[Decision making in veterinary practice]

OBJECTIVE

In daily practice, a veterinarian has to judge information and decide whether it can be adequately implemented for a given case. In this context, it is vital to base decisions on the most recent and reliable scientific findings. In Germany, every practitioner must take part in 20 to 40 hours annually of continuing education. To outline the current assessment and employment of evidence-based veterinary medicine (EBVM), we surveyed practitioners concerning continuing education and their skills in obtaining and evaluating scientific information.

MATERIALS AND METHODS

A survey amongst veterinary practitioners was conducted throughout five continuing education courses between May 2010 and November 2011. The questionnaire contained 32 questions concerning demographic data and profession (n = 4), qualification (n = 3), continuing education (n = 5) and skills related to EBVM (n = 20). Besides evaluating the statements of all participants, veterinarians were classified based on the type of practice and their statements compared.

RESULTS

In total, 293 questionnaires were returned. The majority of small animal practitioners (58.3%) and those working with food animals (54.9%) declared being capable of comprehending scientific talks or papers in English without difficulty. 10.4% of all practitioners neglected reading veterinary journals on a regular basis, while 20.8% stated they regularly read English veterinary journals. The majority of the practitioners sought advice from their employer or a colleague. They attributed a high or very high quality to both these information sources. Almost every participant (92.6%) stated that they consulted medical books, and 88.6% certified this information source as being of high or very high quality. 68.6% of the practitioners evaluated their skills in finding suitable literature as high or very high. However, only approximately half (52.1%) of all participants attributed themselves a high ability to evaluate the quality of the literature found.

CONCLUSION AND CLINICAL RELEVANCE

Most practitioners are very limited in their ability to assess the evidence of scientific information. Therefore, courses that introduce EBVM should be taught in both veterinary and postgraduate education to train critical appraisal of information and to support decision-making based on valid, clinically relevant data.

[Results of a survey regarding the publication of scientific results in German-speaking countries]

OBJECTIVE

Veterinarians should conduct diagnostic and therapeutic procedures according to the most recent and scientifically proven methods. Therefore, a rapid and effective transfer of scientific information is crucial. An important link between science and practice are findings published in scientific journals. The productivity of scientists is often measured referring to the number of papers published in reputable journals. Because many of these journals publish in the English language, it is possible that results from German research may never reach German veterinarians or only after a delay.

MATERIAL AND METHODS

Using an online questionnaire, faculty members (professors and scientific assistants) from Germany, Austria and Switzerland were asked how they had published their results during the previous 5 years. Furthermore, they were asked to identify the factors influencing their choice of journal for publication.

RESULTS

A total of 118 respondents completed the questionnaire. Nearly two thirds had published ten or more papers during the previous 5 years. More than half of these were published in the English language. Most participants consider the peer review process suitable for enhancing the quality of publications. The impact factor is seen as a fair indicator for the quality of a paper while considered an important factor for the choice of a journal for publication of the respondents own results.

CONCLUSION AND CLINICAL RELEVANCE

According to the data, respondents prefer to publish their results in the English language and in journals with a high impact factor. Therefore, veterinarians may never receive this information via German journals or only after a delay. One possible solution could be a regularly published practice-oriented compilation of relevant scientific findings.

Association of N-acetylaspartate and cerebrospinal fluid Aβ42 in dementia

The interplay of amyloid and mitochondrial function is considered crucial in the pathophysiology of Alzheimer's disease (AD). We tested the association of the putative marker of mitochondrial function N-acetylaspartate (NAA) as measured by proton magnetic resonance spectroscopy within the medial temporal lobe and cerebrospinal fluid amyoid-β42 (Aβ42), total Tau and pTau181. 109 patients were recruited in a multicenter study (40 mild AD patients, 14 non-AD dementia patients, 29 mild cognitive impairment (MCI) AD-type patients, 26 MCI of non-AD type patients). NAA correlated with Aβ42 within the AD group. Since the NAA concentration is coupled to neuronal mitochondrial function, the correlation between NAA and Aβ42 may reflect the interaction between disrupted mitochondrial pathways and amyloid production.

