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Biomedical subjects

C Wagner-Mann

Publications and source records attributed to C Wagner-Mann.

18 recordsLinked to original sources

Recombinant human granulocyte colony-stimulating factor for treatment of puppies with neutropenia secondary to canine parvovirus infection.

OBJECTIVE: To determine the effect of treatment with recombinant human granulocyte colony-stimulating factor (rhG-CSF) for puppies with neutropenia secondary to canine parvovirus infection. DESIGN: Randomized controlled clinical trial. ANIMALS: 23 puppies. PROCEDURE: Diagnosis was confirmed by use of an ELISA for detection of canine parvovirus antigen in feces, and all puppies received standard treatment for parvoviral enteritis. All puppies had neutropenia (< 1,000 neutrophils/microliter) at the time of admission to the hospital or within 4 days afterward. Eleven puppies were treated with rhG-CSF daily until neutrophil count was > 1,500 cells/microliter; the remaining 12 puppies were not treated with rhG-CSF. RESULTS: We did not detect any significant differences between groups regarding duration of hospitalization, neutrophil count when neutropenia was first detected, lowest neutrophil count, or time until neutrophil count was > 1,500 cells/microliter. CLINICAL IMPLICATIONS: Results suggest that treatment with rhG-CSF may not be beneficial in puppies with neutropenia secondary to canine parvovirus infection.

Animals↗

Subchronic use of the St. Jude centrifugal pump as a mechanical assist device in calves.

The purpose of this experiment was to study the effects of the St. Jude Lifestream centrifugal pump on hemodynamic and hematologic parameters and the incidence of postmortem findings in a subchronic ex vivo left ventricular assist animal model. Five calves were implanted with the pump as a left ventricular assist device (left atrial to thoracic aorta bypass) and studied for 96 h of continuous pumping under identical conditions. Heparin (100 IU/kg) was administered only in the initial saline pump prime. Throughout the protocol, mean arterial and central venous pressures averaged 102.1 +/- 4.6 and 3.4 +/- 2.2 mm Hg, respectively. Pump flow was 47.8 +/- 8.4 ml/kg/min at a mean pump speed of 1,676.3 +/- 106.1 rpm. No clinical abnormalities or mechanical malfunctions attributable to the pump were detected during the 96 h of continuous pumping for each calf. Mean plasma-free hemoglobin after 96 h was 3.9 +/- 3.7 mumol/L (p = 0.337 compared to baseline). At post mortem, renal infarctions were detected in 1 calf. No other pump-associated lesions were detected in any of the other calves. We have concluded that the St. Jude Lifestream centrifugal pump functions reliably during 96 h of continuous left heart bypass in a calf model.

Animals↗

Subchronic centrifugal mechanical assist in an unheparinized calf model.

The purpose of this study was to determine whether the major centrifugal pumps currently in use in the United States (Medtronic, BioMedicus BioPump and Carmeda-coated BioPump, Sarns 3M centrifugal pump, and St. Jude Medical Lifestream) could function as left mechanical assist devices in the subchronic (72 h) unheparinized calf model. Calves were instrumented for left atrial to aorta ex vivo assist, and the pump flow was set at 3.5 +/- 0.4 L/min. Two calves (Sarns 3M and St. Jude) survived 72 h of pumping without clinical complications. The other 2 calves died at 62 and 66 h (Medtronic BioPump and Carmeda-coated BioPump, respectively); both had pelvic limb paralysis. The seal of the Sarns 3M pump head ruptured after approximately 36 h of pumping and required replacement. On postmortem examination, pump-associated thromboembolic lesions were detected in 3 of the 4 calves in one or more of the following organs: kidneys, pancreas, abomasum, duodenum, ileum, spleen, and lumbar spinal cord. The calf with the Sarns 3M pump had no discernable lesions. Because of the clinical abnormalities and postmortem lesions in the unheparinized calf model, it was suggested that anticoagulation is necessary for conducting centrifugal mechanical assist studies in calves using presently available technology.

Analysis of Variance↗

Endoscopic and surgical retrieval of fishhooks from the stomach and esophagus in dogs and cats: 75 cases (1977-1993)

Medical records of 3 cats and 72 dogs that had a fishhook endoscopically or surgically retrieved from the stomach or esophagus were reviewed. Endoscopic retrieval was successful in 41 of 62 (66%) animals, and retrieval time and hospitalization time for endoscopic retrieval were significantly shorter than times for surgical retrieval. Rate of failure of endoscopic retrieval was higher for animals with treble-barb, rather than single-barb, fishhooks. Whether a fishhook could be successfully retrieved endoscopically was independent of body weight, amount of time the fishhook had been present, location of the hook, and orientation within the esophagus.

