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Biomedical subjects

P F Rumph

Publications and source records attributed to P F Rumph.

At least 19 recordsLinked to original sources
PubMed1999

Interday variation in vertical ground reaction force in clinically normal Greyhounds at the trot.

OBJECTIVE: To determine the effect of interday variation on vertical ground reaction force variables in dogs. ANIMALS: 52 clinically normal Greyhounds of either sex weighing between 22 and 35 kg. PROCEDURE: Dogs were led at a trot across a floor-mounted force platform to determine vertical ground reaction force variables (peak [PFz] and impulse [IFz]) from hind limbs. Data were collected from each dog on 3 consecutive days. Variance components were estimated, using maximal likelihood to evaluate contributions of interday variation within dogs and variation attributable to dogs and repetitions. An ANOVA was used to test significance of interday variation within dogs and day within dog interactions. RESULTS: PFz, IFz, or both differed significantly from day to day for 29 of 52 dogs. Only PFz differed significantly among days for 16 dogs, and only IFz differed among days for 5 dogs. The PFz and IFz differed significantly from day to day in 8 dogs. Using ANOVA, the difference for PFz and IFz among days within dogs was significant. CONCLUSIONS: Effect of day within dog variation (interaction) should be considered as a component in statistical models in which data from 1 day are evaluated against data from the same subject on another day. We propose a statistical model that incorporates an accommodation for interday variation. Investigators should determine the factors that affect their studies, including the extent of interday variation, and compensate for the variation attributable to each factor in the statistical models used to analyze their data.

Analysis of Variance↗
PubMed1998

An environmental chamber for investigating the evaporation of volatile chemicals.

An inexpensive test chamber has been constructed that provides an environment appropriate for testing the effects of temperature and chemical interactions on gaseous emissions from test solutions. Temperature, relative humidity, and ventilation rate can be controlled and a well-mixed atmosphere can be maintained. The system is relatively simple and relies on heated tap water or ice to adjust the temperature. Temperatures ranging from 9 to 21 degrees C have been maintained. At an average temperature of 15.1 degrees C, temperatures at any location within the chamber vary by no more than 0.5 degree C, and the temperature of the test solution within the chamber varies by no more than 0.1 degree C. The temperatures within the chamber are stable enough to generate precise steady-state concentrations. The wind velocities within the chamber are reproducible from run to run. Consequently, the effect of velocity on the rate of evaporation of a test chemical is expected to be uniform from run to run. Steady-state concentrations can be attained in less than 1 hour at an air exchange rate of about 5 per hour.

Air Pollutants↗
PubMed1998

Ground reaction forces in Greyhounds with tibial nerve injury.

OBJECTIVES: To measure ground reaction force variables during lameness resulting from impaired tibial nerve function and to determine whether these variables changed significantly as recovery progressed. ANIMALS: 11 healthy Greyhounds of either sex, weighing between 22 and 39 kg. PROCEDURE: On 3 consecutive days before surgery, ground reaction forces were measured by force platform gait analysis at the trot. In dogs under general anesthesia, the left tibial nerve was crushed proximal to innervation of the gastrocnemius muscle. Gait analyses were repeated on days 8 to 10, 28 to 30, 43 to 45, 58 to 60, and 90 to 92 after surgery. Ground reaction force variables and stance time were compared among the 3-day clusters. RESULTS: 10 days after surgery, all dogs had weight-bearing lameness attributed to paralysis of muscles in the caudal compartment of the crus. Nerve regeneration resulted in functional recovery within 3 months. Decreases in vertical force were significant 10 days after surgery; thereafter, changes reflected gradual return of load bearing, with the most marked improvement between 10 and 45 days. At 90 days, vertical force variables were within 3% of presurgical values. Stance time for the left hind limb was significantly longer at 10, 30, and 45 days after surgery and was seen in all dogs, but returned to within 1 % of preoperative stance time at 90 days. The effect of tibial nerve dysfunction on braking or propulsive force was not significant. CONCLUSIONS AND CLINICAL RELEVANCE: The significant changes in vertical ground reaction forces in hind limbs of dogs during lameness that resulted from impaired tibial nerve function are detectable, as is response during recovery, by use of force platform analysis.

Animals↗
PubMed1997

Effects of selection and habituation on vertical ground reaction force in greyhounds.

