flat-racing performance and durability.

METHODS

Nine selected conformational traits were assessed in a consistent, qualitative manner by a single veterinary observer and entered into a database together with details of pedigree and racing records.

RESULTS

Conformational data were collected from 3916 Thoroughbred yearlings sold at public auction during the 7 year period 1993-1999. Most of the horses (72%) raced in the UK in turf flat races; just 7% of the yearlings failed to race. Prevalence of conformational defects for the UK horses was reported, with turned out feet the most commonly recorded defect (30% of all horses). There was a tendency towards a greater proportion of horses with defects in the group of unraced horses compared with horses that raced, but this was not statistically significant. There were some significant associations between racing performance and conformational defects but these were found to be almost completely explained by an effect of sire. All of the conformational traits showed considerable evidence of genetic influence, with heritability indices ranging 0.16-1.00.

CONCLUSIONS AND POTENTIAL RELEVANCE

Overall, there were only weak associations between performance and conformation that could not be accounted for by the very strong relationship between pedigree and conformation. Further study of potential association between highly heritable conformation traits and racing durability and racing performance should be undertaken utilising validated, quantitative methods and technology.

Treatment of vasculitic peripheral neuropathy: a retrospective analysis of outcome

BACKGROUND

Vasculitis of the peripheral nervous system (PNS) is rare. There are no controlled treatment trials, and clinical practice is guided by experience from case series and indirectly by analogy with systemic vasculitis.

METHODS

We identified patients (n=212) with possible vasculitic peripheral neuropathy (VPN) from the neuropathology and neurophysiology records of two centres over 28 years. Case-notes were available for 181, from which, 106 cases of clinicopathological VPN were identified. Adequate treatment data were available in 100; follow-up data, in 93.

RESULTS

Of 106 cases, 95 had systemic vasculitis and 11 had vasculitis confined to the PNS. Pharmacological treatment (94/100 cases) was corticosteroid-based, and included cyclophosphamide in 54; 17 received additional agents. Initial stabilization was achieved in all but six. One-year survival was 90.3%. Of the nine who died in the first years (mean age 73 years), seven had received cyclophosphamide, and all but two had severe, multisystem vasculitis. The neurological relapse rate was 10%. Only one relapse occurred after cyclophosphamide treatment. Outcome was reported as good in 72% (78% in those who relapsed).

DISCUSSION

Death and relapse were infrequent in treated patients. Relapse occurred almost exclusively in patients treated with prednisolone alone. Aggressive early treatment with cyclophosphamide may prevent relapse. The current management approach to VPN appears largely effective, especially if cyclophosphamide is used.

Demyelinating diseases

A diagnosis of demyelination carries important therapeutic and prognostic implications. In most cases the diagnosis is made clinically, and involvement of the histopathologist is largely confined to postmortem confirmation and clinicopathological correlation. However, every now and then, accurate diagnosis of the presence or cause of demyelination before death hinges on the histopathological assessment. Recognition of demyelination depends on an awareness of this as a diagnostic possibility, and on the use of appropriate tinctorial and immunohistochemical stains to identify myelin, axons and inflammatory cells. In biopsy specimens, the critical distinction is usually from ischaemic or neoplastic disease, and the types of demyelinating disease most likely to be encountered are multiple sclerosis, acute-disseminated encephalomyelitis, progressive multifocal leucoencephalopathy and extrapontine myelinolysis. Interpretation of the pathology has to be made in the context of the clinical, radiological and biochemical findings. Freezing of a small amount of fresh tissue allows for later virological studies, and electron microscopy is occasionally helpful for demonstration of viral particles.

