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Biomedical subjects

H Lutz

Publications and source records attributed to H Lutz.

At least 19 recordsLinked to original sources
PubMed2007

Genotyping of Babesia bigemina from cattle from a non-endemic area (Switzerland).

In August 2002, bovine anaplasmosis and concurrent infections with Mycoplasma sp. and piroplasms were reported in a cattle herd in an alpine region of Switzerland. The piroplasms were identified by PCR/sequencing of part of the 18S rRNA gene as Babesia bigemina and Theileria of the buffeli/sergenti/orientalis-complex, which have never been diagnosed in Switzerland before. The B. bigemina isolate was genetically characterised at two loci and compared with isolates from Italy, Spain, Turkey, Kenya and Mexico. Analysis of the internal transcribed spacer 2 (ITS2) of the rRNA genes revealed high polymorphism not only among the isolates but even within the isolates, and the presence of two types of the ITS2 in every isolate was confirmed. A dendrogram based on ITS2 sequences showed that the Swiss isolate was most closely related to a Spanish isolate but no sequences of the isolate from Switzerland were identical to any of the other isolates. The isolate from Italy was not positioned in the same cluster as the Swiss and the Spanish isolate. This had been anticipated as the nearest known endemic area of B. bigemina in Central Italy. Sequence analysis of the rhoptry-associated protein-1c gene (rap1c) confirmed the similarity of the Swiss and Spanish isolate. Hence, our molecular analyses of the Swiss B. bigemina isolate did not unequivocally track its geographical origin and the way of introduction remains obscure.

Animals↗
PubMed2006

Effects of two diets on the haematology, plasma chemistry and intestinal flora of budgerigars (Melopsittacus undulatus).

Two groups of 22 budgerigars (Melopsittacus undulatus) were housed for 12 months under identical conditions. One group was fed a commercial seed mixture plus carrots and a mineral supplement, and the other group was fed a commercially formulated diet plus carrots. Samples of blood and faeces were collected initially and after three, six, nine and 12 months. There were no significant differences between the haematological values of the two groups. The group fed the seed mixture had significantly higher concentrations of glucose, albumin, triglycerides and uric acid, and higher activity of aspartate aminotransferase, but the values were within the published reference ranges for normal birds. There were no significant differences between the faecal samples from the two groups, except that the fungus Macrorhabdus ornithogaster was identified in 48.3 per cent of the samples from the group fed the commercially formulated diet but from only 3.4 per cent of the samples from the group fed the seed mixture.

Animal Feed↗
PubMed2006

Detection of feline leukemia virus RNA in saliva from naturally infected cats and correlation of PCR results with those of current diagnostic methods.

A novel diagnostic test for feline leukemia virus (FeLV) RNA in saliva from naturally infected cats is described in this study. We evaluated different diagnostic tests and compared them with the widely used enzyme-linked immunosorbent assay (ELISA) for the detection of p27 in the diagnosis of FeLV. Blood samples from 445 cats were tested for the presence of provirus by real-time PCR and plasma and saliva specimens from those cats were tested for the presence of viral RNA by real-time reverse transcription (RT)-PCR and for the presence of p27 by ELISA. In comparison to conventional ELISA, the diagnostic sensitivity and specificity of the detection of salivary FeLV RNA by real-time RT-PCR were found to be 98.1 and 99.2%, respectively. Detection of viral RNA in saliva had a positive predictive value of 94.6% and a negative predictive value of 99.7%. The kappa value was 0.96, demonstrating an almost perfect agreement between both tests. Furthermore, we confirmed previous results showing that a number of cats which tested negative for the presence of p27 in plasma were in fact positive for the presence of DNA provirus in blood specimens (5.4%). However, 96.4% of these latently infected cats did not shed viral RNA in saliva; therefore, we assume that these cats are of relatively low clinical importance at the time of testing. This study shows considerable diagnostic value of the detection of saliva FeLV RNA in naturally infected cats. This new diagnostic method has advantages over the conventional ELISA, such as less invasive sample collection and no requirement for trained personnel.

Animals↗
PubMed2005

Shedding of feline leukemia virus RNA in saliva is a consistent feature in viremic cats.