Animals↗

Improving clinical outcome with centrifugal mechanical assist for postcardiotomy ventricular failure.

Between October 1986 and May 1994, 65 patients undergoing cardiac surgery required centrifugal mechanical assist devices to separate from cardiopulmonary bypass. This experience was arbitrarily divided into early (n = 33) and recent (n = 32) groups for the purpose of comparing trends in morbidity and mortality. The incidence of mechanical assist application decreased from 2.19% in the early group to 0.96% in the recent group (p < 0.0001). Ability to wean patients from centrifugal assist increased from 33% in the early group to 53% in the more recent group, and hospital survival increased from 15 to 28%. The median chest tube drainage during the first 24 h decreased from 3,245 ml to 1,535 ml, and the incidence of renal failure decreased from 39.4% and 18.8% in the more recent group. Clinically relevant improvement in patient outcome following application of centrifugal mechanical assist for postcardiotomy ventricular failure is being observed.

Adult↗

Effects of three occlusive dressing materials on healing of full-thickness skin wounds in dogs.

The effects of 3 occlusive dressing materials and a standard, nonadherent dressing material on healing of full-thickness skin defects were evaluated in dogs. Two wounds measuring 2 x 2 cm were created bilaterally (4 wounds/dog) on the dorsolateral aspect of the trunk of 12 Beagles. Wound treatments were evenly distributed between 4 sites, using a Latin square design. Treatments evaluated were: equine amnion (group A), biosynthetic hydrogel dressing (group B), transparent polyethylene sheeting (group T), and a semi-occlusive rayon/polyethylene, nonadherent dressing (group C). Rates of contraction and epithelialization of group-A wounds were significantly greater than those of wounds of groups C, B, and T. On days 14, 21, and 28, mean percentage of wound contraction and mean percentage of total wound healed in group A exceeded those wounds in groups C, B, and T. On day 28, wounds in group A were significantly smaller than wounds in groups B and T, but were not significantly smaller than wounds in group C. All wounds in group A achieved 100% healing during the 28-day study period. Mean time for complete healing of group-A wounds was 21 days. The percentages of wounds completely healed by day 28 for groups B, C, and T were 25, 67, and 25%, respectively. Results indicate that use of equine amnion as an occlusive biological dressing on full-thickness wounds in dogs increases rate of healing.

Amnion↗

Multiple effects of ryanodine on intracellular free Ca2+ in smooth muscle cells from bovine and porcine coronary artery: modulation of sarcoplasmic reticulum function.

1. The effects of ryanodine and caffeine on intracellular free Ca2+ concentration ([Ca2+]i) were studied by use of fura-2 microfluorometry in single smooth muscle cells freshly dispersed from bovine and porcine coronary artery. 2. Bovine and porcine cells demonstrated similar sensitivities to 10 min of exposure to ryanodine in physiological salt solution (PSS), as determined by comparable dose-dependent decreases in the subsequent [Ca2+]i transient induced by 5 mM caffeine. 3. Ryanodine (10 microM) caused a significant increase in [Ca2+]i to a plateau level 27 +/- 3% and 38 +/- 4% above baseline [Ca2+]i (baseline [Ca2+]i = [Ca2+]i at 0 min) in porcine and bovine cells, respectively, when bathed in PSS. In bovine cells the time required to reach 1/2 the plateau level was only 3 min versus 6 min for porcine cells. 4. The ryanodine-induced plateau increase in [Ca2+]i was 35 +/- 5% above baseline for bovine cells bathed in 0 Ca PSS (PSS including 10 microM EGTA with no added Ca2+), but only 7 +/- 3% above baseline in porcine cells during 10 min exposure to 10 microM ryanodine. In bovine cells [Ca2+]i showed proportional increases when extracellular Ca2+ was increased from the normal 2 mM Ca2+ PSS to 5 and 10 mM. 5. Cells pretreated with caffeine in 0 Ca PSS, which depleted the caffeine-sensitive sarcoplasmic reticulum Ca2+ store, showed no increase in [Ca2+]i when challenged with 10 microM ryanodine. The ryanodine-associated increase in [Ca2+]i, which was sustained in 0 Ca PSS during the 10 min ryanodine exposure in cells not pretreated with caffeine, suggests that ryanodine releases Ca2+ from the sarcoplasmic reticulum, but also inhibits Ca2+ efflux.6. Intracellular free Ba2+ ([Ba24],) was measured with fura-2 microfluorometry to define further the Ca2" efflux pathway inhibited by ryanodine; specifically, Ba2+ is not transported by the Ca2" pump, but will substitute for Ca2" in Na+-Ca24 exchange. In porcine cells pretreated with caffeine in 0 Ca PSS to deplete the caffeine-sensitive sarcoplasmic reticulum Ca2+ store, depolarization with 80 mM K4 in 2 mM external Ba24 caused a 100 +/- 6% increase in fura-2 fluorescence ([Ba2+]j). During the 17.5 min 0 Ca PSS recovery from depolarization, exposure to 10 microM ryanodine inhibited the removal of [Ba24]i by 69 + 3% when compared with control (0 Ca PSS without ryanodine).7. It was concluded that in bovine and porcine smooth muscle cells: (a) ryanodine (> 10 microM) releases Ca24 from the sarcoplasmic reticulum; (b) ryanodine ( 10O microM) decreases Ca24 efflux, probably by inhibition of Na+-Ca2+ exchange; (c) the sarcoplasmic reticulum Ca24 store may be larger in bovine than in porcine smooth muscle cells; thus, porcine cells have a relatively greater reliance on Ca24 influx to increase [Ca2+]i.