Evidence-based guidelines and decision support services: A discussion and evaluation in triple assessment of suspected breast cancer

Widespread health service goals to improve consistency and safety in patient care have prompted considerable investment in the development of evidence-based clinical guidelines. Computerised decision support (CDS) systems have been proposed as a means to implement guidelines in practice. This paper discusses the general concept in oncology and presents an evaluation of a CDS system to support triple assessment (TA) in breast cancer care. Balanced-block crossover experiment and questionnaire study. One stop clinic for symptomatic breast patients. Twenty-four practising breast clinicians from United Kingdom National Health Service hospitals. A web-based CDS system. Clinicians made significantly more deviations from guideline recommendations without decision support (60 out of 120 errors without CDS; 16 out of 120 errors with CDS, P<0.001). Ignoring minor deviations, 16 potentially critical errors arose in the no-decision-support arm of the trial compared with just one (P=0.001) when decision support was available. Opinions of participating clinicians towards the CDS tool became more positive after they had used it (P<0.025). The use of decision support capabilities in TA may yield significant measurable benefits for quality and safety of patient care. This is an important option for improving compliance with evidence-based practice guidelines.

Sucrose concentration in blood: a new method for assessment of gastric permeability in horses with gastric ulceration

A urine sucrose test has recently been reported to be a reliable method of detecting gastric ulcers in horses; however, technical difficulties associated with urine collection have limited the practical value of the test. The objective of this pilot study was to determine whether gastric sucrose permeability, as evaluated by serum sucrose concentration, could be used to detect gastric mucosal injury in horses. Twelve adult horses with naturally acquired gastric ulceration were studied. After a 20-hour nonfeeding period, each horse was dosed with 250 g of sucrose via nasogastric intubation. Blood samples were collected at 0, 15, 30, 45, 60, and 90 minutes, and horses underwent gastroscopy 4 hours later. The severity of gastric ulceration in each horse was defined by means of a 4-point ulcer-scoring system, and the relationship with serum sucrose concentration was analyzed by means of a linear mixed-effects model. Serum sucrose concentration was measured by liquid chromatography operating in tandem with electrospray mass spectrometry. After nasogastric administration of table sugar, horses with moderate to severe gastric ulceration had significant increase in serum sucrose concentration at 30, 45, 60, and 90 minutes, relative to earlier times (P < .05). Peak sucrose concentration was observed at 45 minutes, and was correlated with ulcer severity (Spearman's rank correlation coefficient = 0.898, P < .05). These data indicate that determination of sucrose concentration in equine serum may be a useful test for identifying horses with endoscopically visible gastric ulceration and has potential use as a noninvasive method for screening and monitoring horses engaged in racing training and other performance-related disciplines.

Central demyelination of the Vth nerve root in trigeminal neuralgia associated with vascular compression

We have examined the ultrastructure of the trigeminal sensory nerve root in three patients with medically intractable trigeminal neuralgia. In one patient, the nerve root was sandwiched between a large vein and a small pontine artery, in the others compression was due to marked dolichoectasia of a verterbal artery. Because these were not amenable to microvascular decompression, a caudal rhizotomy was performed, by excising a short inferior segment of nerve root in the region of indentation. In all cases, examination revealed a zone of chronic demyelination in the proximal (centrally myelinated) part of the root, near its junction with peripheral nerve. The zone of demyelination contained closely packed axons without intervening glial cytoplasm. Also present were small numbers of thinly myelinated axons. In some cases a single thin myelin sheath encircled several adjacent axons that were still in close apposition. These findings indicate that the trigeminal neuralgia associated with vascular compression is due to demyelination. The demyelination is associated with some evidence of remyelination. The latter phenomenon may account in part for the long periods of remission, especially during the initial period after the onset of trigeminal neuralgia. The partly aberrant nature of the myelination within the region of vascular compression may contribute to the persistence of symptoms in some patients after decompressive surgery.

