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Biomedical subjects

A Aeschlimann

Publications and source records attributed to A Aeschlimann.

At least 19 recordsLinked to original sources
PubMed2002

Distribution, density and migration dynamics of Ixodes ricinus in an area of the Jurassic mountains of Switzerland.

In an area of the Jurassic mountains of Switzerland ecological aspects of the tick species Ixodes ricinus were studied. In particular, the influence of temperature, humidity and vegetation parameters on tick density and distribution were investigated several times in six different habitat types. This was carried out on two scales; on a small scale, within a habitat type and on a larger scale, where all six habitat types were included. By a marking experiment, aspects of the migration dynamics of the ticks were studied. The densities of the six habitat types differed significantly in most of the cases. An analysis of the distribution pattern within a habitat type showed a contagious distribution mostly for the forests and the forest edge, whereas a random distribution was found as well, mainly for the meadows. But these distribution patterns tend towards randomness with time. On a small scale none of the factors showed an influence on tick distribution, therefore the most important factor on this scale might be the hosts of Ixodes ricinus. On a larger scale, temperature and humidity do in some cases influence tick densities. The marking experiment suggests an extremely high turnover of the ticks in an area with an average host density, probably due to passive transportation by hosts and to activation of resting individuals.

Altitude↗
PubMed2001

Smallest detectable and minimal clinically important differences of rehabilitation intervention with their implications for required sample sizes using WOMAC and SF-36 quality of life measurement instruments in patients with osteoarthritis of the lower extremities.

OBJECTIVE: To discuss the concepts of the minimal clinically important difference (MCID) and the smallest detectable difference (SDD) and to examine their relation to required sample sizes for future studies using concrete data of the condition-specific Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the generic Medical Outcomes Study 36-Item Short Form (SF-36) in patients with osteoarthritis of the lower extremities undergoing a comprehensive inpatient rehabilitation intervention. METHODS: SDD and MCID were determined in a prospective study of 122 patients before a comprehensive inpatient rehabilitation intervention and at the 3-month followup. MCID was assessed by the transition method. Required SDD and sample sizes were determined by applying normal approximation and taking into account the calculation of power. RESULTS: In the WOMAC sections the SDD and MCID ranged from 0.51 to 1.33 points (scale 0 to 10), and in the SF-36 sections the SDD and MCID ranged from 2.0 to 7.8 points (scale 0 to 100). Both questionnaires showed 2 moderately responsive sections that led to required sample sizes of 40 to 325 per treatment arm for a clinical study with unpaired data or total for paired followup data. CONCLUSION: In rehabilitation intervention, effects larger than 12% of baseline score (6% of maximal score) can be attained and detected as MCID by the transition method in both the WOMAC and the SF-36. Effects of this size lead to reasonable sample sizes for future studies lying below n = 300. The same holds true for moderately responsive questionnaire sections with effect sizes higher than 0.25. When designing studies, assumed effects below the MCID may be detectable but are clinically meaningless.

Aged↗
PubMed2001

Multiple choice question quiz: a valid test for needs assessment in CME in rheumatology and for self assessment.

Drawing from experience in Switzerland, a test of 60 multiple choice questions covering the entire area of rheumatology was constructed and used at the international symposium of rheumatology, EULAR, Geneva 1998. It was introduced as a multiple choice question game, the language was English, and the level of acceptance was very high. Language posed only occasional problems. The reliability of the test for internal consistency was high (Cronbach alpha 0.852). One of the main target groups, the private practitioners, was the largest group of rheumatologists (nearly 50%). Evaluative statements of the participants indicate that it was a highly relevant test for rheumatology. This test is a valuable way for needs assessment in continuing medical education and for self assessment. Importantly, it has been shown that such a test can be conducted at an international level.

Analysis of Variance↗
PubMed2001

Responsiveness of the WOMAC osteoarthritis index as compared with the SF-36 in patients with osteoarthritis of the legs undergoing a comprehensive rehabilitation intervention.

