Search PubMed⌕ Search

Biomedical subjects

R Mischke

Publications and source records attributed to R Mischke.

At least 19 recordsLinked to original sources
PubMed2006

Changes in C-reactive protein and haptoglobin in dogs with lymphatic neoplasia.

Acute phase proteins (APP) are regarded as a useful diagnostic tool in humans with lymphomas, leukaemias and multiple myeloma. C-reactive protein (CRP) and haptoglobin concentrations were measured in dogs with malignant multicentric (high grade) lymphoma (n=16), acute lymphoblastic leukaemia (ALL) (n=11), chronic lymphocytic leukaemia (CLL) (n=7) and multiple myeloma (n=8). Twenty-five healthy dogs served as controls. Measurements of the CRP plasma concentration were performed using a commercial ELISA and haptoglobin was measured with an assay based on its haemoglobin binding capacity. Global group comparisons using Kruskal-Wallis-test revealed significant group differences for both APPs (P<0.0001). Median CRP concentrations were increased in all groups with neoplastic lymphatic disorders (lymphoma: 37.2mg/L, ALL: 47.8mg/L, CLL: 35.5mg/L, myeloma: 17.6mg/L) compared to controls (1.67mg/L; P<0.001). Compared to the healthy controls (median=0.59g/L), haptoglobin was especially increased in dogs with ALL (6.8g/L, P<0.0001) followed by dogs with malignant lymphoma (3.8g/L, P<0.0001), CLL (3.2g/L, P=0.0008), and multiple myeloma (3.0g/L, P=0.0163). For both APPs, a wide range of values was found in all patient groups. The results indicate that particularly severe and acute lymphatic neoplasia, such as high grade lymphoma and ALL, cause significant acute phase reactions in dogs and must be included in the differential diagnoses of increased blood levels of these APPs.

Animals↗
PubMed2006

Evaluation of a standard immunofluorescence assay and a new flow cytometric method for the detection of autoreactive antibodies in dogs with tumours.

The major purpose of the presented study was to develop and to evaluate a flow cytometry-based assay (IIFC) for the determination of autoreactive antibodies in sera from canine cancer patients. A blinded study demonstrated the poor reproducibility of the standard, slide-based and microscopically evaluated indirect immunofluorescence test (IIF), especially with sera displaying a cytoplasmic reactivity. In the IIFC, the intra assay coefficient of variance ranged between 5% and 11%, the inter assay variance between 8% and 25%. The IIFC resulted in significantly less positive results among canine cancer patients (16%) than the IIF (40%). The latter results were due to low titered sera indicating that the standard assay may lead to a high proportion of false positive results. The limitation of the IIFC is that no conclusions can be made about the sub cellular localization of the fluorescence. However, this cytometry-based assay makes a more objective and standardized detection of canine autoreactive antibodies possible.

Animals↗
PubMed2005

Immunocytochemical differentiation of neoplastic and hyperplastic canine epithelial lesions in cytologic imprint preparations.

The aim of the study was to test the potential use of commercially available antibodies generated against human cytokeratins in differentiating canine epithelial tumours in cytological samples. Immunocytochemical staining procedures were performed on 183 different primary epithelial canine tissues (including hyperplasia [n=7], dysplasia [n=3], benign [n=54] and malignant [n=119] neoplasia) and 20 distant metastases of 13 of the malignant tumours. All epithelial tumours and their metastases stained distinctly positive with broad spectrum anti-cytokeratin AE1/AE3. Immunocytological reactions with broad spectrum anti-cytokeratin KL1 produced less reliable results. Numerous negative reactions were found, especially in columnar epithelium tumours, whereas squamous epithelium tumours were KL1-positive. In most cases specific antibodies CK7, CK8,CK14,CK18 and CK20 showed similar reaction patterns when compared to reactivity in human tissues. Immunocytological staining was found to be a reliable and valuable diagnostic technique when combined with conventional cytology and may be especially suitable for the differentiation of undifferentiated epithelial tumours and distant metastases of unknown origin.

Animals↗
PubMed2005

Detection of fibrin generation alterations in dogs with haemangiosarcoma using resonance thrombography.

