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Biomedical subjects

N C Palmer

Publications and source records attributed to N C Palmer.

At least 19 recordsLinked to original sources
PubMed1985

Atrial septal defect of the persistent ostium primum type with hypoplastic right ventricle in a Welsh pony foal.

Valvular competency of the foramen ovale (patent foramen ovale) is regarded as a common finding in the neonatal foal and usually occurs in isolation. True atrial septal defects appear to be uncommon and are usually associated with other congenital cardiac lesions. The present report describes a case of atrial septal defect type 1 (persistent ostium primum) complicated by hypoplastic right ventricle, and tricuspid dysplasia, in a Welsh Mountain pony foal, and discusses the embryogenesis of the abnormality. A critical review of the literature suggests that atrial septal defects may occur more frequently than they are reported, and that on occasion they may be described erroneously as patent foramen ovale. The clinical significance of uncomplicated discontinuity of the atrial septum is slight, depending upon the size and location of the defect. Complicated atrial septal defects vary in clinical significance according to the nature of the associated defects.

Animals↗
PubMed1984

Bovine abortion and neonatal death associated with Ureaplasma diversum.

Ureaplasma diversum was isolated from the lungs and/or stomach fluid and placentas of five aborted bovine fetuses and four newborn calves. All isolates were serotype D48. Placentitis was observed in all instances in which the placenta was examined. Gross lesions consisted of focal or diffuse reddening of the chorioallantois and amnion and thickening of the amnion. Microscopically there were fibrosis, edema and inflammation of the amnion. Microscopic lesions in the lung consisted of diffuse pneumonitis with thickening of the alveolar walls and in some cases peribronchiolar lymphoid accumulations. Macrophages and granulocytes were present in the alveoli. Inoculation of the vulva of a virgin heifer with one of the isolates from a fetal lung produced hyperemia and profuse purulent discharge with slight granularity.

Journal Article↗
PubMed1983

The effects of Ureplasma diversum inoculated into the amniotic cavity in cows.

Ureaplasma diversum was inoculated into the amniotic cavity in four cows. Two calves were aborted and two were born alive. One of the latter died shortly after birth and the other was killed. The cows remained clinically normal except that three retained their placenta. On microscopic examination there was a severe placentitis and an alveolitis was present in the lungs of all calves. Ureaplasma was recovered from four placentas and three lungs. Cows remained infected for a maximum of 132 days following inoculation and the organism was recovered in urine and vulvar swabs for a maximum of 17 and 60 days respectively following expulsion of the calf. Ureaplasma diversum has been isolated from natural cases of abortion with similar lesions. This experiment strongly supports a causal relationship between abortion, birth of calves with pneumonia and U. diversum infection.

Journal Article↗
PubMed1982

Replacement of epiphyseal bone with methylmethacrylate: its effect on articular cartilage.

Methylmethacrylate cement was used as a substitute for the epiphyseal bone of the canine proximal femora, after femoral neck osteotomy. The effects of different volumes of acrylic cement on the integrity of trabecular bone and articular cartilage and the effects of different types of fixation of the osteotomy site were assessed clinically, radiologically and histologically. Degenerative changes occurring in the articular cartilage were greatest when a large area of epiphyseal bone was replaced with methylmethacrylate. These degenerative changes varied proportionately with the rigidity of fixation at the osteotomy site. Rigid fixation resulted in a better clinical and radiographic assessment and a decrease in histopathologic changes in the articular cartilage.

Animals↗
PubMed1980

Experimental bovine genital ureaplasmosis. I. Granular vulvitis following vulvar inoculation.

Granular vulvitis was reproduced in ten virgin heifers following vulvar inoculation with strains of ureaplasma previously isolated from natural cases. The disease appeared one to three days postinoculation and was characterized by vulvar swabs but not from the upper mucopurulent discharge. At necropsy 13 to 41 days later, ureaplasmas were recovered consistently from vulvar swabs but not from the upper reproductive tract. It was concluded that some strains of ureaplasma are pathogenic and should be viewed as a cause of bovine granular vulvitis.

Animals↗
PubMed1980

Experimental bovine genital ureaplasmosis. II. Granular vulvitis, endometritis and salpingitis following uterine inoculation.

Twenty-three virgin Holstein heifers received uterine inoculations with ureaplasma and were necropsied one to thirteen days later. Three heifers inoculated intracervically were necropsied on days 3, 5 and 11.Granular vulvitis was produced on average by 3.6 days in fourteen of sixteen uterine inoculated heifers monitored for four or more days. Two cervically inoculated heifers monitored for over four days also developed granular vulvitis by the fourth day. At necropsy, ureaplasma was recovered from 94% of uterine horn cultures for the first four days postinoculation and 50% during days 5 to 7. Thereafter all uterine cultures were negative. The percentage of positive ureaplasma recoveries from uterine tube flushings was lower than for uterine horns but remained positive for a longer period. By day 7, three of four uterine tube flushings were still positive. No bacterial pathogens were isolated from the uterine horns or uterine tube flushings. On histopathology 50% of uterine inoculated heifers had endometritis up to six days postinoculation and a slightly higher percentage (58%) had salpingitis. Endometritis was not found in any heifers after day 6. Residual salpingitis was present in one heifer on day 7. Endometritis was present in cervically inoculated heifers necropsied on days 3 and 5 but not on day 11. Salpingitis was not found in any of the three cervically inoculated animals. The study concluded that some strains of ureaplasma are pathogenic for the upper reproductive tract of the cow and should be considered significant when isolated from cases of granular vulvitis, endometritis or salpingitis.