Novel APP/Aβ mutation K16N produces highly toxic heteromeric Aβ oligomers

Here, we describe a novel missense mutation in the amyloid precursor protein (APP) causing a lysine-to-asparagine substitution at position 687 (APP770; herein, referred to as K16N according to amyloid-β (Aβ) numbering) resulting in an early onset dementia with an autosomal dominant inheritance pattern. The K16N mutation is located exactly at the α-secretase cleavage site and influences both APP and Aβ. First, due to the K16N mutation APP secretion is affected and a higher amount of Aβ peptides is being produced. Second, Aβ peptides carrying the K16N mutation are unique in that the peptide itself is not harmful to neuronal cells. Severe toxicity, however, is evident upon equimolar mixture of wt and mutant peptides, mimicking the heterozygous state of the subject. Furthermore, Aβ42 K16N inhibits fibril formation of Aβ42 wild-type. Even more, Aβ42 K16N peptides are protected against clearance activity by the major Aβ-degrading enzyme neprilysin. Thus the mutation characterized here harbours a combination of risk factors that synergistically may contribute to the development of early onset Alzheimer disease.

[Evidence based medicine in veterinary daily practice]

The veterinary practitioner should base decisions concerning diagnostic procedures and treatments in practice on recent, valid and clinically relevant information. He may rely on journal papers, colleagues, the internet or other sources. It is a great challenge to find appropriate information in a reasonable time. Furthermore, the practitioner has to judge the information regarding its actuality and validity. Ideally, such information should provide a high level of evidence. This means that this information is more likely to be "correct". Good information can be obtained through high quality trials, such as randomized and blinded controlled clinical trials. Universities, publishers and professional organizations should promote editing of scientific information to support practitioners in decision making.

Peptide fingerprinting of Alzheimer's disease in cerebrospinal fluid: identification and prospective evaluation of new synaptic biomarkers

Background

Today, dementias are diagnosed late in the course of disease. Future treatments have to start earlier in the disease process to avoid disability requiring new diagnostic tools. The objective of this study is to develop a new method for the differential diagnosis and identification of new biomarkers of Alzheimer's disease (AD) using capillary-electrophoresis coupled to mass-spectrometry (CE-MS) and to assess the potential of early diagnosis of AD.

Methods and Findings

Cerebrospinal fluid (CSF) of 159 out-patients of a memory-clinic at a University Hospital suffering from neurodegenerative disorders and 17 cognitively-healthy controls was used to create differential peptide pattern for dementias and prospective blinded-comparison of sensitivity and specificity for AD diagnosis against the Criterion standard in a naturalistic prospective sample of patients. Sensitivity and specificity of the new method compared to standard diagnostic procedures and identification of new putative biomarkers for AD was the main outcome measure. CE-MS was used to reliably detect 1104 low-molecular-weight peptides in CSF. Training-sets of patients with clinically secured sporadic Alzheimer's disease, frontotemporal dementia, and cognitively healthy controls allowed establishing discriminative biomarker pattern for diagnosis of AD. This pattern was already detectable in patients with mild cognitive impairment (MCI). The AD-pattern was tested in a prospective sample of patients (n = 100) and AD was diagnosed with a sensitivity of 87% and a specificity of 83%. Using CSF measurements of beta-amyloid1-42, total-tau, and phospho₁₈₁-tau, AD-diagnosis had a sensitivity of 88% and a specificity of 67% in the same sample. Sequence analysis of the discriminating biomarkers identified fragments of synaptic proteins like proSAAS, apolipoprotein J, neurosecretory protein VGF, phospholemman, and chromogranin A.

Conclusions

The method may allow early differential diagnosis of various dementias using specific peptide fingerprints and identification of incipient AD in patients suffering from MCI. Identified biomarkers facilitate face validity for the use in AD diagnosis.