OBJECTIVE: The objective of the study was to examine the alterations of fibrin generation in dogs with haemangiosarcoma using resonance thrombography. The second objective was to evaluate the sensitivity of this method for the detection of hypofibrinogenaemia and/or increased fibrin(ogen) degradation product (FDP) concentration. ANIMALS, METHODS: Resonance thrombogram (RTG) measurements with two different instruments were performed in 30 unselected dogs with haemangiosarcoma, 14 of which had decreased fibrinogen and 28 of which had an increased FDP concentration (p<0.0001). RESULTS: The RTG-reaction time was less sensitive than the fibrin formation time (RTG-f) and fibrin amplitude (RTG-F). The RTG-f and RTG-F indicated reliably a decrease in fibrinogen concentration (sensitivity: 0.93). The sensitivity of detection of increased FDP levels was considerably higher than that of thrombin time. However, false-negative results were found even at FDP concentrations > or =120 mg/l, especially in cases with high fibrinogen level. Both machines showed similar sensitivity. CONCLUSIONS: The results of this study indicate that canine haemangiosarcoma is frequently associated with severe alterations of fibrin generation due to low fibrinogen and high FDP levels leading to distinct RTG abnormalities. The global test RTG reacts sensitively to a decreased fibrinogen level whereas its accuracy to detect FDP concentrations occurring under pathophysiological conditions is limited. A significant alteration of fibrin generation induced by FDPs may not occur until the serum FDP concentration exceeds 60 mg/l.

Animals↗
PubMed2005

Acute haemostatic changes in accidentally traumatised dogs.

Alterations of the haemostatic system were studied in 30 dogs within 24 h following natural injury. No other exclusion criteria were considered. Most dogs had bone fractures, thoracic and/or abdominal trauma. Compared to the controls, the platelet count and activities of all individual coagulation factors, inhibitors of the blood coagulation system (antithrombin, protein C) and plasminogen were significantly decreased (P < 0.01). The only exceptions were alpha2-plasmin inhibitor activity, which did not differ from the control group (P > 0.05), and an increased fibrinogen concentration (P = 0.0113). Deficiencies in the coagulation system were reflected by frequent abnormal results of the screening tests. In most of the animals, the concentrations of soluble fibrin and/or fibrin(ogen) degradation products were above the reference values (P < 0.0001). The absence of a decrease in fibrinogen and alpha2-plasmin inhibitor reflects their role as acute phase reactants. The results of this study indicate the high frequency of decompensated consumption of haemostatic components in acutely traumatised dogs.

Animals↗
PubMed2005

Incidence of post-anaesthetic arrhythmias in dogs.

OBJECTIVES: To assess the use of Holter monitoring for evaluating the incidence of post-anaesthetic cardiac arrhythmias and associated anaesthetic risk for two different anaesthetic protocols. METHODS: Patients undergoing orthopaedic surgery were randomly divided into two groups with different anaesthetic regimens (group A, isoflurane n = 30; group B, propofol n = 30). Two 24-hour Holter recordings were performed for each patient: the first directly following anaesthesia and the second, as a comparison, on the fifth postoperative day. RESULTS: Although all dogs were healthy on pre-anaesthetic cardiac evaluation, 56 dogs showed arrhythmias in the two 24-hour (Holter) electrocardiograms performed. However, the number of arrhythmias recorded was low in most cases (less than 10 supraventricular extrasystoles and less than 100 ventricular extrasystoles). One patient in group A showed 94 supraventricular extrasystoles during the second monitoring period. Three patients in each group developed more than 100 ventricular extrasystoles during both Holter recordings. There were no statistically significant differences between the two anaesthetic regimens or between the two recordings in both groups. CLINICAL SIGNIFICANCE: The two anaesthetic protocols investigated in this study did not induce an increased incidence of severe arrhythmias in healthy dogs in the post-anaesthetic phase.

Anesthetics, Inhalation↗
PubMed2005

Recurrent bilateral exophthalmos associated with metastatic thymic carcinoma in a pet rabbit.

A five-year-old, castrated, male chinchilla rabbit was presented for evaluation of recurrent bilateral exophthalmos. Besides a transient and stress-related exophthalmos with protrusion of both third eyelids, the ophthalmological examination was unremarkable. Plain radiography of the thorax revealed a large precardial mass of soft tissue density. Cytological preparations from the thoracic mass were dominated by small, mature lymphocytes with approximately 10 to 20 per cent lymphoblasts. Computed tomography of the head showed a symmetrical laterodorsal deviation of both eyes without evidence of retrobulbar masses. On necropsy a large cystic mass was present in the cranial thorax associated with severe hydrothorax, hydropericardium and ascites. Histology identified the precardial mass as thymic carcinoma with metastases in the kidneys. This case illustrates the difficulty of diagnosing thymic tumours based on cytological or histological features of the primary tumour alone. To the authors' knowledge, this is the first case of recurrent bilateral exophthalmos associated with a metastatic thymic carcinoma in a pet rabbit.

Animals↗
PubMed2004

Sensitivity of commercial prothrombin time reagents to detect coagulation factor deficiencies in equine plasma.