Animals↗

Comparison of intranasal and intratracheal oxygen administration in healthy awake dogs.

Intranasal (IN) and intratracheal (IT) oxygen administration techniques were compared by measuring inspired oxygen concentrations (FIO2) and partial pressures of arterial oxygen (PaO2) in 5 healthy dogs at various IN (50, 100, 150, and 200 ml/kg of body weight/min) and IT (10, 25, 50, 100, 150, 200, and 250 ml/kg/min) oxygen flow rates. Intratracheal administration of oxygen permitted lower oxygen flow rates than IN administration. Each IT oxygen flow rate produced significantly higher FIO2 and PaO2 than the corresponding IN flow rate. An IT oxygen flow rate of 25 ml/kg/min produced FIO2 and PaO2 values equivalent to those produced by an IN oxygen flow rate of 50 ml/kg/min. An IT oxygen flow rate of 50 ml/kg/min produced FIO2 and PaO2 values equivalent to those produced by IN oxygen flow rates of 100 and 150 ml/kg/min. All IT oxygen flow rates greater than or equal to 100 ml/kg/min produced FIO2 and PaO2 values that were greater than FIO2 and PaO2 values produced by IN oxygen flow rates of 200 ml/kg/min. The lowest flow rates studied (50 ml/kg/min, IN, and 10 ml/kg/min, IT) produced PaO2 capable of maintaining 97% hemoglobin saturation, which should be adequate for most clinical situations. Arterial blood gas analysis and FIO2 measurements are necessary to accurately guide oxygen flow adjustments to achieve the desired PaO2 and to prevent oxygen toxicity produced by excessive FIO2.

Administration, Intranasal↗

Primary action of endothelin on Ca release in bovine coronary artery smooth muscle cells.

Intracellular free Ca concentrations (Cai) were determined by fura-2 microfluorometry in single freshly dispersed cells to differentiate endothelin (ET)-induced Ca release from Ca influx through voltage-gated Ca channels (VGCC). In physiological solution ET (10(-8) M) significantly (P less than 0.05) increased Cai 23 +/- 3% (+/- SE) above baseline; this increase was not significantly attenuated by 2 x 10(-4) M lanthanum, a blocker of VGCC, or Ca-free solution. When the sarcoplasmic reticulum was depleted of Ca by prolonged treatment with 5 x 10(-3) M caffeine, depolarization with 80 mM K (80K; or 30K) plus ET did not increase Cai above that induced by 80K (or 30K) in caffeine alone. In contrast, 10(-6) M BAY K 8644, instead of ET in the protocol, significantly (P less than 0.05) increased Cai above that induced by 80K (or 30K). ET released Ca from the caffeine-sensitive internal store but was not rapid and transient like caffeine-induced release, which elicited a peak Cai increase in less than 1 min; instead, release was more gradual and prolonged with Cai peaking in greater than 2 min, thus resembling the response to 10(-5) M ryanodine. With two ET exposures, either a transient nonrepeatable increase in Cai or a delayed, but sustained, increase in Cai resulted, similar to the response to ryanodine. These data indicate that in freshly dispersed bovine cells the predominant mechanism by which ET increases Cai is release of Ca from the sarcoplasmic reticulum; if any increase in L-type voltage-gated Ca influx occurred, it was minimal and matched by efflux.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

Endothelin mediates Ca influx and release in porcine coronary smooth muscle cells.