OBJECTIVE: To compare the responsiveness of the condition-specific Western Ontario and McMaster Universities osteoarthritis (OA) index (WOMAC) and the generic Short Form-36 (SF-36) in patients with OA of the legs undergoing a comprehensive inpatient rehabilitation intervention. METHODS: A prospective follow up study of consecutively referred inpatients of a rehabilitation clinic was made. The patients included fulfilled the American College of Rheumatology criteria for knee or hip OA and underwent both passive and, particularly, active physical therapy for three to four weeks. Responsiveness assessment was performed using the standardised response mean (SRM), effect size, and Guyatt's responsiveness statistic between admission and discharge (end of rehabilitation) and then again between admission and three months later. For pain and function the SRMs were stratified by sex and OA joint. Effects were tested by the t test and SRMs of different scales were compared by the jack knife test. RESULTS: At the three month follow up, complete data were obtained for 223 patients. In general, the three responsiveness statistics showed a similar order of responsiveness. For both instruments, the pain scales were more responsive than the function scales. The responsiveness of the pain scale of both instruments was comparable (SRM=0.723 for WOMAC and SRM=0.528 for SF-36 at the end of rehabilitation; SRM=0.377 for WOMAC and SRM=0.468 for SF-36 at the three month follow up). In the measurement of function, the WOMAC was significantly more responsive than the SF-36 (SRMs, end of rehabilitation: 0.628 v 0.249; three month follow up: 0.235 v -0.001). Responsiveness tended to be higher in women and in knee OA than in men and hip OA. CONCLUSIONS: Both instruments, the WOMAC and the SF-36, capture improvement in pain in patients undergoing comprehensive inpatient rehabilitation intervention. Functional improvement can be detected better by the WOMAC than by the SF-36. All the other scales of both instruments were more weakly responsive.

Adult↗
PubMed2000

[Vasculitis and mononeuritis multiplex].

In 1991, a 67 year old patient, suffering from an adenocarcinoma of the colon, had to undergo hemicolectomy. In the five following years, isolated metastases developed in the liver and have been surgically removed. In 1997, acute mononeuritis multiplex appeared and nerve biopsy revealed vasculitis. There were no signs of inflammatory rheumatic illness, collagenosis, cryglobulinemia, infection or hypersensitivity to medication. We have therefore postulated a relation between the vasculitis and the malignancy. Tumorous relapse could however not be detected at that time. Under immunosuppressive therapy, the neurological deficiencies receded partially, though the carcinoma of the colon reappeared with systemic metastases in the wake of the vasculitis. Diagnostic measures and the relationship between malignancy and vasculitis are discussed.

Adenocarcinoma↗
PubMed1999

A new look at the Western Ontario and McMaster Universities Osteoarthritis Index using Rasch analysis.

OBJECTIVE: The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) is a valid and widely used instrument for the assessment of osteoarthritis patients. We examined whether applying Rasch analysis, a new item-response theory, supports its metric properties. METHODS: The metric properties were examined in a cohort of patients with osteoarthritis of the hip or knee. In an exploratory approach, a validated German version of the WOMAC was analyzed using Rasch analysis for its unidimensionality and construct definition. RESULTS: One hundred fifty-eight patients were included in the study. The 3 WOMAC domains--pain, stiffness, and physical function--were unidimensional when examined separately. In an analysis including all items, the stiffness items did not fit the model. This indicates that they are distinct from the pain and function items. Item difficulty analyses revealed redundancy between corresponding pain and function items addressing the same task (e.g., "pain while standing upright" and "difficulty while standing"). CONCLUSION: Applying Rasch analysis to the 3 WOMAC domains confirms their unidimensionality. However, the pain and function items seem to represent the same construct. Thus, it may be possible to simplify these domains to avoid redundancy. The impact of reducing items must nevertheless be examined.

Activities of Daily Living↗
PubMed1998

Still's disease in children and adults: a distinct pattern of acute-phase proteins.

Crossed affinoimmunoelectrophoresis with Con A as a ligand was used to examine the microheterogeneity of alpha1-acid glycoprotein (AGP) and alpha1-antichymotrypsin (ACT) in sera of patients with child-onset and adult-onset Still's disease. The reactivity of both proteins was increased in sera of adults and decreased in sera of children with active disease, when compared with normal values. We also found statistically significant differences in serum concentration of ACT and ferritin in both diseases. This result suggests different pathogenic mechanisms of Still's disease in children and adults. Serum concentration of ferritin and ACT could be of value as a combined marker for the adult, but not the juvenile form of Still's disease.

Adolescent↗
PubMed1998

Longitudinal study of Lyme borreliosis in a high risk population in Switzerland.

Orienteers from all parts of Switzerland (n = 416) were included in a longitudinal study for Lyme borreliosis. In spring 1986, the seroprevalence was 28.1%. At the beginning of the study, 84.3% of orienteers reported a history of tick bite, and 3.8% reported a past history of Lyme borreliosis. During the first (spring 1986-autumn 1986), second (autumn 1986-spring 1987) and third (spring 1987-autumn 1987) period, rates of seroconversion were 0.6%, 2.7% and 2.1% respectively. During the first and second period, clinical incidence were 1.0% and 0.25% respectively. No active Lyme borreliosis was detected during the third period. Among orienteers who seroconverted during the study (n = 16), only two developed clinical symptoms. Hence, Borrelia burgdorferi infection is often asymptomatic.