Application of the 51Cr–EDTA urinary recovery test for assessment of intestinal permeability in the horse

Altered intestinal permeability is implicated in the pathogenesis of diverse equine medical conditions including alimentary laminitis and protein-losing enteropathies associated with parasitic infection. The aims of this study were to assess the feasibility of applying the 51Cr-EDTA absorption test for the assessment of intestinal permeability in the horse, and to apply this test in horses with experimentally induced alterations in gastrointestinal function. Four healthy ponies were administered 36 MBq of 51Cr-EDTA via naso-gastric tube, and urine samples were collected into polythene bags strapped to the pony's abdomen. Total urine voided every 6 h was collected during each test, and 1 ml samples were taken for measurement of gamma-radiation. Urinary recovery of 51Cr-EDTA was measured following intravenous atropine sulphate or bethanecol, and following 22 and 46 days of administration of 250,000 third-stage cyathostome larvae. There was no significant difference in urinary 51Cr-EDTA recovery following the control treatment, and following atropine or bethanecol administration, but significant increases were detected in the animals with experimental cyathostome infection consistent with increased permeability of the intestinal membrane. Motility modifying agents (bethanecol and atropine) did not affect absorption of 51Cr-EDTA, suggesting that subtle changes in motility might not affect the ability of this test to detect altered intestinal permeability. The finding of increased urinary recovery of 51Cr-EDTA in ponies with cyathostome infection suggests that 51Cr-EDTA may be a useful marker for assessment of intestinal permeability in the horse.

Contributors to white matter damage in the frontal lobe in Alzheimer's disease

Abnormalities of cerebral white matter are present in a majority of patients with Alzheimer's disease (AD) and probably contribute to motor dysfunction and cognitive impairment. The white matter abnormalities are usually attributed to degenerative vascular disease and cerebral amyloid angiopathy (CAA) but the evidence is scanty or inconclusive. In the present study we examined sections of frontal lobe from 125 autopsy-confirmed cases of AD and assessed the relationship of degenerative large and small vessel disease, CAA, parenchymal Abeta load and APOE genotype, to several objective measures of white matter damage: extent of immunolabelling for glial fibrillary acidic protein (GFAP), axonal accumulation of amyloid precursor protein (APP), axon density in superficial and deep white matter, and intensity of staining for myelin. We found no association between atherosclerosis, arteriolosclerosis, CAA or APOE genotype and white matter damage. However, labelling of white matter for GFAP correlated strongly with the parenchymal Abeta load (P = 0.0003) and with APP accumulation (P = 0.008). Our findings suggest that severity of frontal white matter damage in AD is closely related to parenchymal Abeta load and that in most cases the contribution of degenerative vascular disease, CAA and APOE is relatively minor.

Changes in bone mineral density, body composition and biochemical markers of bone turnover during weight gain in adolescents with severe anorexia nervosa: a 1-year prospective study

Osteoporosis is a serious complication of anorexia nervosa and in affected adolescents may result in a permanent deficit in bone mass. The pathophysiology of this bone disease has not been clearly defined. In this prospective study of 26 young women with anorexia nervosa aged 13-20 years (mean 16.5) we have measured changes in bone mineral density, total body composition and biochemical indices of bone turnover over 1 year. Over this period there was a mean weight gain of 10 kg and significant height gain with baseline and final values for body mass index of 14.2+/-1.7 and 17.6+/-2.3 kg/m2 (P<0.001). However, no significant changes were seen in bone mineral density in the spine or proximal femur during the study; total body bone mineral content was significantly higher than baseline at 3 months and 12 months (P=0.001 and P<0.0001), but total body bone mineral density at 3 months was significantly lower than baseline (P=0.003). Serum osteocalcin and bone-specific alkaline phosphatase values increased significantly and remained higher than baseline at all time points whereas urinary NTX/creatinine excretion showed a non-significant increase over the first 6 months of the study, but at 12 months, the mean value was significantly lower than baseline. Mean serum 25-hydroxyvitamin D levels showed a significant decrease at 6 months (P<0.05), but returned towards baseline thereafter. There was a significant increase in serum parathyroid hormone levels at all time points compared to baseline, these occurring within the normal range. These results indicate that although weight gain in young anorexics is associated with linear growth, bone mineral density does not increase. Whether this deficit can be corrected subsequently requires longer-term prospective studies.