Search PubMed⌕ Search

Biomedical subjects

S J Morgan

Publications and source records attributed to S J Morgan.

At least 37 records · Page 2Linked to original sources
PubMed1999

Nonunion of a pediatric lateral condyle fracture without ulnar nerve palsy: sixty-year follow-up.

Displaced lateral condyle fractures in the pediatric population are usually treated with open reduction and internal fixation. Significant complications associated with the nonoperative management include nonunion, malunion, deformity, and tardy ulnar nerve palsy. However, few cases of nonunion of the lateral condyle and tardy ulnar nerve palsy with long-term follow-up have been reported. We present a radiographically documented case of a pediatric lateral condyle fracture and subsequent nonunion with significant cubitus valgus deformity without ulnar nerve palsy sixty years following injury.

Aged↗
PubMed1999

Salvage of tibial pilon fractures using fusion of the ankle with a 90 degrees cannulated blade-plate: a preliminary report.

Six patients with ankle joint destruction and delayed metaphyseal union after tibial plafond fracture were surgically treated with tibiotalar arthrodesis and metaphyseal reconstruction, using a fixed-angle cannulated blade-plate. The procedure was performed through a posterior approach in five cases and a lateral approach in one case. The subtalar joint was preserved in all cases. Metaphyseal union and a stable arthrodesis were obtained in all cases without loss of fixation and with no mechanical failure of the blade-plate. Union was obtained in an average of 26 weeks. No secondary procedures were required to obtain union. All six patients were ambulatory at last follow-up. Stable internal fixation for simultaneous tibiotalar fusion and metaphyseal reconstruction can be achieved with a cannulated blade-plate while preserving the subtalar joint in complex plafond fractures.

Adult↗
PubMed1999

Pelvic ring injuries.

Major pelvic disruptions lead to significant problems in acute resuscitation and definitive management. An understanding of the injury--its assessment and treatment principles--are necessary for appropriate management by all orthopaedic surgeons. In this article, we summarize the pelvic ring session at the Southeast Fracture Symposium.

Female↗
PubMed1998

Histological and behavioral protection by (-)-nicotine against quinolinic acid-induced neurodegeneration in the hippocampus.

Injections of quinolinic acid (60, 180, and 600 nmol) in the dorsal hippocampus induced significant neurotoxicity that was evident 1 day after the injection. By day 3, pyramidal as well as granular cells were affected even at the lowest dose of quinolinic acid, an effect that persisted up to 20 days. Consistent with the histological findings, animals with bilateral injections in the dorsal hippocampus were cognitively impaired during acquisition and retention of spatial information in the water maze. A subacute treatment with (-)-nicotine (62 micromol/kg/day) delivered by subcutaneous minipumps prevented the histological and cognitive deficits induced by the bilateral quinolinic acid (60 nmol) injections. These data indicate that quinolinic acid can induce degeneration of both pyramidal as well as granule cells in the hippocampus, leading to cognitive impairments in the rat, and that activation of neuronal nicotinic acetylcholine receptors can prevent the neurodegenerative process induced by quinolinic acid.

Animals↗
PubMed1998

Improved methods for transplanting split-heart neonatal cardiac grafts into the ear pinna of mice and rats.

The rodent heterotopic ear-heart transplant method is a useful alternative to the more technically demanding vascularized graft technique. We modified the procedure to improve efficiency and used it in mice and rats to determine the survival times of both isologous and allogeneic grafts and compare reference immunosuppressants. Bisected rat and mouse cardiac (split-heart) isografts were uniformly viable up to 4 weeks postimplant; however, by 24 weeks only 90% of Lewis rat or C3H mouse split-heart isografts retained electrocardiographic activity, regressing to 81% by 60 weeks for the Lewis rat and to less than 50% for the C3H mouse by 43 weeks post-implant. The potency of tacrolimus, sirolimus, and cyclosporine for prevention of allograft rejection was comparable whether using split-hearts or whole hearts in the Balb/C to C3H mouse model. The maximally effective doses at 2 weeks postimplant for intraperitoneally administered tacrolimus, sirolimus, cyclosporine, and oral leflunomide with Brown-Norway (BN) to Lewis rat ear-split-heart allografts (0.3, 0.1, 3.0, 10, mg/kg/day, respectively) agreed extremely well with published data for the rat primary vascularized heterotopic heart model. This reproducible and efficient transplantation model was improved by using split-hearts to double available donor tissue, a gonadotropin-enhanced breeding strategy that enables routine use of low-fecundity inbred rats as donors, implantation devices that speed and simplify the procedure, and defined electrocardiographic evaluation criteria to maximize sensitivity and provide an objective endpoint for defining rejection.