Atrophy outcomes in multicentre clinical trials on Alzheimer's disease: effect of different processing and analysis approaches on sample sizes

Structural MRI markers may serve as surrogate endpoints in clinical trials on disease modification in Alzheimer's disease (AD). Here, we used a longitudinal MRI data set of total brain and cortical grey matter volumes from 66 patients with AD recruited across seven centres of the German Dementia Competence Network. We compared effect size estimates for the detection of a 25% reduction of atrophy progression between a priori segmentation of brain tissue, implementing an anatomical model of brain tissue distribution, and a posteriori segmentation that was not informed by an anatomical model. Additionally, we compared effect size estimates between fixed effects analysis and a mixed effects model, implementing a random effects term to account for variable spacing of observation times. A priori segmentation reduced the required sample size by 50%. Introducing a random effects term for time led to an additional 50% reduction of required samples sizes compared to fixed effects analysis. In summary, using a priori segmentation with mixed effects analysis reduced the sample size to detect clinically relevant treatment effects more than fourfold. The implementation of mixed effects models will enhance the power to detect treatment effects also with other classes of biological endpoints including molecular biomarkers of disease.

[Inappropriate lactation syndrome in goats--case collection and experiences with mastectomy]

OBJECTIVE

Hobby keeping of goats and sheep confronts veterinarians with new challenges that rarely have to be faced in livestock husbandry. During the last five years five goats were presented to the Clinic for Animal Reproduction, Faculty of Veterinary Medicine, Freie Universität Berlin, Germany, with inappropriate lactation syndrome. Four of these animals had been previously treated with cabergoline without enduring success. According to the request of the owners (informed consent) and the clinical severity of the cases, a mastectomy was performed in all five animals.

MATERIAL AND METHODS

Surgery was performed under general anaesthesia using ketamine and xylazine, and with the patients in a recumbent position.

RESULTS

Mastectomy in small ruminants requires knowledge of the anatomy of the udder and the possible positions of the supplying blood vessels. Our patients displayed a variety of dispositions of the Vena epigastrica caudalis superficialis. Special attention should be paid to a careful and blunt dissection of the mammary gland, and immediate control of haemorrhage, to maintain a clear view on the anatomic structures. Furthermore, dissection of the glandular tissue should be strictly avoided to prevent milk contamination of the surgical area. A sufficient skin flap has to be left to cover the surgical area after removal of the udder.

CONCLUSION AND CLINICAL RELEVANCE

Even though udder amputation appears to be a radical and high-risk procedure, all five goats survived the surgery. The wound healing occurred in a reasonable time without any severe complications. In goats that are kept as "hobby animals" and in which an inappropriate lactation syndrome cannot be treated conservatively, mastectomy is a reasonable and promising therapy.

[Validity of the use of L-Tyrosine to enhance fertility of female domestic animals. A study on the evidence from the literature]

OBJECTIVE

In order to improve fertility in female domestic animals, especially in bitches, several authors recommend the feeding of the amino acid L-Tyrosine during the follicular phase of the oestrous cycle. The aim of this article was a systematic and statistical analysis of current literature in terms of evidence-based medicine.

MATERIALS AND METHODS

Literature research, statistical analysis and classification in levels of evidence.

RESULTS

Fifteen German and two English studies on the effect of L-Tyrosine on the fertility in domestic animals were found. The statistical analysis and evaluation of evidence showed that most studies feature methodical deficits and often findings were inconsistent with one another.

CONCLUSION AND CLINICAL RELEVANCE

Heterogeneous results indicate a considerable need for further research on the effectiveness and dose of L-Tyrosine to legitimate its appliance in practice.

Lactatio falsa bei der Ziege – Fallsammlung und Erfahrungen mit der Amputation des Gesäuges