Adult↗
PubMed1997

Population genetic structure of Ixodes ricinus in Switzerland from allozymic data: no evidence of divergence between nearby sites.

Ixodes ricinus is a vector and reservoir of numerous infectious agents, especially Borrelia burgdorferi, the agent of Lyme disease. In Switzerland, its ecology and physiology have been well studied. Moreover, the foci of some infectious agents transmitted by this tick are identified. They can display relatively to extremely small geographical size depending on the diseases considered. In order to understand how the gene flows occur and to characterise the genetic structure of Ixodes ricinus populations, we used an indirect method based on genetic markers: allozymes. The sampling was carried out in 5 localities. Eighteen loci were analysed and 2 appeared polymorphic. This shows the low allozymic variability displayed by Ixodes ricinus. Based on these 2 loci, the populations appeared panmictic in Switzerland. This may be explained by the wide range of vertebrate species this tick can infest, especially birds. However, the result is surprising if we consider the extreme localisation of the foci of some infectious agents. We conclude that more powerful genetic markers could be used in order to better understand the epidemiology of tick-borne diseases in Switzerland.

Alleles↗
PubMed1996

[Current didactic concepts--243 participants evaluate Rheuma 2000].

The Swiss League against Rheumatic diseases in collaboration with rheumatologists organized a special educational program for general practitioners. An evaluation questionnaire was filled in by 238 of the 243 participants. With an average value of 4.57 points out of possible 5.0 the new educational concept was very successful. The interactive learning process in small groups seems to be a good alternative to formal lectures.

Education, Medical, Continuing↗
PubMed1996

Ticks of domestic animals in the Macedonia region of Greece.

A study was carried out on ticks of domestic animals in the Macedonia region of Greece. During 1983-1986, 11,620 tick specimens, belonging to 18 species and subspecies, were collected from cattle, sheep, goats and dogs, in 64 localities throughout Macedonia. Rhipicephalus bursa, the most common tick, and Hyalomma marginatum marginatum occurred in all bioclimatic zones, as well as the two one-host ticks, Boophilus annulatus and H. detritum scupense, which were present in fewer localities. R. turanicus, R. sanguineus, Ixodes gibbosus and H. anatolicum excavatum occurred essentially in the mesomediterranean bioclimatic zone. I. ricinus, Dermacentor marginatus and Haemaphysalis ticks (Hm. inermis, Hm. punctata, Hm. sulcata, Hm. parva) were found frequently in the biotopes of the attenuated mesomediterranean and submediterranean bioclimates. Rhipicephalus adults and the two-host Hyalomma ticks were active in the spring-summer period. Ixodes spp., Haemaphysalis spp., D. marginatus, as well as H. detritum scupense and the immature stages of R. bursa appeared during autumn and winter. Hyalomma and Boophilus ticks fed mainly on cattle. R. sanguineus almost exclusively parasitized dogs, which were also the only hosts from which I. hexagonus has been collected. The infestations were generally weak or moderate. Few heavy infestations were observed on cattle, especially in autumn. Most of the tick species showed a strong preference for some particular sites on the vertebrate body. This predilection could vary according to the host species.

Animals↗
PubMed1996

[Histopathological analysis of bovine livers infested by Dicrocoelium dendriticum].

The object of this study was to determine the evolution of the lesions provoked by dicrocoeliasis in hepatic tissue, as a function of the quantity of parasites. Of the 274 bovine livers taken from the slaughterhouse and autopsied for Dicrocoelium dendriticum infection, 191 demonstrated hepatic lesions that revealed a proliferation of bile ducts, modifications of the bile ducts and hepatic fibrosis lesions. The modifications of the surfaces of the bile ducts and the hepatic fibrosis lesions increased with the level of infestation from 0 to 300 D dendriticum. Above these values, 301 to 600 flukes, a decrease was observed.

Animals↗
PubMed1995

[Reiter's disease--a review of an interdisciplinary disease].

Over the past 20 years the term 'Reiter's disease' has been expanded from the classical triad of sterile urethritis, conjunctivitis and arthritis to include a broader range of reactive arthritides. Indeed, the classical syndrome as described by Reiter is rarely seen in its complete form, and the presence or absence of active infection in the joint is being redefined in the light of recent techniques of molecular biology. The terminology of Reiter's syndrome, reactive arthritis and seronegative spondylarthropathy are defined here using case examples.

