Many migrating birds undertake extraordinary long flights. How birds are able to perform such end... more Many migrating birds undertake extraordinary long flights. How birds are able to perform such endurance flights of over 100-hour durations is still poorly understood. We examined energy expenditure and physiological changes in Northern Bald Ibis Geronticus eremite during natural flights using birds trained to follow an ultra-light aircraft. Because these birds were tame, with foster parents, we were able to bleed them immediately prior to and after each flight. Flight duration was experimentally designed ranging between one and almost four hours continuous flights. Energy expenditure during flight was estimated using doubly-labelled-water while physiological properties were assessed through blood chemistry including plasma metabolites, enzymes, electrolytes, blood gases, and reactive oxygen compounds. Instantaneous energy expenditure decreased with flight duration, and the birds appeared to balance aerobic and anaerobic metabolism, using fat, carbohydrate and protein as fuel. This m...
Vascular endothelial growth factor (VEGF) stimulates endothelial cell proliferation and has a piv... more Vascular endothelial growth factor (VEGF) stimulates endothelial cell proliferation and has a pivotal role in tumour angiogenesis. The expression of VEGF and its receptors VEGFR-1 and VEGFR-2 was examined immunohistochemically in 43 specimens of canine lymphoma and in six normal lymph nodes. Western blotting and reverse transcriptase polymerase chain reaction (RT-PCR) were performed to detect VEGF protein and mRNA, respectively. VEGF protein was expressed by 60% of the tumours with diffuse cytoplasmic labelling of the neoplastic cells. Endothelial cells, macrophages and plasma cells were also immunolabelled. VEGFR-1 was expressed by variable numbers of neoplastic cells in 54% of lymphoma specimens. VEGFR-1 was also expressed by macrophages, plasma cells, reticulum cells, and vascular endothelial cells. Macrophages and lymphocytes in germinal centres of normal lymph nodes were also immunoreactive with anti-VEGF and VEGFR-1. Most tumours did not express VEGFR-2 but in 7% of sections there was focal labelling of neoplastic and endothelial cells, with a cytoplasmic and perinuclear pattern. The observed variability in expression of VEGF and its receptors probably relates to the fact that lymphoma is a heterogenous lymphoproliferative tumour. Individual differences in VEGF and VEGFR expression must be taken into account when VEGF and VEGFR-targeted approaches for anti-angiogenic therapy are considered in dogs.
To describe the effects of long-term treatment with four different eye ointment bases (OBs) in ca... more To describe the effects of long-term treatment with four different eye ointment bases (OBs) in cats. Ten healthy cats. The study was performed in two periods. Four different OBs were tested. Hundred grams of OB contained the following: OB-A: 35.17 g liquid paraffin (lp), 64.83 g white petrolatum (wp); OB-B: 10.03 g lp, 84.95 g wp 5.02 g lanolin; OB-C: 18.34 g lp, 51.40 g wp, 25.00 mg KH2 PO4 , 57.00 mg K2 HPO4 , 18.90 g eucerinum anhydricum, 11.28 g water for injections; and OB-D: 70 g unguentum lanalcoli, 20 g lp, 10 g aqua conservans. One eye was treated, and the other served as a negative control. Cats received the OBs TID for 28 days. The two study periods were separated by a 4-month washout phase. Samples for conjunctival impression cytology, swabs for bacteriologic and mycologic examination, and cytobrush samples for FHV-1 and Chlamydophila felis PCR detection were obtained. Both eyes were examined daily. Severity of ocular symptoms was scored using a modified Draize eye irritation test. A total of five eyes were treated with OB-A, five with OB-B, four with OB-C, and five with OB-D. Treated eyes had significantly higher clinical scores. Eyes receiving OB-A had the highest overall clinical score. The results of bacteriologic and mycologic examination concur with the previously published data. All samples tested were negative for FHV-1 and Chlamydophila felis. There was no significant difference between treated and control eyes upon cytological examination. The application of OBs resulted in clinical symptoms in treated eyes. The long-term use of ointments is not well tolerated in cats and may lead to ocular irritation.