Gegenstand: Die Haltung von Schafen und Ziegen als Hobbytiere konfrontiert Tierärzte mitunter mit Problemen, die bei einer reinen Nutztierhaltung eher selten vorkommen. In den letzten 5 Jahren wurden der Tierklinik für Fortpflanzung der FU Berlin fünf Ziegen aus Hobbyhaltungen mit rezidivierender Lactatio falsa vorgestellt. Vier Tiere waren in der Vergangenheit bereits mit Cabergolin mit ausbleibendem oder nur kurzfristigem Erfolg behandelt worden. Aufgrund der Größe des Euters wurde auf Wunsch der Besitzer bei allen fünf Ziegen eine Euteramputation vorgenommen. Material und Methoden: Der operative Eingriff erfolgte unter Allgemeinanästhesie mit Ketamin und Xylazin in Rückenlage der Patienten. Ergebnisse: Die durchgeführte Anästhesie erwies sich für den Eingriff als geeignet. Die Mastektomie bei Ziegen erfordert spezielle Kenntnisse hinsichtlich der Anatomie der Milchdrüse und ihrer versorgenden Gefäße. Bei den fünf Patienten war eine teils unterschiedliche Anlage der Vena epigastrica caudalis superficialis festzustellen. Bei der Operation zu beachten sind insbesondere das vorsichtige und stumpfe Präparieren und eine schnelle Blutstillung, um ein übersicht - liches Operationsfeld zu erhalten. Die Eröffnung von Zisternen oder Drüsengewebe sollte vermieden werden, damit keine Milch austritt, da daraus Wundheilungsstörungen entstehen könnten. Ein ausreichender Hautlappen für den späteren Wundverschluss muss belassen werden. Schlussfolgerung und klinische Relevanz: Alle fünf Ziegen überstanden die Operation ohne Komplikationen. Die Wunden heilten schnell und nahezu ohne Probleme. Für als Hobbytiere gehaltene Ziegen mit Lactatio falsa, die konservativ nicht therapiert werden können, stellt die Mastektomie eine sinnvolle, erfolgversprechende Behand - lung dar.

Multicentre variability of MRI-based medial temporal lobe volumetry in Alzheimer's disease

Magnetic resonance imaging (MRI)-based volumetry of medial temporal lobe regions is among the best established biomarker candidates of Alzheimer's disease (AD) to date. This study assessed the effect of multicentre variability of MRI-based hippocampus and amygdala volumetry on the discrimination between patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) and on the association of morphological changes with ApoE4 genotype and cognition. We studied 113 patients with clinically probable AD and 150 patients with amnestic MCI using high-resolution MRI scans obtained at 12 clinical sites. We determined effect sizes of group discrimination and random effects linear models, considering multicentre variability. Hippocampus and amygdala volumes were significantly reduced in AD compared with MCI patients using data pooled across centres. Multicentre variability did not significantly affect the power to detect a volume difference between AD and MCI patients. Among cognitive measures, delayed recall of verbal and non-verbal material was significantly correlated with hippocampus and amygdala volumes. Amygdala and hippocampus volumes were not associated with ApoE4 genotype in AD or MCI. Our data indicate that multicentre acquisition of MRI data using manual volumetry is reliable and feasible for cross-sectional diagnostic studies, and they replicate essential findings from smaller scale monocentre studies.

Efficacy of homeopathic remedies as prophylaxis of bovine endometritis

The objective of this study was to evaluate the efficacy of 2 different homeopathic prophylactic strategies for the prevention of endometritis. The drugs used were Lachesis compositum (Lachesis), Carduus compositum (Carduus), and Traumeel LT (Traumeel). Each drug contained a mixed formula of homeopathic remedies. All 929 cows received the first treatment within 24 h postpartum. The second to fourth treatments were conducted at 7 to 13, 14 to 20, and 21 to 27 d in milk, respectively. In the first group, the 4 treatments were Traumeel, Lachesis, Carduus, and Carduus, respectively (n = 206). In the second group, Lachesis was administered 3 times, followed by 1 treatment with Carduus (n = 198). The control group received 4 injections of saline (n = 189). In the fourth week after calving, the prevalence of clinical endometritis, uterine involution, and ovarian activity was monitored by rectal palpation and by ultrasonography. To assess the resumption of ovarian activity, blood samples were taken to determine the concentration of serum progesterone. The concentrations of beta-hydroxybutyrate and nonesterified fatty acids in blood serum were examined to evaluate energy metabolism. The incidence of clinical endometritis at 21 to 27 d in milk did not differ between the groups (44.4, 44.8, and 36.9% in the Traumeel, Lachesis, Carduus, and Carduus group; the 3x Lachesis, followed by Carduus group; and the control group, respectively). The proportion of cows with cyclic activity at 21 to 27 d in milk and the proportion of cows above threshold values of progesterone, beta-hydroxybutyrate, and nonesterified fatty acids did not differ significantly between groups. When reproductive performance data were analyzed, no significant differences were found between groups. Hence, the treatment protocols tested were not effective in preventing bovine endometritis or in enhancing reproductive performance in this study.