OBJECTIVE: To determine effect of dog selection and habituation on vertical ground reaction force variables. ANIMALS: 133 Greyhounds of either sex, weighing between 22 and 39 kg. PROCEDURE: Vertical ground reaction force variables (peak [PFz] and impulse [IFz]) for hind limbs were studied in dogs at 3 levels of habituation. Dogs of group 1 (n = 81) did not have prior experience with the gait analysis routine. Group-2 dogs (n = 52) were selected for having an amiable disposition, and were first evaluated after participating in an intermediate habituation routine (group 2a). These dogs were reevaluated after undergoing the full habituation routine (group 2b). RESULTS: 3 of the ground reaction force variable differed significantly between dogs of groups 1 and 2 (a and b). Dogs that had not been habituated to the gait analysis routine (group 1) had significantly longer stance times than did dogs that had been more carefully selected and habituated. Intradog coefficients of variation for PFz and the IFz were significantly greater in group-1 dogs. The PFz for group-2a dogs was significantly greater than that for group-1 dogs. Differences identified between groups 2a and 2b were more likely to be attributed to habituation only. These included significantly shorter stance time and lower intradog coefficient of variation for IFz in dogs having the highest level of habituation. CONCLUSION: Selection and habituation have measurable effects on vertical ground reaction force data obtained from trotting dogs. These include significantly shorter hind limb stance times, lower impulses of vertical force, with smaller coefficients of variation for peaks and impulses of vertical force within dogs. CLINICAL RELEVANCE: In controlled studies where critical decision making is based on gait analysis data, careful selection of subjects and habituation will significantly improve precision of the data and has the potential to reduce the subject or repetition sample size.

Animals↗
PubMed1996

Tumor necrosis factor-alpha (TNF-alpha) in canine osteoarthritis: Immunolocalization of TNF-alpha, stromelysin and TNF receptors in canine osteoarthritic cartilage.

The presence and distribution of tumor necrosis factor-alpha (TNF-alpha), TNF receptors and stromelysin [matrix metalloproteinase 3 (MMP-3)] in articular cartilage were evaluated in an iatrogenically induced model of osteoarthritis (OA). Eleven adult male dogs were assigned randomly to a control group (N = 4) or an OA group (N = 7). Osteoarthritis was created by surgical transection of the cranial cruciate ligament of one stifle joint. Both femoral condyles were sampled 3 months post-surgery at necropsy and immunohistochemically analyzed for the presence of the aforementioned cytokines and receptors. Chondrocytes stained for TNF-alpha and TNF receptors in control articular cartilage, spanning an area encompassing most of the middle and deep zones. Positive matrical and chondrocytic staining for TNF-alpha, TNF receptors, and stromelysin was present in OA articular cartilage. Staining varied in intensity and distribution and was dependent of the severity of the lesion. Smooth muscle cells of arteries and arterioles (periarticular synovial membrane) were stained for only one (p55) of two TNF receptors; this staining was confined to control tissues. Results indicate that the differential expression of TNF-alpha and its receptors may be important in the normal maintenance of articular cartilage. The increased presence of TNF-alpha and its receptors in articular cartilage with mild osteoarthritic changes suggests a role in the development of early OA. Regulating TNF-alpha may be an important component in the treatment of OA.

Animals↗
PubMed1996

Morphology of the musculus articularis genus in dog with description of ectopic muscle spindles.

The gross morphology of the musculus articularis genus and the location of muscle spindles at its point of insertion were studied in 18 adult dogs. The m. articularis genus was usually small and bipartite. From its originate on the cranial surface of the distal femur, it passed distally to terminate at the femoropatellar-joint capsule surface and extend into the synovial membrane. Although the m. articularis genus was usually composed of two parts, only a medial part was present in some dogs and was entirely absent in one specimen. Innervation to the m. articularis genus was provided by a branch of the femoral nerve. Muscle spindles were abundant in the termination of the muscle. spindles were abundant in the termination of the muscle. Frequently, the spindles were not in contact with muscle fibers (dissociated). Muscle spindles were located in close proximity to the surface of the synovial membrane. Morphological adaptations of the m. articularis genus support its potential function as a monitor of joint movement rather than an extensor of the stifle joint.

Animals↗
PubMed1996

Nonlinear dynamics stability measurements of locomotion in healthy greyhounds.