Adult↗
PubMed1995

Biology of Ixodes (Pholeoixodes) hexagonus under laboratory conditions. Part II. Effect of mating on feeding and fecundity of females.

The effect of mating on the feeding and fecundity of Ixodes (Pholeoixodes) hexagonus females was studied under controlled laboratory conditions of 22-23 degrees C and 98% relative humidity. The feeding period of mated females was 6-15 days and 11-13 days for unmated females. The mean weight of the engorged mated females was 114.84 +/- 45.89 mg, whereas, that of the engorged unmated females was significantly lower (80.61 +/- 28.84 mg). During the initial slow feeding period, the weight of mated females increased 6.6 times. At the end of the blood feeding, they had increased their initial weight 35.5 times. Unmated females never entered the rapid engorgement phase and up to 12 days of feeding period their mean weight did not increase more than 9.2 times. The pre-oviposition periods of mated and unmated females were 6-15 days and 4-12 days, respectively. The mean of the egg production efficiency was 40.26 +/- 12.47% for mated females and 35.68 +/- 12.2% for unmated females. The mean of the mass conversion efficiency was 73.6 +/- 13.7% for mated females and 66.48 +/- 16.55% for unmated females. Sixty per cent of the eggs deposited by mated females hatched whereas only 1% of the eggs deposited by unmated females hatched. These results indicate that I. hexagonus females possess some predisposition for parthenogenesis and only fertility and not fecundity depends on mating.

Animals↗
PubMed1995

Pathogenicity of Steinernema carpocapsae and S. glaseri (Nematoda: Steinernematidae) to Ixodes scapularis (Acari: Ixodidae).

The entomopathogenic nematodes Steinernema carpocapsae (Weiser) and S. glaseri (Steiner) are pathogenic to engorged adult, blacklegged ticks, Ixodes scapularis (Say), but not to unfed females, engorged nymphs, or engorged larvae. Nematodes apparently enter the tick through the genital pore, thus precluding infection of immature ticks. The timing of tick mortality, and overall mortality after 17 d, did not differ between infections by S. carpocapsae and S. glaseri. These nematodes typically do not complete their life cycles or produce infective juveniles in I. scapularis. However, both species successfully produced infective juveniles when the tick body was slit before nematode infection. Mortality of engorged I. scapularis females infected by S. carpocapsae was greater than uninfected controls, but did not vary significantly with nematode concentration (50-3,000 infective juveniles per 5-cm-diameter petri dish). The LC50 was 347.8 infective juveniles per petri dish (5 ticks per dish). Hatched egg masses of infected ticks weighed less than those of uninfected controls. Mortality of infected ticks was greatest between 20 and 30 degrees C, and was lower at 15 degrees C.

Animals↗
PubMed1994

Comparison in the immunological properties of Borrelia burgdorferi isolates from Ixodes ricinus derived from three endemic areas in Switzerland.

Borrelia burgdorferi isolates were obtained from Ixodes ricinus from three sites in Switzerland. They were examined by SDS-PAGE and immunoblotting. The phenotypes, in respect of three outer surface proteins (Osp), differed between the sites of collection. In site 1, most isolates had an OspA of 31 kDa and an OspB of 34 kDa; in site 2, isolates presenting an OspA of 33 kDa dominated and in site 3, the isolates with an OspA of 32 kDa and an OspB of 35 kDa were most frequent. This distribution differed significantly. About half of the isolates from sites 1 and 3 reacted with anti-OspA monoclonal antibody H5332 compared to 29% from site 2. Site 1 isolates reacted significantly more frequently (81%) with another anti-OspA monoclonal antibody LA-31 than isolates from site 3 (P < 0.0001). These findings have implications for the epidemiology of Lyme borreliosis, for the further development of serodiagnostic reagents and for the development of a vaccine.

Animals↗
PubMed1994

Infection of field-collected Ixodes ricinus (Acari: Ixodidae) larvae with Borrelia burgdorferi in Switzerland.

Free-living larvae from natural areas in five regions in Switzerland were collected to determine the infection rate of Ixodes ricinus L. larvae by Borrelia burgdorferi Johnson. Larvae were examined for the spirochetes using direct fluorescent antibody assay. Of 652 larvae examined, spirochetes were detected in 20 (3.1%). No differences in infection rate among sites were detected. The low prevalence of B. burgdorferi in larvae, compared with higher infection rate in nymphs (12.8%) and adults (14.5%), suggests that transovarial transmission is inefficient. These results suggest that I. ricinus can serve as a reservoir for B. burgdorferi in nature. Further study is needed on the relative importance of ticks, compared with mammals and birds, as reservoirs for B. burgdorferi.

Animals↗