The purpose of this investigation was to characterize the shedding pattern of feline leukemia virus (FeLV) RNA in saliva, and to correlate it with the proviral load in whole blood, viral load in plasma, levels of p27 in saliva and plasma, the isolation of infectious FeLV from saliva, and the titers of FeLV-specific antibodies of the IgG and IgA isotypes. We evaluated 24 experimentally FeLV-infected cats for these parameters using real-time RT-PCR and PCR, cell culture assay and sandwich ELISA. We observed that shedding of viral RNA in saliva was a consistent feature in viremic cats. Latently FeLV-infected cats, displaying a very low proviral load, did not shed infectious virus in saliva, but occasionally shed viral RNA. Consequently, salivary shedding of FeLV RNA may not necessarily indicate a transmission potential for susceptible cats. This study also confirmed previous results from our laboratory, showing that a negative result for p27 in plasma, or for viral RNA in plasma or saliva does not exclude FeLV infection, considering that blood cells from those cats contained provirus. We also showed that FeLV RNA and DNA were stable for more than 64 days in saliva samples stored at room temperature. We conclude that the detection of FeLV RNA in saliva may be a useful indicator of viremia, and that the detection of salivary viral RNA by RT-PCR could become a reliable tool for the diagnosis of FeLV infection, which is facilitated by the low invasive method of collection of the samples.

Animals↗
PubMed2005

Factors associated with upper respiratory tract disease caused by feline herpesvirus, feline calicivirus, Chlamydophila felis and Bordetella bronchiseptica in cats: experience from 218 European catteries.

A full history of the management practices and the prevalence of upper respiratory tract disease (URTD) at 218 rescue shelters, breeding establishments and private households with five or more cats was recorded. Oropharyngeal and conjunctival swabs and blood samples were taken from 1748 cats. The prevalences of feline herpesvirus (FHV), feline calicivirus (FCV), Chlamydophila felis and Bordetella bronchiseptica were determined by PCR on swab samples. An ELISA was applied to determine the prevalence of antibodies to B. bronchiseptica. The rates of detection by PCR of each pathogen in the cats in catteries with and without ongoing URTD were, respectively, FHV 16 per cent and 8 per cent; FCV 47 per cent and 29 per cent; C. felis 10 per cent and 3 per cent; and B. bronchiseptica 5 per cent and 1.3 per cent; the seroprevalences of B. bronchiseptica were 61 per cent and 41 per cent, respectively. There was evidence that FHV, FCV and B. bronchiseptica played a role in URTD. The risk factors associated with the disease were less than excellent hygiene, contact with dogs with URTD, and larger numbers of cats in the cattery or household.

Animals↗
PubMed2005

Age-related dynamics of constitutive cytokine transcription levels of feline monocytes.

Monocytes/macrophages are central mediators of inflammation and immunity and therefore of major interest in the study of immunosenescence. In healthy adult cats, monocytes have been shown to constitutively transcribe pro- and anti-inflammatory cytokines. However, in order to characterize the effect of age, feline monocyte functions were examined for changes in cytokine transcription levels in early stages of immunosenescence. For this purpose, isolated, short-term cultured monocytes from barrier-maintained adult cats of different ages (15 mo to 10 yr) were examined for transcription of IL-1 beta, IL-6, IL-10, IL-12 p40 and TNF-alpha by real-time PCR. Transcription levels of cytokines varied and were generally highest for IL-1 beta. For IL-1 beta, IL-6 and IL-12 p40, both young and old cats exhibited highest levels. The age association was significant. TNF-alpha appeared to be transcribed at similar levels over the examination period, whereas IL-10 tended to decline with age but without any statistical significant differences. The observed age association of the constitutive transcription of some cytokines indicates a drop in monocyte activities from youth to middle age, which is then followed by a (progressive) increase with increasing age. This provides evidence that monocytes are in part responsible for the pro-inflammatory status observed with ageing.

Aging↗
PubMed2005

Anaplasma phagocytophilum infection in a dog: identifying the causative agent using PCR.