Endothelin (ET)-induced changes in intracellular free Ca (Cai) in freshly dispersed coronary artery smooth muscle cells were determined using fura-2 microfluorometry to differentiate the action of ET on Ca influx vs. release from internal stores. Comparison was made with caffeine (CAF)-induced Ca release from the sarcoplasmic reticulum (SR) to determine whether ET acts on the same Ca store. In physiological external solution, ET (5 x 10(-8) M) induced a rapid (within 90 s), transient (less than 2.5-min duration) 70% increase in Cai above baseline (n = 20). Pretreatment with diltiazem (10(-4) M; n = 10) did not change the amplitude or shape of the ET-induced Cai transient. In Ca-free solution, ET elicited a Cai response similar in duration but smaller (P less than 0.05) in peak magnitude (31% increase; n = 7). CAF (5 x 10(-3) M) also elicited a rapid (less than 60 s), transient 82% increase in Cai (n = 7). In the continued presence of CAF, ET caused no change in Cai. In contrast, ET elicited a transient 69% increase in Cai (n = 8), and in the continued presence of ET, CAF caused a 24% increase in Cai. Ryanodine (5 x 10(-5) M) suppressed the subsequent ET-induced Cai transient. These data on porcine cells suggest ET induces a rapid release of Ca from a CAF- and ryanodine-sensitive store and causes rapid influx of Ca, which is different from bovine smooth muscle cells. The return of Cai to baseline values in the continued presence of ET suggests the ET-sensitive store is depleted and increased Ca efflux matches Ca influx.

Animals↗

Platelet function testing in the pony.

Platelet isolation techniques and platelet function were evaluated in 35 adult ponies. Platelet recovery from whole blood was consistent and the preparation of platelet rich plasma was facilitated by an enhanced erythrocyte sedimentation rate. All platelet samples aggregated in response to 10 microM ADP. However, concentrations of ADP as high as 100 microM did not elicit significant 14C-serotonin release. Collagen induced irreversible platelet aggregation and 14C-serotonin release in all samples. The threshold dose for collagen in most ponies was 1.5 micrograms. Arachidonic acid (500 microM) failed to induce irreversible platelet aggregation or 14C-serotonin release in any of the samples evaluated. Pony platelets were nonresponsive to epinephrine (5.5 microM).

Adenosine Diphosphate↗

Thermal and heart rate response to ultrasonic exposure in the second and third trimester dog fetus.

A total of 39 fetuses from five pregnant dogs were used in this study. Following pentobarbital anesthesia of the dams the gravid uterus was exposed and partially exteriorized. Fetal and maternal electrocardiograms were recorded, along with fetal abdominal temperatures, during ultrasound exposures of 3.4 MHz and 2, 4, 6, 8 or 12 W/cm2 (continuous wave), spatial average intensities, for 6 minutes. Baseline fetal abdominal temperatures were 35.2 +/- 1.5 (SD) degrees C. Baseline fetal heart rates were 176.8 +/- 4.3 (SD) beats per minute. These studies indicate that the product of intensity and time of exposure, under the conditions of these experiments, is directly related to increases in fetal abdominal temperature and fetal heart rate.

Animals↗

Pharmacodynamics and pharmacokinetics of orally administered bishydroxycoumarin in the goat.

Eight goats, 2 nontreated controls and 6 treated, were used to study the pharmacodynamics and pharmacokinetics of bishydroxycoumarin. In 5 of the 6 treated goats, there was a significant relationship between prothrombin times and drug concentrations. Activated clotting times did not change with time in either the controls or the treated goats. Five of 6 treated goats reached a plateau of drug concentration after 24 to 36 hours. Lag times for onset of pharmacologic effect ranged from 12 to 24 hours. The one goat (No. 3) that did not respond in concert with the other 5 was extremely nervous and became anorectic during the period of indoor confinement.

Animals↗

A comparison of standard femoral head and neck excision and femoral head and neck excision using a biceps femoris muscle flap in the dog.