Impression cytology is a noninvasive investigation of the ocular surface. It uses the adhesive fe... more Impression cytology is a noninvasive investigation of the ocular surface. It uses the adhesive features of different filter papers to collect a monolayer of epithelial cells from the cornea and/or conjunctiva. Samples obtained by impression cytology exhibit all characteristics of an ideal cytology specimen. The aim of this study was to test the feasibility of impression cytology and determine the most appropriate filter paper to achieve maximum diagnostic value of the feline eye. Ten healthy cats. The study was conducted in two phases. In the first phase, eight different filter papers (FPs) with various pore sizes were tested: 3.0-, 1.2-, 0.8-, 0.45-, 0.22-, 0.05- and 0.025-μm cellulose acetate papers and a 0.4-μm Biopore membrane (BM). Samples were obtained from the superior bulbar and from the inferior palpebral conjunctiva. In the second phase, three different sampling methods - with and without topical anesthesia, and with topical anesthesia and drying of the conjunctiva - were ...
The health status of a 4-year-old female, dd-haplotype miniature pig deteriorated rapidly, so the... more The health status of a 4-year-old female, dd-haplotype miniature pig deteriorated rapidly, so the animal finally had to be euthanized because of poor clinical condition. Necropsy revealed a massive leukocytic infiltration in the parenchymatous organs of the abdominal cavity. On hematologic cell counting, severe leukocytosis (69.3 x 10(9) cells/liter) and high-grade basophilia (6.9 x 10(9) cells/liter) were evident. Cytologic examination, as well as analysis of expression of leukocyte differentiation antigens by means of flow cytometry, classified blasts, which accounted for about 22% of leukocytes, as biphenotypic cells co-expressing the myeloid marker SWC3 (CD172a) and the lymphoid markers CD5 and CD25. Hematologic features resembled those seen in humans with chronic myeloid leukemia at blast phase.
A 22-month-old, female rabbit was presented with a 1-day history of acute unilateral exophthalmos... more A 22-month-old, female rabbit was presented with a 1-day history of acute unilateral exophthalmos. Ultrasonography and computed tomography (CT) of the orbit revealed an orbital mass. Retrobulbar lymphoma was diagnosed following fine-needle aspiration biopsy (FNAB). Thoracic radiographs were normal, and ultrasonography of the abdomen showed focal hypoechoic thickening of the bowel wall and hypoechoic enlarged lymph nodes. The rabbit was euthanized and histopathology identified the retrobulbar mass as B-cell malignant lymphoma of the Harder's gland. Mesenteric lymph nodes, caecum, and both kidneys were also affected. This is the first documented case of malignant lymphoma of the Harder's gland in a rabbit.
The aim of the study was to investigate if there is a clinically relevant influence of daytime or... more The aim of the study was to investigate if there is a clinically relevant influence of daytime or season and if there are sex-dependant differences in some frequently determined clinical chemistry parameters. The study was performed with 99 1.5- to 2-year old healthy budgerigars of three races. A harmonic regression analysis was performed taking into account linear and cyclic trends over the year. Correlations were investigated by the calculation of Spearman correlation coefficients. Summarizing, it can be said that some circadian, seasonal, as well as sex- and race-dependant influences have been shown. However, although the differences are statistically significant, they were too small to have an impact on clinical decision making. As clinical chemistry results are in practice independent from the influence factors investigated, their meaning and use as a diagnostic tool is further substantiated.
Differentiation between motor and sensory fascicles is frequently necessary in reconstructive per... more Differentiation between motor and sensory fascicles is frequently necessary in reconstructive peripheral nerve surgery. The goal of this experimental study was to verify if centrally motor evoked potentials (MEP) could be implemented to differentiate sensory from motor fascicles, despite the well-known intermingling between nerve fascicles along their course to their distant periphery. This new procedure would enable surgeons to use MEP for placing nerve grafts at corresponding fascicles in the proximal and distal stumps without the need to use time-consuming staining. In ten sheep, both ulnar nerves were exposed at the terminal bifurcation between the last sensory and motor branch. Animals were then relaxed to avoid volume conduction. On central stimulation, the evoked nerve compound action potentials were simultaneously recorded from both terminal branches. In all cases, neurogenic motor nerve action potentials were recorded only from the terminal motor branch. The conclusion was that MEPs can be used for intraoperative differentiation between sensory and motor nerves. Further studies are necessary to develop this method for in situ measurements on intact nerve trunks.