The sensitivity of commercial prothrombin time (PT) tests was assessed based on a dilution series of equine pooled plasma (EPP) (experiment 1) and on 40 equine plasma samples with reduced activity of coagulation factors II, V, VII and X (experiment 2). Two different PT reagents (reagent 1, human placental thromboplastin; reagent 2, recombinant human tissue factor) were used according to the manufacturers' instructions (standard test, PT([ST])) and compared to a modified test procedure (modified test, PT([MT])) using sample dilution and fibrinogen addition. In all samples, sensitivity was lower (P<0.01) when using PT([ST]) with reagent 2 (0.20) than when using either PT([ST]) with reagent 1 (0.65) or PT([MT]) with both reagents (reagent 1, 0.60-0.75, reagent 2, 0.58-0.70, depending on sample dilution). The highest sensitivity was found for PT([MT]) when using a 1:20 sample dilution. In those samples in which at least one coagulation factor activity was decreased (by 20%; n=18), the sensitivity of PT([ST]) with reagent 2 (0.33) was found to be inadequate, in contrast to all other test procedures (0.83-0.94). This low sensitivity corresponded to shorter time intervals between different coagulation activity levels prepared by EPP dilution. The results indicate that adequate sensitivity of PT measurements in equine plasma can be achieved using a standard test procedure as long as a suitable reagent is used.

Animals↗
PubMed2004

Studies on platelet aggregation using the Born method in normal and uraemic dogs.

Using the Born method, based on light transmission in platelet rich plasma, the minimum effective concentration (threshold values) of several platelet agonists for inducing maximum platelet aggregation was determined in healthy dogs. The final concentrations of aggregation agonists were as follows: adenosine diphosphate (ADP) (0.5-50 micromol/L; n = 75 healthy dogs), collagen (0.5-20 mg/mL; n = 75), thrombin (0.1-5 IU/mL; n = 75), ristocetin (1-10 mg/mL; n = 10), and epinephrine (5-50 micromol/L; n = 10). Reference values for maximum aggregation with a lower limit of > 80% were achieved for agonist concentrations 25 micromol/L ADP (80-98%), > or = 10 microg/mL collagen (80-96%), and > or = 1 IU/mL thrombin (80-97%). None of the concentrations of epinephrine and ristocetin used in this study induced quantitative aggregation in the whole group of healthy dogs. We also studied platelet aggregation in 14 uraemic dogs using selected concentrations of aggregation agonists. Aggregation was significantly decreased in uraemic dogs using intermediate agonist concentrations, i.e., in the region of the threshold concentration. In contrast, maximum aggregation was increased in uraemic patients compared to reference values using low concentrations of all three agonists (ADP: 1 micromol/L, collagen: 1 microg/mL, and thrombin: 0.1, 0.2 IU/mL).

Adenosine Diphosphate↗
PubMed2003

Influence of platelet count, acetylsalicylic acid, von Willebrand's disease, coagulopathies, and haematocrit on results obtained using a platelet function analyser in dogs.

The platelet function analyser PFA-100 aspirates blood in vitro from a sample reservoir in disposable test cartridges through a microscopic aperture cut into a biologically active membrane at the end of a capillary. In different cartridges the membrane is coated with collagen and adenosine diphosphate (ADP) or collagen and epinephrine (adrenaline) inducing a platelet plug and closure of the aperture. The closure time and total volume of blood flow through the capillary until closure of its aperture were measured. The correlation between platelet count in samples of thrombocytopenic dogs and results of the collagen/ADP cartridge (closure time: r(S)=-0.579; total volume: r(S)=-0.549) was closer than between platelet count and capillary bleeding time. No significant correlation was observed between platelet count and the results obtained with the collagen/epinephrine cartridge. In addition, a higher sensitivity was obtained for the collagen/ADP cartridge. Injection of acetylsalicylic acid into healthy dogs significantly increased closure time and total volume of both types of cartridges (P<0.01). Two dogs with von Willebrand's disease had abnormal values. In contrast, coagulopathies did not significantly influence the results of the platelet function analyser (P>0.05). Despite adequate sensitivity of measurements using the collagen/ADP cartridge to assess quantitative and qualitative platelet disorders in dogs, the influence of haematocrit (P<0.0001) will limit the clinical application of the analyser.

Animals↗
PubMed2003

Sensitivity of different prothrombin time assays to factor VII deficiency in canine plasma.