Animals↗
PubMed1997

Severe reduction in leukocyte adhesion and monocyte extravasation in mice deficient in CC chemokine receptor 2.

CC chemokine receptor 2 (CCR2) is a prominent receptor for the monocyte chemoattractant protein (MCP) group of CC chemokines. Mice generated by gene targeting to lack CCR2 exhibit normal leukocyte rolling but have a pronounced defect in MCP-1-induced leukocyte firm adhesion to microvascular endothelium and reduced leukocyte extravasation. Constitutive macrophage trafficking into the peritoneal cavity was not significantly different between CCR2-deficient and wild-type mice. However, after intraperitoneal thioglycollate injection, the number of peritoneal macrophages in CCR2-deficient mice did not rise above basal levels, whereas in wild-type mice the number of macrophages at 36 h was approximately 3.5 times the basal level. The CCR2-deficient mice showed enhanced early accumulation and delayed clearance of neutrophils and eosinophils. However, by 5 days neutrophils and eosinophils in both CCR2-deficient and wild-type mice had returned to near basal levels, indicating that resolution of this inflammatory response can occur in the absence of macrophage influx and CCR2-mediated activation of the resident peritoneal macrophages. After intravenous injection with yeast beta-glucan, wild-type mice formed numerous large, well-defined granulomas throughout the liver parenchyma, whereas CCR2-deficient mice had much fewer and smaller granulomas. These results demonstrate that CCR2 is a major regulator of induced macrophage trafficking in vivo.

Animals↗
PubMed1997

Pathologic alterations in canine hip dysplasia.

The pathologic changes in articular cartilage appear to be of central importance in the development of canine hip dysplasia. But, articular cartilage has only a limited number of responses to injury and a limited capacity for repair. Damage to articular cartilage in dogs with canine hip dysplasia is likely multifactorial in origin, involving cytokines, abnormal load-bearing, and, possibly, other undefined factors.

Animals↗
PubMed1997

Reliability evaluation of classifying radial head fractures by the system of Mason.

Inter-observer and intra-observer reliability for classifying radial head fractures by the system of Mason was analyzed. Twenty-three cases of isolated radial head fractures and twenty-five sets of corresponding AP and lateral radiographs representing these fractures were assembled. The cases were reviewed and assessed independently according to the system of Mason by twenty practicing orthopedic surgeons. On two occasions, the inter-observer and intra-observer variation was analyzed by standard unweighted Kappa statistics. In both observations, complete agreement was seen in only 16% of the cases. Kappa statistic values indicated that 69% of the cases at first observation and 45% of the cases at second observation suggest moderate to poor agreement. Intra-observer agreement between the first and second observation was graded fair to poor in 60% of the cases. Individual observer consistency was, on average, only 78% (range 60% to 92%). The demonstrated wide degree of variation suggests that the Mason classification is unreliable.

Confidence Intervals↗
PubMed1996

CNS leukemia.

Explore the source record for details and available documents.

Central Nervous System Neoplasms↗
PubMed1993

Characterization of the bovine brain cytosolic phosphatidylinositol 3-kinase complex.

Receptor-linked phosphatidylinositol (PtdIns) 3-kinase may generate a second-messenger signal. Here a large-scale purification of the bovine brain enzyme, based on methods developed by Morgan, Smith and Parker [(1990) Eur. J. Biochem. 191, 761-767] and Fry, Panayotou, Dhand, Ruiz-Larrea, Gout, Nguyen, Courtneidge and Waterfield [(1992) Biochem. J. 288, 383-393] is described. The purified enzyme is shown to be a heterodimer of 85 kDa and 110 kDa protein subunits (p85 and p110). Labelling with 5'-p-fluorosulphonylbenzoyladenosine shows that p110 contains an ATP-binding site and confers catalytic activity to the complex. The purified complex is known to be highly phosphorylated on both p85 alpha and p110 subunits, and dephosphorylation generates a deactivated complex, indicating that phosphorylation is an important covalent modification of the complex and may modulate PtdIns 3-kinase activity.