Research in osteoporosis, which is a complex systemic disease, demands suitable large animal mode... more Research in osteoporosis, which is a complex systemic disease, demands suitable large animal models. In pigs, most research has been done in growing minipigs, which probably are not ideal models for postmenopausal osteoporosis. Therefore, our aim was to analyze the effects of ovariectomy (OVX) and nutritive calcium shortage on multiparous Large White sows. 32 animals were randomly assigned to 4 groups in a cross design with OVX vs. sham and physiological calcium supplementation (0.75% calcium) vs. dietary calcium shortage (0.3% calcium). The observation period was 10 months with blood sampling every 2 months for hematological, immunological, and biochemical bone marker measurements. At the termination of the experiment, animals were sacrificed. Samples of trabecular bone of distal radius, proximal tibia, and sixth lumbar vertebra were subjected to micro-computed tomography imaging and ashed afterwards. Dual X-ray absorptiometry scans of the proximal femora were performed with prepared bones being placed in a water bath for mimicking soft tissue. Analyses of bone marker and cytokine profile kinetics, distribution of leukocyte subpopulations, and morphometrical and densitometrical analyses showed no evidence of any impact of OVX or calcium shortage. In conclusion, the skeleton of adult sows of a conventional breed is seemingly protected from effects of OVX and calcium shortage.
This study assessed the influence of driving speed and revolution rate per minute of two reamers ... more This study assessed the influence of driving speed and revolution rate per minute of two reamers on femoral intramedullary pressure increases and fat intravasation. The AO and Howmedica reamers were tested in four groups with different combinations of driving speed and revolution rate per minute in both femurs in a sheep model. The 24 animals were exposed to hemorrhagic shock after midshaft osteotomy and were resuscitated before reaming of both femoral shafts. Controlled reaming was performed at 15 and 50 mm/second driving speed with 150 and 450 revolutions per minute. Fat intravasation and intramedullary pressure were measured by transesophageal echocardiography, Gurd test, and a piezoelectric gauge, respectively. Low driving speed and high revolutions per minute with the smaller cored reamer led to lower intramedullary pressure changes. The same reaming parameters led to greater pulmonary stress during surgery of the second side. Reaming with a smaller cored reamer and modified reaming parameters leads to a lower increase in intramedullary pressure and reduces the amount of fat intravasation. Primary reamed intramedullary nailing should be done after resuscitation at a low driving speed and high revolutions per minute with a smaller cored reamer to minimize the risk of pulmonary dysfunction.
Many migrating birds undertake extraordinary long flights. How birds are able to perform such end... more Many migrating birds undertake extraordinary long flights. How birds are able to perform such endurance flights of over 100-hour durations is still poorly understood. We examined energy expenditure and physiological changes in Northern Bald Ibis Geronticus eremite during natural flights using birds trained to follow an ultra-light aircraft. Because these birds were tame, with foster parents, we were able to bleed them immediately prior to and after each flight. Flight duration was experimentally designed ranging between one and almost four hours continuous flights. Energy expenditure during flight was estimated using doubly-labelled-water while physiological properties were assessed through blood chemistry including plasma metabolites, enzymes, electrolytes, blood gases, and reactive oxygen compounds. Instantaneous energy expenditure decreased with flight duration, and the birds appeared to balance aerobic and anaerobic metabolism, using fat, carbohydrate and protein as fuel. This m...
Vascular endothelial growth factor (VEGF) stimulates endothelial cell proliferation and has a piv... more Vascular endothelial growth factor (VEGF) stimulates endothelial cell proliferation and has a pivotal role in tumour angiogenesis. The expression of VEGF and its receptors VEGFR-1 and VEGFR-2 was examined immunohistochemically in 43 specimens of canine lymphoma and in six normal lymph nodes. Western blotting and reverse transcriptase polymerase chain reaction (RT-PCR) were performed to detect VEGF protein and mRNA, respectively. VEGF protein was expressed by 60% of the tumours with diffuse cytoplasmic labelling of the neoplastic cells. Endothelial cells, macrophages and plasma cells were also immunolabelled. VEGFR-1 was expressed by variable numbers of neoplastic cells in 54% of lymphoma specimens. VEGFR-1 was also expressed by macrophages, plasma cells, reticulum cells, and vascular endothelial cells. Macrophages and lymphocytes in germinal centres of normal lymph nodes were also immunoreactive with anti-VEGF and VEGFR-1. Most tumours did not express VEGFR-2 but in 7% of sections there was focal labelling of neoplastic and endothelial cells, with a cytoplasmic and perinuclear pattern. The observed variability in expression of VEGF and its receptors probably relates to the fact that lymphoma is a heterogenous lymphoproliferative tumour. Individual differences in VEGF and VEGFR expression must be taken into account when VEGF and VEGFR-targeted approaches for anti-angiogenic therapy are considered in dogs.