OBJECTIVE: To characterize normal locomotion of dogs, using nonlinear dynamic stability measurements to analyze two-dimensional kinematic data. ANIMALS: 5 healthy, orthopedically sound Greyhounds. PROCEDURE: Data were studied by sequentially constructing phase plane portraits from the angular velocity and displacement data; creating first-return (Poincaré) maps from periodically sampled data; and evaluating the dynamic stability of the gait, using Floquet multipliers calculated from the assembled data. Retroreflective markers were placed on the left craniodorsal aspect of the iliac spine, greater trochanter, lateral epicondyle of the femur, lateral malleolus, and fifth metatarsophalangeal joint. Each dog was repeatedly led at a trot along a 10-m runway. Data were collected, using a video-based, two-dimensional motion measurement and analysis system. Dogs were considered a nonlinear system and were represented by the joint angular displacements and velocities. Phase plane portraits and first-return maps were constructed to analyze the smoothed data. The Floquet theory was then used to investigate the local stability of critical points of the discrete map. RESULTS: The femorotibial joint had the highest angular velocity, ranging from -2.5 to 4.9 radians/s. Tarsal joint velocity ranged from -2.7 to 3.2 radians/s, and the coxofemoral angle had the lowest range of -2.2 to 2.2 radians/s. The points on the first-return maps converged to the 45 degrees diagonal line and were clustered together. The largest Floquet multiplier averaged 0.452, which characterized the stability of this population and will be used to draw a comparison between this and future work. CONCLUSIONS: Nonlinear dynamics can be effectively used to analyze two-dimensional kinematic data from animal models to quantify the dynamic stability of animal locomotion through precise mathematical measurements. The method is general and can be applied to normal or abnormal gaits. CLINICAL RELEVANCE: Point mapping and quantitative measurement of joint movement have several advantages associated with the application to animal and human locomotion. The clinician can visually distinguish the normal gait pattern from abnormal patterns to assist in the diagnosis of musculoskeletal abnormalities (diseases).

Animals↗
PubMed1994

Ground reaction force profiles from force platform gait analyses of clinically normal mesomorphic dogs at the trot.

Force platform analysis of gait provides ground reaction force information that can be used to study limbs with normal or abnormal function. When combined, the interrelated variables of ground reaction forces give a more thorough description of gait than when used individually. To describe the pattern of ground reaction forces in clinically normal, conditioned, mesomorphic dogs, we studied the data from platform gait analyses of 43 dogs. Mediolateral (Fx), craniocaudal (Fy), and vertical (Fz) forces were measured and recorded. Torque (Tz) around the vertical axis also was calculated. Mean stance times for forelimbs and hind limbs were 0.278 and 0.261 second, respectively. Among dogs, ground reaction forces were normalized and expressed as percentage of body weight (%bw). The vertical (Fz) peak, average force during stance phase, and force vs time impulses were 106.68, 60.82, and 17.2 %bw in forelimbs, and were 65.11, 35.3, and 9.33 %bw in hind limbs. The forelimb braking/propulsive (Fy) peaks were -16.74 and +6.73 %bw. In hind limbs, these peaks were -3.76 and +7.69 %bw. The usual mediolateral force (Fx) pattern found in forelimbs was laterally directed, with average peak magnitude of 6.69 %bw, whereas the hind limb patterns were variable.

Animals↗
PubMed1993

Vertical ground reaction force distribution during experimentally induced acute synovitis in dogs.

The pattern of vertical ground reaction force redistribution among limbs during episodes of acute synovitis of the stifle in 12 mixed-breed dogs was investigated as an adjunct to a blinded nonsteroidal anti-inflammatory drug efficacy study. Without regard to drug efficacy groupings, the redistribution of vertical forces before and during the acute synovitis episode was evaluated by analysis of gait, using a force platform. Acute synovitis was induced by intrasynovial injection of sodium urate crystals. Simultaneously, each dog was given 1 of 4 treatment regimens, including IV injection of sterile saline solution (as a negative control), phenylbutazone (as a positive control), or 1 of 2 proprietary nonsteroidal anti-inflammatory drugs. Postinjection analyses took place at 2, 4, 8, 12, 24, and 36 hours. The peak vertical force redistribution in the 3 untreated limbs of the dogs was described. The greatest redistribution was observed 4 hours after substance injection when the synovitis was clinically at maximum. Thereafter, there was steady improvement and the dogs had a clinically normal gait 24 hours after substance injection. During synovitis, peak vertical force increased in the contralateral hind limb. During the more severe synovitis episodes, force was decreased in both forelimbs. There was good correlation between severity of lameness and peak vertical force response in the contralateral hind limb. Results of the study indicate that the untreated limbs of the same animal should not be used as a control during acute lameness studies.

Animals↗
PubMed1992

Ultrasonography of the canine prostate with histologic correlation.