The factor VII sensitivity of prothrombin time (PT) in dogs was tested using five different PT reagents and a commercial PT variant. The five PT reagents were used according to manufacturers' instructions (standard test, PT([ST])) and also using a modified test instruction (modified test, PT([MT])). Plasma samples with defined factor VII levels (10-100%) were prepared by adding increasing quantities of canine factor VII deficient plasma to the pooled plasma of healthy dogs. Statistical comparison based on prothrombin time ratios (PTR = PT sample: PT measured for 100% factor VII activity level) revealed significant differences between different reagents for PT([ST]) and also for PT([MT]). Factor VII activity at which PT was prolonged to the upper limit of the reference values (FVII([X(0.975)])) was 16-39% (PT([ST])) and 23-35% (PT([MT])). Factor VII sensitivity measured by PTR and also by FVII([X(0.975)]) values, was higher in four of five PT reagents using PT([MT]) when compared with PT([ST]). The results of this study indicate the importance of selecting a sensitive reagent and method for PT measurement and for careful interpretation of PT test results using canine plasma.

Animals↗
PubMed2003

Response of dogs to short-term infusions of carbohydrate- or lipid-based parenteral nutrition.

Parenteral nutrition (PN) is used to support intensive care patients. The risk for adverse metabolic effects depends on the composition of infused solutions and the duration of application. The present study in dogs compares metabolic and endocrine effects of two infusion solutions, with either triglycerides or glucose being the major energy sources, administered in a comparatively short infusion period (10 h/day). PN was administered for 9 days to two groups of five adult dogs to meet energy maintenance requirements. In group PN-LIP 61% of the total energy was derived from lipids and 22% from carbohydrates, compared with 21 and 62% in group PN-GLUC. Among routine haematology and clinical chemistry the plasma levels of glucose, triglycerides, insulin, insulin-like growth factor-I (IGF-I), glucagon, 3,5,3'-triiodothyronine and thyroxin were measured in non-infused dogs and at 2, 4, 6, and 8 h after the start of infusion at days 2 and 8 of the study. Infusions protocols did not cause gross metabolic aberrations. During the actual infusions glucose, triglyceride and insulin concentrations were elevated, each depending on the infusion solution. Concentrations of IGF-I, glucagon, 3,5,3'-triiodothyronine, thyroxin and cortisol did not change significantly. In conclusion short infusion periods of 10 h per day were tolerated by healthy dogs without adverse signs, which could improve practicability of PN also in clinical cases.

Animals↗
PubMed2003

Immunocytological confirmation of bone marrow metastases in a dog with cholangiocarcinoma.

The case history of a four-year-old, male Bernese mountain dog is presented. Carcinoma cells were detected in the liver by ultrasound-guided fine-needle aspiration. Bone marrow aspirated from the iliac crest and the left femur showed a distinct infiltration by carcinoma cells. Immunocytological examination of the liver and bone marrow metastases showed a negative staining result for large spectrum cytokeratin (CK) KL1, a strong positive result for CK7 and a focal weak positive result for CK20. The dog was euthanased due to the grave prognosis. Histopathological examination revealed metastatic cholangiocarcinoma. The authors conclude that cytological and immunocytological examination of bone marrow aspirates should be used more frequently for the detection of distant metastases of carcinomas in small animal medicine.

Animals↗
PubMed2003

The ex-vivo-shunt-model: novel approach for assessing the thrombogenicity of vascular implants.

OBJECTIVE: Disadvantages associated with commercially available vascular implants necessitate alternative strategies to develop new vascular prostheses. Although many tissue characterizing strategies have been defined, no valid test for thrombogenicity exists. Here we introduce a novel concept for thrombogenicity testing of vascular implants METHODS: Silastic tubes were implanted into the carotid arteries of 12 sheep. After placing these shunts, tc99m-labeled platelets were administered and test-vessels were put in between the shunts. Native autologous (n=6), as well as native/acellularized allogeneic (n=6/n=6), and xenogeneic (n=6/n=6) carotid arteries and allogeneic (n=6/n=6) and xenogeneic (n=6/n=6) carotid arteries reseeded with allogeneic endothelial-cells, fibroblasts and myocytes were evaluated. Number and time course of intra-operatively deposited platelets were evaluated with a Geiger-counter; certain areas of platelet deposition located, envisioned and characterized by a gamma-camera and scanning electron-microscopy afterwards. RESULTS: Counter results revealed no significant different platelet depositions when comparing silastic tubes with either autologous or allogeneic native carotid arteries. However, starting 5 minutes after placement, acellularized/reseeded allogeneic (p=0.001/p=0.00004), and xenogeneic (p=0.0001/p=0.01) carotid arteries showed significantly more platelet depositions than native autologous carotides. Moreover, it was possible to show that almost no platelets adhere to native vessels or silastic tubes, thus proving the test method itself. CONCLUSION: The Ex-Vivo-Shunt-Model is a valid method to measure and envision the intrinsic thrombogenicity of vascular implants.