To describe the effects of long-term treatment with four different eye ointment bases (OBs) in ca... more To describe the effects of long-term treatment with four different eye ointment bases (OBs) in cats. Ten healthy cats. The study was performed in two periods. Four different OBs were tested. Hundred grams of OB contained the following: OB-A: 35.17 g liquid paraffin (lp), 64.83 g white petrolatum (wp); OB-B: 10.03 g lp, 84.95 g wp 5.02 g lanolin; OB-C: 18.34 g lp, 51.40 g wp, 25.00 mg KH2 PO4 , 57.00 mg K2 HPO4 , 18.90 g eucerinum anhydricum, 11.28 g water for injections; and OB-D: 70 g unguentum lanalcoli, 20 g lp, 10 g aqua conservans. One eye was treated, and the other served as a negative control. Cats received the OBs TID for 28 days. The two study periods were separated by a 4-month washout phase. Samples for conjunctival impression cytology, swabs for bacteriologic and mycologic examination, and cytobrush samples for FHV-1 and Chlamydophila felis PCR detection were obtained. Both eyes were examined daily. Severity of ocular symptoms was scored using a modified Draize eye irritation test. A total of five eyes were treated with OB-A, five with OB-B, four with OB-C, and five with OB-D. Treated eyes had significantly higher clinical scores. Eyes receiving OB-A had the highest overall clinical score. The results of bacteriologic and mycologic examination concur with the previously published data. All samples tested were negative for FHV-1 and Chlamydophila felis. There was no significant difference between treated and control eyes upon cytological examination. The application of OBs resulted in clinical symptoms in treated eyes. The long-term use of ointments is not well tolerated in cats and may lead to ocular irritation.
Impression cytology is a noninvasive investigation of the ocular surface. It uses the adhesive fe... more Impression cytology is a noninvasive investigation of the ocular surface. It uses the adhesive features of different filter papers to collect a monolayer of epithelial cells from the cornea and/or conjunctiva. Samples obtained by impression cytology exhibit all characteristics of an ideal cytology specimen. The aim of this study was to test the feasibility of impression cytology and determine the most appropriate filter paper to achieve maximum diagnostic value of the feline eye. Ten healthy cats. The study was conducted in two phases. In the first phase, eight different filter papers (FPs) with various pore sizes were tested: 3.0-, 1.2-, 0.8-, 0.45-, 0.22-, 0.05- and 0.025-μm cellulose acetate papers and a 0.4-μm Biopore membrane (BM). Samples were obtained from the superior bulbar and from the inferior palpebral conjunctiva. In the second phase, three different sampling methods - with and without topical anesthesia, and with topical anesthesia and drying of the conjunctiva - were ...
The health status of a 4-year-old female, dd-haplotype miniature pig deteriorated rapidly, so the... more The health status of a 4-year-old female, dd-haplotype miniature pig deteriorated rapidly, so the animal finally had to be euthanized because of poor clinical condition. Necropsy revealed a massive leukocytic infiltration in the parenchymatous organs of the abdominal cavity. On hematologic cell counting, severe leukocytosis (69.3 x 10(9) cells/liter) and high-grade basophilia (6.9 x 10(9) cells/liter) were evident. Cytologic examination, as well as analysis of expression of leukocyte differentiation antigens by means of flow cytometry, classified blasts, which accounted for about 22% of leukocytes, as biphenotypic cells co-expressing the myeloid marker SWC3 (CD172a) and the lymphoid markers CD5 and CD25. Hematologic features resembled those seen in humans with chronic myeloid leukemia at blast phase.
A 22-month-old, female rabbit was presented with a 1-day history of acute unilateral exophthalmos... more A 22-month-old, female rabbit was presented with a 1-day history of acute unilateral exophthalmos. Ultrasonography and computed tomography (CT) of the orbit revealed an orbital mass. Retrobulbar lymphoma was diagnosed following fine-needle aspiration biopsy (FNAB). Thoracic radiographs were normal, and ultrasonography of the abdomen showed focal hypoechoic thickening of the bowel wall and hypoechoic enlarged lymph nodes. The rabbit was euthanized and histopathology identified the retrobulbar mass as B-cell malignant lymphoma of the Harder's gland. Mesenteric lymph nodes, caecum, and both kidneys were also affected. This is the first documented case of malignant lymphoma of the Harder's gland in a rabbit.