Influence of different oral rehydration solutions on abomasal conditions and the acid-base status of suckling calves

The aim of the study was to investigate the influence of oral rehydration solutions (ORS) on milk clotting, abomasal pH, electrolyte concentrations, and osmolality, as well as on the acid-base status in blood of suckling calves, as treatment with ORS is the most common therapy of diarrhea in calves to correct dehydration and metabolic acidosis. Oral rehydration solutions are suspected to inhibit abomasal clotting of milk; however, it is recommended to continue feeding cow's milk or milk replacer (MR) to diarrheic calves to prevent body weight losses. Three calves with abomasal cannulas were fed MR, MR-ORS mixtures, or water-ORS mixtures, respectively. Samples of abomasal fluid were taken before and after feeding at various time points, and pH, electrolyte concentrations, and osmolality were measured. The interference of ORS with milk clotting was examined in vivo and in vitro. To evaluate the effects of ORS on systemic acid-base status, the Stewart variables strong ion difference ([SID]), acid total ([A(tot)]), and partial pressure of CO2 (pCO2) were quantified in venous blood samples drawn before and after feeding. Calves reached higher abomasal pH values when fed with MR-ORS mixtures than when fed MR. Preprandial pH values were re-established after 4 to 6 h. Oral rehydration solutions prepared in water increased the abomasal fluid pH only for 1 to 2 h. Oral rehydration solutions with high [SID(3)] ([Na(+)] + [K(+)] - [Cl(-)]) values produced significantly higher abomasal pH values and area under the curve data of the pH time course. Caseinomacropeptide, an indicator of successful enzymatic milk clotting, could be identified in every sample of abomasal fluid after feeding MR-ORS mixtures. The MR-ORS mixtures with [SID(3)] values > or =92 mmol/L increased serum [SID(3)] but did not change venous blood pH. Oral rehydration solutions do not interfere with milk clotting in the abomasum and can, therefore, be administered with milk. In this study, MR-ORS mixtures with high [SID(3)] values caused an increase of serum [SID(3)] in healthy suckling calves and may be an effective treatment for metabolic acidosis in calves suffering from diarrhea.

Association between FDG uptake, CSF biomarkers and cognitive performance in patients with probable Alzheimer's disease

PURPOSE

Brain imaging of FDG uptake and cerebrospinal fluid (CSF) concentration of amyloid-beta 1-42 (Abeta(1-42)) or tau proteins are promising biomarkers in the diagnosis of Alzheimer's disease (AD). There is still uncertainty regarding any association between decreased FDG uptake and alterations in CSF markers.

METHODS

The relationship between FDG uptake, CSF Abeta(1-42) and total tau (T-tau), as well as the Mini-Mental State Examination (MMSE) score was investigated in 34 subjects with probable AD using step-wise linear regression. FDG uptake was scaled to the pons.

RESULTS

Scaled FDG uptake was significantly reduced in the probable AD subjects compared to 17 controls bilaterally in the precuneus/posterior cingulate area, angular gyrus/inferior parietal cortex, inferior temporal/midtemporal cortex, midfrontal cortex, and left caudate. Voxel-based single-subject analysis of the probable AD subjects at p < 0.001 (uncorrected) revealed a total volume of significant hypometabolism ranging from 0 to 452 ml (median 70 ml). The total hypometabolic volume was negatively correlated with the MMSE score, but it was not correlated with the CSF measures. VOI-based step-wise linear regression revealed that scaled FDG uptake in the precuneus/posterior cingulate was negatively correlated with CSF Abeta(1-42). Scaled FDG uptake in the caudate was positively correlated with CSF T-tau.