Anastomosis, Surgical↗
PubMed2003

[Comparison of the influence of different anesthetic protocols in the development of post-anesthetic arrhythmia in the dog].

Post-anesthetic holter monitoring was performed in 2 patient groups in order to compare the incidence of cardiac arrhythmias as a result of different anesthetic protocols. The 2 groups differed in their anesthetic protocol. Both groups received levomethadone as pre-anesthetic. The dogs in group A (n = 30) additionally received diazepam, the dogs in group B (n = 30) received propofol instead. Anesthesia was maintained by isoflurane in group A and a propofol constant rate infusion in group B. In each patient 2 holter monitorings were performed. The first recording began directly after anesthesia. As a comparison a second recording was performed on the 5th post-operative day. The recorded number of arrhythmias was low and no statistical difference was demonstrated between the 2 patient groups.

Anesthetics, Intravenous↗
PubMed2002

Commercial variants of the prothrombin time test as a screening test of acquired coagulation factor II, VII, and X deficiencies in dogs.

The aim of this study was to acquire the single factor sensitivity of three commercial variants of the prothrombin time test (PT(Va1)-Thrombotest, PT(Va2)-Normotest, PT(Va3)-Hepato Quick) for canine plasma. For this purpose, 38 samples from animals with coumarin intoxication followed by vitamin K(1) treatment who had a reduced activity of the coagulation factors II, VII, and/or X (experiment 1) as well as 25 plasma samples from animals with moderately reduced activity of the coagulation factors II, V, VII, and/or X caused by a hepatogenic synthesis disorder or disseminated intravascular coagulation (experiment 2), were examined. Measurements for all tests were performed according to the instructions of the manufacturer and also with higher plasma dilution. Furthermore, control measurements were performed with the conventional prothrombin time test (standard test; PT(ST)). The prothrombin time measured with the PT(Va3), which was prolonged in all samples from experiments 1 and 2, especially reflected with high sensitivity the reduced activity of the coagulation factors. The measurements with PT(Va2) and PT(Va1) showed only an insignificantly lower sensitivity (> or =0.88) with a maximum of 1 (experiment 1) and 3 (experiment 2) false negative test results, respectively. Compared to the already high sensitivity, a higher dilution of the sample material did not lead to a significantly higher sensitivity (P>0.05) for any of the tested commercial variants of the prothrombin time assay. While there was no significant difference (P>0.05) between the number of false negative test results in the variants of the prothrombin time assay, in both experiments a significantly higher number of false negative test results was found for the PT(ST) (P<0.001). The results show that, in contrast to the PT(ST), all three tested commercial prothrombin time variants are suitable for the detection of deficiencies of coagulation factors II, VII, and X in canine plasma.

Animals↗
PubMed2002

Blood plasma concentrations of oestradiol-17beta, testosterone and testosterone/oestradiol ratio in dogs with neoplastic and degenerative testicular diseases.

Oestradiol-17beta and testosterone blood plasma concentrations were measured in dogs with Leydig-cell tumours (n=20), Sertoli-cell tumours (n=6), seminomas (n=9), unilateral inguinal cryptorchidism (n=7), abdominal cryptorchidism (n=9, one bilateral), degenerate scrotal testicles (n=6, two bilateral), and animals with normal scrotal testicles (n=20). The testosterone/oestradiol ratio (testosterone concentration [ng/mL]x100/oestradiol concentration [pg/mL]) was calculated.A considerably higher oestradiol concentration was found in dogs with Sertoli-cell tumours (29.0, 14.4-48.3 pg/mL; median, minimum-maximum; P=0.0256, Mann-Whitney test) and lower oestradiol levels were found in animals with seminomas (12.0, 3.4-17.6 pg/mL; P=0.0025) compared to the healthy control group (18.0, 8.6-31.5 pg/mL). Testosterone concentration was decreased in dogs with Sertoli-cell tumours (0.08, 0.03-0.77 ng/mL) when compared to the control group (1.95, 0.05-3.70 ng/mL; P=0.0012). Testosterone/oestradiol ratios differed from the control (9.6, 0.58-35.8) only in dogs with Sertoli-cell tumours (0.32, 0.06-2.80; P=0.0005). Clinical signs of feminization were observed in five dogs with Sertoli-cell tumour and one dog with a Leydig-cell tumour, and were more often associated with decreased testosterone/oestradiol ratios than with an increased oestradiol-17beta concentration.

Animals↗