A diagnosis of Anaplasma phagocytophilum infection was confirmed in a two-year-old male golden retriever displaying few clinical and haematological abnormalities. This was achieved by demonstrating ehrlichial organisms in circulating neutrophils, by indirect immunofluorescence assay using A phagocytophilum as an antigen, and by detecting DNA specific for the 16S rRNA gene of granulocytic Anaplasma by PCR. After treatment with doxycycline for 10 days the dog showed improvement and the laboratory values returned to normal.

Anaplasma phagocytophilum↗
PubMed2005

Serologic cross-reactivity between Anaplasma marginale and Anaplasma phagocytophilum.

In the context of a serosurvey conducted on the Anaplasma marginale prevalence in Swiss cattle, we suspected that a serological cross-reactivity between A. marginale and A. phagocytophilum might exist. In the present study we demonstrate that cattle, sheep and horses experimentally infected with A. phagocytophilum not only develop antibodies to A. phagocytophilum (detected by immunofluorescent-antibody assay) but also to A. marginale (detected by a competitive enzyme-linked immunosorbent assay). Conversely, calves experimentally infected with A. marginale also developed antibodies to A. phagocytophilum using the same serological tests. The identity of 63% determined in silico within a 209-amino-acid sequence of major surface protein 5 of an isolate of A. marginale and one of A. phagocytophilum supported the observed immunological cross-reactivity. These observations have important consequences for the serotesting of both, A. marginale and A. phagocytophilum infection of several animal species. In view of these new findings, tests that have been considered specific for either infection must be interpreted carefully.

Anaplasma marginale↗
PubMed2004

High viral loads despite absence of clinical and pathological findings in cats experimentally infected with feline coronavirus (FCoV) type I and in naturally FCoV-infected cats.

Specified pathogen-free cats were naturally infected with FCoV or experimentally infected with FCoV type I. Seroconversion was determined and the course of infection was monitored by measuring the FCoV loads in faeces, whole blood, plasma and/or monocytes. Tissue samples collected at necropsy were examined for viral load and histopathological changes. Experimentally infected animals started shedding virus as soon as 2 days after infection. They generally displayed the highest viral loads in colon, ileum and mesenteric lymph nodes. Seroconversion occurred 3-4 weeks post infection. Naturally infected cats were positive for FCoV antibodies and monocyte-associated FCoV viraemia prior to death. At necropsy, most animals tested positive for viral shedding and FCoV RNA was found in spleen, mesenteric lymph nodes and bone marrow. Both experimentally and naturally infected cats remained clinically healthy. Pathological findings were restricted to generalized lymphatic hyperplasia. These findings demonstrate the presence of systemic FCoV infection with high viral loads in the absence of clinical and pathological signs.

Animals↗
PubMed2004

Reduced constitutive cytokine transcription in isolated monocytes of clinically healthy cats, infected with an FIV strain of low pathogenicity.

Twenty-five barrier-maintained cats had been experimentally infected for 9.5 months with an FIV strain of low pathogenicity, FIV Zurich 2. Animals were clinically healthy and did not exhibit any haematological changes. FIV proviral DNA was demonstrated in peripheral blood lymphocytes of all cats and in monocytes of most animals, identifying FIV Zurich 2 as a both lympho- and monocytotropic strain. Monocytes were isolated from FIV-infected cats as well as from age-matched uninfected control cats, short-term cultured and examined for cytokine (IL-1beta, IL-6, IL-10, IL-12 p40 and TNF-alpha) transcription by real-time PCR. Constitutive transcription of cytokines in monocytes from FIV-infected cats was restricted to IL-1beta and, in the majority of samples, TNF-alpha. For all cytokines, transcription levels were significantly lower in FIV-infected cats than in control cats. Transcription was often least intense in those samples where FIV infection of the monocyte fraction was not demonstrated. Results show that infection of cats with an FIV strain of low pathogenicity was associated with depression of constitutive cytokine transcription in monocytes even if clinical and haematological changes were not observed.

Animals↗
PubMed2004

[Anaplasmosis in a Swiss dairy farm: an epidemiological outbreak investigation].