Sixteen normal 20 to 30 kg dogs had standard femoral head and neck excision (8 dogs) or femoral head and neck excision with interposition of a biceps muscle flap (8 dogs). Lameness lessened at week 6, and did not differ between groups; neither group returned to a completely normal gait. Weightbearing decreased on the operated pelvic limb compared to controls (forceplate analysis). Weightbearing force of the muscle flap dogs was significantly less at weeks 6 and 16 than that of the standard femoral head and neck excision dogs. The operated limb of both groups was shortened; shortening was significantly greater for the muscle flap group. Hip extension was limited in both groups. Both groups had decreased (more acute) hip, stifle, and hock angles measured in standing position. Thigh muscle atrophy was more pronounced in the muscle flap group at week 6. More soft tissue was interposed in the muscle flap group at necropsy compared to the group with standard femoral head and neck excision, but the difference was not statistically significant. Skeletal muscle fibers were present in the interposed fibrous connective tissue of the muscle flap group, and the healed surfaces were smoother than those of the standard femoral head and neck excision group.

Animals↗

A comparison of nonthreaded, enhanced threaded, and Ellis fixation pins used in type I external skeletal fixators in dogs.

Three different pin types (Ellis, enhanced threaded, and nonthreaded) were used in type 1 external skeletal fixation after transverse osteotomy of the radius and ulna in 12 skeletally mature dogs. Dogs were placed into three groups of four dogs based on the pin type used. Axial extraction forces were determined for each of the pin types after 8 weeks of weight bearing (chronic study). Nine contralateral radii were used to determine axial extraction forces for nine of each pin type not subjected to weight bearing forces (acute study). The force required for extraction of the enhanced threaded and Ellis pins in the chronic and acute studies was not significantly different. The force required to extract the nonthreaded pins was significantly less than that required for the other two pin types. Ground reaction forces had returned to levels measured before surgery by 2 weeks after surgery in the enhanced threaded and Ellis pin groups, however, dogs in the nonthreaded pin group required 4 weeks until normal ground reaction forces were measured. Radiographic evaluations 1, 2, 4, 6, and 8 weeks after surgery showed no difference among groups in the number of pin tract radiolucencies, however, the enhanced threaded pins had caused more trans-cortical chip fractures than the other two pin types. None of the pins broke during the eight-week chronic study.

Animals↗

Plasma granulocyte colony-stimulating factor concentrations in neutropenic, parvoviral enteritis-infected puppies.

We evaluated the temporal relationship between neutrophil numbers and plasma granulocyte colony-stimulating factor (G-CSF) concentrations in dogs infected with canine parvovirus, a common infectious cause of neutropenia. G-CSF is produced in response to neutropenia, infection, or inflammation, and results in the production and release of neutrophils from the bone marrow. Adequate numbers of functional neutrophils are necessary for protection from infection, and the timely production of G-CSF is a crucial response to certain diseases. The relationship between peripheral neutrophil numbers and plasma G-CSF concentrations during the course of an infectious disease characterized by neutropenia has not been described previously in dogs. Eight mixed-breed puppies were given an oronasal challenge with canine parvovirus, and peripheral neutrophil numbers as well as plasma G-CSF concentrations were measured daily. G-CSF was not detectable in plasma of any dog before the onset of neutropenia, but G-CSF became detectable just after the onset of neutropenia in the 7 dogs that developed clinical illness. Neutropenia persisted or worsened for at least 2 days after plasma G-CSF became detectable in all 7 dogs. Neutrophil nadir, the highest plasma G-CSF concentrations, and the most severe clinical illness occurred concurrently in most dogs. Although 1 dog died while still neutropenic, plasma G-CSF concentrations declined before resolution of neutropenia in the other 6 dogs, and were again below the limits of detection in 5 of the 6 dogs at the time of resolution.

Animals↗

Feline osteosarcoma: 145 cases (1990-1995).

Feline osteosarcoma (OSA) is a rare tumor in cats. Ninety (62%) of feline OSAs detailed in this study arose from the skeleton, and 55 (38%) arose from extraskeletal sites. Fifty OSAs originated in the appendicular skeleton, and 40 OSAs originated in the axial skeleton. Extraskeletal OSA sites included subcutaneous sites (n=44), with an apparent prevalence for sites commonly used for vaccination. Other locations included ocular/orbital (n=4), oral (n=3), intestinal/omental (n=3), and mammary sites (n=1). Survival data was available for 74 cases. When considered as a group, cats with either appendicular (mean, 11.8 mos) or extraskeletal (mean, 12.67 mos) OSA survived longer than those with axial (mean, 6.07 mos) OSA. Regardless of the type of feline OSA, aggressive surgical excision with or without ancillary therapy appeared to be the most effective form of treatment.

Animals↗