The aim of the study was to investigate if there is a clinically relevant influence of daytime or... more The aim of the study was to investigate if there is a clinically relevant influence of daytime or season and if there are sex-dependant differences in some frequently determined clinical chemistry parameters. The study was performed with 99 1.5- to 2-year old healthy budgerigars of three races. A harmonic regression analysis was performed taking into account linear and cyclic trends over the year. Correlations were investigated by the calculation of Spearman correlation coefficients. Summarizing, it can be said that some circadian, seasonal, as well as sex- and race-dependant influences have been shown. However, although the differences are statistically significant, they were too small to have an impact on clinical decision making. As clinical chemistry results are in practice independent from the influence factors investigated, their meaning and use as a diagnostic tool is further substantiated.
Differentiation between motor and sensory fascicles is frequently necessary in reconstructive per... more Differentiation between motor and sensory fascicles is frequently necessary in reconstructive peripheral nerve surgery. The goal of this experimental study was to verify if centrally motor evoked potentials (MEP) could be implemented to differentiate sensory from motor fascicles, despite the well-known intermingling between nerve fascicles along their course to their distant periphery. This new procedure would enable surgeons to use MEP for placing nerve grafts at corresponding fascicles in the proximal and distal stumps without the need to use time-consuming staining. In ten sheep, both ulnar nerves were exposed at the terminal bifurcation between the last sensory and motor branch. Animals were then relaxed to avoid volume conduction. On central stimulation, the evoked nerve compound action potentials were simultaneously recorded from both terminal branches. In all cases, neurogenic motor nerve action potentials were recorded only from the terminal motor branch. The conclusion was that MEPs can be used for intraoperative differentiation between sensory and motor nerves. Further studies are necessary to develop this method for in situ measurements on intact nerve trunks.
Research in osteoporosis, which is a complex systemic disease, demands suitable large animal mode... more Research in osteoporosis, which is a complex systemic disease, demands suitable large animal models. In pigs, most research has been done in growing minipigs, which probably are not ideal models for postmenopausal osteoporosis. Therefore, our aim was to analyze the effects of ovariectomy (OVX) and nutritive calcium shortage on multiparous Large White sows. 32 animals were randomly assigned to 4 groups in a cross design with OVX vs. sham and physiological calcium supplementation (0.75% calcium) vs. dietary calcium shortage (0.3% calcium). The observation period was 10 months with blood sampling every 2 months for hematological, immunological, and biochemical bone marker measurements. At the termination of the experiment, animals were sacrificed. Samples of trabecular bone of distal radius, proximal tibia, and sixth lumbar vertebra were subjected to micro-computed tomography imaging and ashed afterwards. Dual X-ray absorptiometry scans of the proximal femora were performed with prepared bones being placed in a water bath for mimicking soft tissue. Analyses of bone marker and cytokine profile kinetics, distribution of leukocyte subpopulations, and morphometrical and densitometrical analyses showed no evidence of any impact of OVX or calcium shortage. In conclusion, the skeleton of adult sows of a conventional breed is seemingly protected from effects of OVX and calcium shortage.
This study assessed the influence of driving speed and revolution rate per minute of two reamers ... more This study assessed the influence of driving speed and revolution rate per minute of two reamers on femoral intramedullary pressure increases and fat intravasation. The AO and Howmedica reamers were tested in four groups with different combinations of driving speed and revolution rate per minute in both femurs in a sheep model. The 24 animals were exposed to hemorrhagic shock after midshaft osteotomy and were resuscitated before reaming of both femoral shafts. Controlled reaming was performed at 15 and 50 mm/second driving speed with 150 and 450 revolutions per minute. Fat intravasation and intramedullary pressure were measured by transesophageal echocardiography, Gurd test, and a piezoelectric gauge, respectively. Low driving speed and high revolutions per minute with the smaller cored reamer led to lower intramedullary pressure changes. The same reaming parameters led to greater pulmonary stress during surgery of the second side. Reaming with a smaller cored reamer and modified reaming parameters leads to a lower increase in intramedullary pressure and reduces the amount of fat intravasation. Primary reamed intramedullary nailing should be done after resuscitation at a low driving speed and high revolutions per minute with a smaller cored reamer to minimize the risk of pulmonary dysfunction.
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Papers by Ilse Schwendenwein