In summer of 2002, a case of severe clinical bovine anaplasmosis caused great losses in a dairy farm of an animal trader in Grisons. This article outlines the general approach of an outbreak investigation considering the case of anaplasmosis as an example. The goals of such investigations are to identify and eliminate the source of a disease outbreak in order to avoid additional cases. In addition, recommendations should be developed for preventing or limiting the magnitude of similar outbreaks in the future. In the outbreak presented, the causative agents were probably brought into the dairy farm by animal trade. Due to the large herd size, a missing quarantine for new animals and the coinfection with several pathogens, this case led to a high number of fatalities. The investigations of this outbreak demonstrated the importance of an universal and consistent identification of individual animals for the reconstruction of their movements. The veterinary practitioner should be reminded to act cautiously when facing strange clinical cases and to also consider "exotic diseases" as a possible cause.

Anaplasmosis↗
PubMed2003

A control system approach for evaluating somatosensory activation by laser-Doppler flowmetry in the rat cortex.

Coupling between functional cortical activity and blood flow is a regulatory principle that adjusts the supply of substrates to the metabolic needs of the tissue. The flow response is usually expressed as the maximum increase over baseline; control system analysis allows the description of the entire time course and the main dynamic features of the regulative principle. In chloralose-anesthetized rats, forepaws were stimulated by trains of electric pulses of 0.3 or 5 ms duration. Blood flow was recorded in the contralateral somatosensory cortex by laser-Doppler flowmetry and correlated with the amplitude of primary somatosensory evoked potentials (SEP). Changes were analyzed by a control system approach. Pulses of 0.3 or 5 ms evoked SEPs of similar amplitude, whereas flow responses differed: 0.3 ms pulses led to a peak and plateau characteristic, 5 ms pulses evoked a plateau characteristic. The flow response evoked by 0.3 ms pulses can be modeled mathematically by an initial feedforward regulative principle followed after some delay by feedback controlled flow stabilization, whereas 5 ms pulses lack the feedforward component. The absence of an electrophysiological difference points to a dissociation between electrophysiological and hemodynamic responses and may be of importance for the understanding of flow coupling.

Algorithms↗
PubMed2003

[Fever after a tick bite: clinical manifestations and diagnosis of acute tick bite-associated infections in northeastern Switzerland].

BACKGROUND: Different tick-borne infections can cause an acute febrile illness. The study objectives were to investigate the clinical manifestations and diagnosis of infections among patients who presented with fever after a tick-bite, and to detect newly described pathogens, including Ehrlichia, Babesia and Rickettsia helvetica, in North-Eastern Switzerland. PATIENTS AND METHODS: : We studied 75 patients (41 male, 34 female, median age 38 years, among them 10 children) who had fever within 3 weeks after a tick-bite. Paired sera were tested for antibodies to Borrelia burgdorferi, tick-borne encephalitis virus, Anaplasma (Ehrlichia) phagocytophila, Babesia microti, B. divergens, and Rickettsia helvetica. In addition, microscopy and polymerase chain reaction was used to detect Ehrlichia. Clinical data were obtained at baseline and at 1 and 2 year follow-up. RESULTS: Tick-borne infections were confirmed or possible in 36 (48 %) patients: 7 (9 %) Erythema migrans, 6 (8 %) other specific manifestations of Lyme borreliosis, 6 (8 %) Lyme borreliosis presenting as non-specific febrile illness, 8 (11 %) tick-borne encephalitis, 7 (10 %) granulocytic ehrlichiosis, 1 B. microti infection in a traveler from the US and 6 (8 %) dual infections. In 8 (11 %) patients serological findings were suggesting possible acute or past R. helvetica infection. CONCLUSION: Among patients with fever after a tick-bite, Lyme borreliosis was most frequently found. There was no evidence for babesiosis among the resident population. Serologic data suggest that human granulocytic ehrlichiosis and R. helvetica infections may be endemic in Switzerland. Among 50 % of the patients no tick-borne infections could be diagnosed.

Acute Disease↗
PubMed2002

Up-regulation by feline interleukin-4 and down-regulation by feline interferon-gamma of major histocompatibility complex class II on cat B-lymphocytes.