Animals↗
PubMed1979

Bovine granular vulvitis associated with ureaplasma infection.

A granular vulvitis syndrome associated with ureaplasma infection was first recognized in Ontario dairy herds in 1972. The acute form of the disease was characterized by a purulent vulvar discharge, an inflamed hyperemic vulvar mucosa and varying degrees of granularity. In the chronic form, there was an absence of a purulent discharge and a gradual decline in the severity of the hyperemia and granularity. Epithelial inclusion cysts were observed in the vulvar epithelium of approximately 10% of affected cows.A seasonal variation in the incidence of the disease was observed. Herd morbidities during the summer months reached a low of 37% and increased to 75% during the winter months with constant housing.When widespread in herds, the acute form of the disease had a significant effect on fertility. In four herds examined, first service conceptions dropped on average by 27%. The chronic form of the disease had a less detrimental effect on fertility with first service conceptions being reduced on average by 13%. Intrauterine infusions of a tetracycline 24 hours postbreeding were found to be of value in improving conception rates in acutely affected herds.

Animals↗
PubMed1976

Myodegeneration and suspected selenium/vitamin E deficiency in horses.

The clinical, macroscopic, and microscopic features of 10 isolated cases of myodegeneration in foals were compared. Low values for selenium and vitamin E content were found in the hay and oats from one breeding stable. Serum selenium concentrations in mares at this stable were also low. Creatinine phosphokinase and serum glutamic oxaloacetic transaminase activities were increased in 2 young foals at this stable; in 1 of these foals, both enzymatic activities were markedly reduced after treatment with vitamin E and selenium. Nutritional myodegeneration was suggested as a diagnosis in this stable, on the basis of the histologic findings, feed analyses, serum selenium values, response to treatment, and enzymatic determinations. Nine other isolated cases of nutritional myodegeneration were tentatively diagnosed on the basis of macroscopic and microscopic findings and the young age of the animal. The gross lesions included pale areas in the myocardium and skeletal muscle masses. Histologically, lesions were characterized by fragmentation and hyaline and granular changes in swollen muscle fibers in widely distributed skeletal muscle masses.

Animals↗
PubMedDate not supplied

A comparison of manual and power-assisted thoracolumbar disc fenestration in dogs.

Thoracolumbar disc fenestration was performed in eight canine cadavers. A hole was cut in the anulus fibrosus with a scalpel in four dogs, and with a high speed drill and burr in four dogs. A curette was used to remove as much of the nucleus pulposus as possible. Sixty-five percent of the nucleus pulposus was removed with the power-assisted technique and 41% was removed by manual fenestration. Manual and power-assisted disc fenestration were performed on alternate intervertebral discs from T11-12 to L5-6 in four dogs. Six months after surgery, results of high-detail radiographic and histologic evaluation of the vertebral bodies and discs showed minimal difference in the sequelae of the two techniques. A retrospective medical records analysis and follow-up of 60 clinical cases treated with prophylactic, power-assisted disc fenestration failed to identify any cases with postoperative recurrence of neurologic deficits. Ten percent of the dogs had periodic back pain of unknown etiology, without other signs of intervertebral disc disease. The findings of this study indicate that power-assisted disc fenestration permits more complete evacuation of the nucleus than manual fenestration, causes no more postoperative complications, and results in a low recurrence rate of neurologic deficits.

Animals↗
PubMedDate not supplied

Heterotopic transfer of fresh and cryopreserved autogenous articular cartilage in the horse.

Two 10 mm thick osteochondral grafts were harvested from the lateral aspect of the lateral trochlear ridge of the left talus in each of 10 anesthetized horses. The grafts were frozen in a 7.5% DMSO solution and stored in liquid nitrogen. The horses were anesthetized again on day 14 and the thawed grafts were press-fitted into drill holes in the trochlear ridges of the right stifle. A fresh graft was transferred from the right hock to the left stifle. To control for the effects of surgery, another fresh graft was transferred from the right stifle to the left stifle. The result was two grafts in each femoropatellar joint. Fresh and frozen osteoarticular autografts appeared to maintain a durable weight-bearing surface for 3 months; however, the fresh grafts were clearly superior. Frozen grafts had fewer living chondrocytes, decreased safranin-O staining, and decreased SO435 uptake. Graft stability and articular surface congruency were determining factors in the outcome of all grafts. Since the availability of osteochondral autografts is limited, further work on the use of preserved allogeneic osteochondral tissue is warranted.

Animals↗