Adenosine↗
PubMed1993

Comparison of adverse effects of phenylbutazone, flunixin meglumine, and ketoprofen in horses.

The relative toxicity of phenylbutazone, flunixin meglumine, and ketoprofen was studied in healthy adult horses. Sixteen horses were randomly assigned to receive 10 ml of physiologic saline solution, or ketoprofen (2.2 mg/kg of body weight), flunixin meglumine (1.1 mg/kg), or phenylbutazone (4.4 mg/kg) IV, every 8 hours, for 12 days. Results of CBC, serum biochemical analyses, and fecal occult blood tests were monitored. On day 13, all horses were euthanatized and complete necropsy examinations were performed. Mean CBC values remained within normal limits for all groups. Phenylbutazone-treated horses had a significant (P < 0.05) decrease in serum total protein and albumin concentrations. Mean values of all other serum biochemical assays were not different from those of the saline-treated group. Results of all fecal occult blood tests were negative. At necropsy, the glandular portion of the stomach was the area of the gastrointestinal tract most severely affected by phenylbutazone, flunixin meglumine, and ketoprofen. In the phenylbutazone-treated group, but not in the other groups, edema of the small intestine and erosions and ulcers of the large colon were observed. None of the horses treated with saline solution had lesions in the glandular portion of the stomach or in the intestine. Four horses (1/5 and 3/3 in the flunixin- and phenylbutazone-treated groups, respectively) developed renal crest necrosis. Horses in the saline- and ketoprofen-treated groups did not develop renal lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

The pathology of canine hip dysplasia.

Although the complete pathogenesis of cartilage damage in canine hip dysplasia has not been completely worked out, it appears that joint laxity with resultant excessive stresses upon articular cartilage is the initiating factor. Grossly, this damage is characterized by cartilage thinning with potential exposure of subchondral bone, osteophyte formation, and pannus formation. Microscopically, there is a marked variation in chondrocyte cellularity, with focal regions of hypocellularity and chondrocyte clusters and synovial lining cell hyperplasia and hypertrophy as well as a decrease in proteoglycan content. This latter change has been substantiated biomechanically. Ultrastructural studies indicate that there is extensive alteration of collagen organization within the cartilage.

Animals↗
PubMed1992

Radial keratotomy: a review of 300 cases.

Three hundred consecutive cases of radial keratotomy performed between 1985 and 1990 were reviewed. There were no sight threatening complications of surgery and no patient lost one or more lines of corrected Snellen acuity. Overall 78.7% saw 6/12 or better unaided postoperatively and 51.7% saw 6/6 or better. Refraction showed 61.3% to be within 1 dioptre of emmetropia and 86.7% were within 2 dioptres. Further analysis demonstrated that results of unaided acuity and proximity to emmetropia were much better for low (< -2.87 D) and moderate (-3.0 to -5.87 D) than for high (> -6.0 D) myopes.

Adult↗
PubMed1991

Mast cell numbers and staining characteristics in the normal and allergic human conjunctiva.

In this study we report the numbers and metachromatic dye-staining characteristics of mast cells (MCs) in the conjunctiva of normal subjects and patients with seasonal allergic conjunctivitis caused by pollenosis. In addition, we have used a monoclonal antibody to the MC-specific enzyme, tryptase, to enumerate tryptase-positive cells immunohistochemically. Tarsal conjunctival MCs were found to be present in increased numbers in the allergic compared to the nonallergic subjects. Most of the MCs exhibited staining that was formaldehyde resistant, compatible with their identification as connective tissue MCs or basophils. The high positive staining for tryptase confirmed that the metachromatic cells stained with toluidine blue were MCs and not basophils, both in normal and allergic subjects.

Adult↗