The present study assessed the canine prostate gland using B-mode real-time ultrasonography and correlated these findings with corresponding histologic sections. The prostate glands of 10 dogs were suspended in a saline bath and were scanned with an ultrasound probe. The glands were fixed and histologic sections were made. The sonograms were visually compared with the histologic sections. Areas having high collagenous tissue content appeared hyperechoic on the ultrasound scans. This hyperechogenicity was seen in the diffusely hyperechoic immature gland, the hyperechoic periurethral stroma, and the hyperechoic butterfly-shaped area seen on transverse scans. The butterfly-shaped area was isoechoic, with an elongated oval area seen on transverse scans. Areas of glandular epithelial content appeared hypoechoic on ultrasound scans. No zones comparable to the human prostate were observed.

Journal Article↗
PubMed1992

The apical ligaments of the penis of the goat and sheep.

The penile apical ligaments of 13 goats and 8 sheep were dissected and described. Unlike the single apical ligament of the bull penis, both goats and sheep had one ligament on each side of the apex of the penis with no apparent connection over the dorsal surface. These lateral apical ligaments consisted of substantial connective tissue fibers that arose from the outer layers of the tunica albuginea and varied from 6.0 to 10.0 cm in length. The left apical ligament was longer and thicker than the right. The left apical ligament of the sheep penis was divided into a dorsal and a ventral branch. Both the goat and sheep possessed flattened perivenous ligaments that originated from the apical fascia and extended caudally along each side of the dorsal vein of the penis.

Animals↗
PubMed1992

Ultrasonographically detectable ring structure in avian (Gallus gallus) egg yolks.

After a preliminary finding of ultrasonographically detectable ring structure within the yolk of avian eggs, a study was initiated to investigate these properties. Ultrasonographically detectable alternating hyperechoic and hypoechoic rings within the egg yolk were found to be consistent but variability occurred in ring numbers, thickness, and clarity. Rings were best seen at two days post oviposition and were not affected by refrigeration or heating of the yolks. The usefulness of rings in experimental studies of yolk content of lipoprotein is postulated.

Animals↗
PubMed1990

Ultrasonographic examination and measurement of ram testicles.

Ten adult rams were used in a study to compare ultrasonographic and physical measurements of testicles. Scrotal circumference measurements were correlated with both physical and ultrasonographic measurements and with semen analysis results. Scrotal circumference correlated well with most of the physical and ultrasonographic measurements and with semen motility and percent abnormalities. Ultrasonographic measurements correlated with scrotal circumferences but not with the semen analysis. There were significant differences in physical and ultrasonographic measurements of testicle circumference and diameter, especially when the ultrasonographic measurements were made through the intact scrotal wall. There appear to be problems in the accuracy of ultrasonographic measurements of testicle size in rams.

Journal Article↗
PubMed1990

Evaluation of drug-induced prostatic involution in dogs by transabdominal B-mode ultrasonography.

The relative antiandrogen-induced prostate involution activity of the newly synthesized hydroxyflutamide pro-drug was compared with that of flutamide in 25 Beagles. Secondary antiandrogen activity of both drugs on the testes and mammary tissue was investigated. Daily oral administration of both compounds at 2 dosages (ie, 2.5 and 5.0 mg/kg of body weight) during a 7-week period was monitored by transabdominal ultrasonography of the prostate twice a week. Cross-sectional area estimates of the prostate gland calculated from oblique dorsoventral, and transverse sonographic measurements were diminished significantly in some of the treated dogs as early as day 14 of drug administration. All treated dogs had significant differences in reduction by day 47. Involution was related directly to dose (P less than 0.05), but no difference was observed between test compounds. Differences in secondary antiandrogen activity were not remarkable. Flutamide was not found to have any activity advantage in vivo over hydroxyflutamide. It was concluded that ultrasonography can be a highly effective means of monitoring prostate size, and of monitoring drug-induced involution over time.

Animals↗
PubMed1984

Ultrasonographic detection of fistulous tracts and foreign objects in muscles of horses.

The results from water-bath studies on equine muscle in which foreign material had been inserted and then scanned ultrasonographically were compared with the results from scanning of the muscles of horses hospitalized for diagnosis of suspected foreign objects embedded in muscle. The water-bath studies showed that bone, wood, and large tendons all will demonstrate acoustic shadowing, but that subtle differences in the characteristics of the relative hyperechogenicity and acoustic shadows facilitate elimination of certain considerations in the differential diagnosis. Ultrasonography was effective in locating fistulous tracts and bone sequestra. A protocol for diagnosis of suspected foreign objects imbedded in muscle was proposed.

Animals↗