CONCLUSION

The extent and local severity of the reduction in FDG uptake in probable AD subjects are associated with cognitive impairment. In addition, there appears to be a relationship between local FDG uptake and CSF biomarkers which differs between different brain regions.

Adherence to medication in patients with dementia: predictors and strategies for improvement

Measures to facilitate patient medication adherence should be considered an integral part of the comprehensive care of older patients with multiple diseases. However, impairment of cognitive functions and dementia, in particular, may substantially compromise adherence behaviour. Therefore, a literature review was performed to identify factors associated with adherence to medication in patients with cognitive impairment or dementia, and to discuss strategies for improvement of non-adherence. Evidence-based information on how to deal with adherence to medication in patients with dementia is scarce because of a lack of specific studies. However, there is increasing knowledge about factors influencing medication adherence behaviour in older age, and emerging insight into the relationships between adherence behaviour and cognitive capacity, memory and executive function, in particular. Nevertheless, understanding elderly persons' strategies for maintaining regular use of even complex drug regimens is still limited. Progress of research in this field is needed. It is notable that measures to improve adherence consist of combinations of educational interventions and cognitive support but assessment of study participants' cognitive function is rare. In clinical practice, awareness of non-adherence as a result of cognitive impairment is relatively low. The most important step is early detection of cognitive impairment when this is impacting negatively on medication management. A practical geriatric screening test is recommended to identify memory problems and further functional impairments associated with cognitive impairment. Performance-based assessments might be useful for screening medication management capacity, in addition to a careful drug history, inspection of all medicines used (including over-the-counter drugs) and proxy information. However, no feasible screening methods have as yet found their way into clinical practice. Patients with impaired executive function, lack of awareness of illness and personality traits such as independency and high self-confidence may be at particular risk of non-adherence. The question is when to switch patient medication self-management to another person's responsibility if cognitive decline progresses. Further research is needed on measures to differentiate cognitive function and the relationships between memory concerns, memory strategy use and medication management. Also, studies evaluating the influence of personal support, health status and depression on the memory strategies used are needed. It is important to assess patients' attitudes toward medication and their relationship with proxies. Strategies for facilitating medication adherence in patients with dementia include prescribing as few medicines as possible, tailoring dose regimens to personal habits, and coordinating all drug dosing schedules as much as possible. When providing medication organizers, it is important to observe the patient's ability to use devices appropriately. In addition, automated computer-based reminding aids, online medication monitoring and telemonitoring may be helpful for patients with mild dementia. The decision as to when assistance with medication self-management is needed has to be made taking into account patient independency and safety aspects. This holds true for medicines with a narrow therapeutic range, in particular. Interactions among the individual patient's cognitive status, mood, level of self-efficacy and particular living situation must also be taken into consideration when searching for the optimal medication adherence strategy. No evidence-based recommendations can be given as yet. However, comprehensive assessment of the individual patient and careful consideration of all potential drug-related problems will probably help facilitate adherence and prevent compromised health outcomes in patients with dementia.

Asymmetrical dimethylarginine is increased in plasma and decreased in cerebrospinal fluid of patients with Alzheimer's disease

BACKGROUND

Asymmetrical dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthase and may alter NO production during pathological conditions. Concerning Alzheimer's disease (AD), there are reports on altered cerebral NO metabolism, but only few studies on ADMA concentrations in plasma and cerebrospinal fluid (CSF).

METHODS

We assessed plasma ADMA in 80 AD patients and 80 age- and gender-matched controls and CSF ADMA in a subgroup of 53 AD patients and 20 controls.

RESULTS

ADMA plasma concentrations were increased, while CSF ADMA concentrations were decreased in AD patients. There was a significant association between decreasing CSF ADMA levels and the severity of cognitive impairment.

CONCLUSION

Elevated ADMA in plasma might be a contributing factor for AD through alterations of NO metabolism, for example decreased cerebral microperfusion, while decreased levels of CSF ADMA might lead to a cerebral increase of NO, peroxynitrite production and oxidative protein damage. Our study reveals different mechanisms of plasma and CSF ADMA regulation, both potentially contributing to AD pathology.