Interleukin-4 (IL-4) exhibits numerous biological and immunoregulatory functions on B- and T-lymphocytes, monocytes, and dendritic cells in both mice and humans. In the present study, we show that IL-4 also has a regulatory function in the cat species. Cells transfected with IL-4 DNA expressed a biologically active protein as demonstrated by the up-regulation of MHC class II molecules on B-lymphocytes (CD21(+)) in a flow cytometric assay. Increased levels of MHC class II expression on CD21(+) cells were seen in 11 out of 12 cats (p<0.05). In addition, 12 out of 12 cats showed up-regulation of MHC class II on CD21(-) cells, mainly consisting of T-lymphocytes (p<0.05). In contrast, concanavalin A (ConA)-induced culture supernatant from peripheral blood mononuclear cells (PBMCs) containing high levels of interferon-gamma (IFN-gamma) transcripts induced down-regulation of MHC class II molecules on CD21(+) cells of all samples (p<0.05). Variable results were observed for CD21(-) cells incubated with ConA-conditioned medium (p=0.71). The nature of the cytokine(s) responsible for these effects remains to be determined. However, the fact that down-regulation of MHC class II molecules on B cells occurred in all cats tested suggests that IFN-gamma may be involved. These data provide further insight into the mechanism by which MHC class II expression is regulated in feline lymphocytes, and suggest that the Th1/Th2 paradigm is also present in the cat.

Animals↗
PubMed2002

[Reference values in the cerebrospinal fluid of calves between four and eight weeks of age].

Reference values for the following parameters were established in the cerebrospinal fluid of 27 calves between four and eight weeks of age: specific weight, protein concentration, erythrocyte count, total leucocyte count with cell differentiation, creatin kinase activity, glucose and sodium. If possible, the findings were compared with those of other authors in calves and adult bovines. With 24.3 cells per microliter the 90% quantile of the total leucocyte count was seated significantly above comparable values for adult bovines. Hence, in individual cases markedly higher leucocyte counts can be expected in the cerebrospinal fluid of calves. In agreement with other authors, the protein concentration in calves was lower than in adult bovines. The reference range for creatin kinase activity was increased whereas the one for sodium was only slightly increased compared to earlier investigations in calves and in adult bovines.

Animals↗
PubMed2002

[New molecular biology detection methods for tick-borne infectious agents].

Tick-borne zoonotic pathogens are well known in many areas all over the world. Among the tick-borne transmitted diseases in Switzerland, Lyme disease caused by Borrelia burgdorferi, ehrlichiosis caused by various species of Ehrlichia and tick-borne encephalitis caused by the tick-borne encephalitis virus (TBEV) are the most important zoonotic diseases. Early diagnosis and treatment is necessary to prevent fatal infections and chronic damage to various tissues. Due to the variety of uncharacteristic clinical signs, tick-borne diseases are not easily recognized. Diagnosis is based on clinical findings, a record of tick exposure, and direct or indirect detection of the pathogen. Here we discuss briefly the most important tick-borne infections and their diagnosis with emphasis on a new molecular diagnostic tool--the real-time TaqMan PCR--and its importance for the diagnosis of tick-borne pathogens.

Animals↗
PubMed2002

Fatal Hemorrhage following perforation of the aorta by a barb of the Gianturco-Rösch esophageal stent.

Self-expanding metal stents are an established option in the palliative treatment of malignant stenoses of the esophagus. Herein, we report on a 60-year-old man with a recurrent stenosis that developed 2 months after radiochemotherapy for a squamous cell carcinoma in the middle part of the esophagus. To relieve progressive dysphagia, a Gianturco-Rösch stent (Cook-Z stent, 10 cm, PE-covered, manufactured by William Cook Europe) was implanted. Six weeks later, precipitous massive hemoptysis leading to the collapse and death of the patient occurred. Autopsy showed that a barb in the middle of the stent had perforated the aortic arch, resulting in massive bleeding into the gastrointestinal tract, and aspiration. Although hemorrhage and esophageal perforation are known late complications of all types of metal stents, our case is the first description of a perforation involving a fixation barb. These barbs are a particular feature of the European version of the Cook-Z stent, and are intended to prevent stent migration. In future, any hemorrhage observed after stent implantation should prompt a search for perforation by a barb (autopsy!). If necessary, the European version of the Gianturco Z stent should be modified.

Aorta, Thoracic↗