Search PubMed⌕ Search

Biomedical subjects

P M Sullivan

Publications and source records attributed to P M Sullivan.

At least 19 recordsLinked to original sources

An apolipoprotein E-based therapeutic improves outcome and reduces Alzheimer's disease pathology following closed head injury: evidence of pharmacogenomic interaction.

Apolipoprotein E (apoE) modifies glial activation and the CNS inflammatory response in an isoform-specific manner. Peptides derived from the receptor-binding region of apoE have been demonstrated to maintain the functional activity of the intact protein, and to improve histological and functional deficits after closed head injury. In the current study, APOE2, APOE3, and APOE4 targeted replacement (TR) mice expressing the human apoE protein isoforms (apoE2, apoE3 and apoE4) were used in a clinically relevant model of closed head injury to assess the interaction between the humanized apoE background and the therapeutic apoE mimetic peptide, apoE(133-149). Treatment with the apoE-mimetic peptide reduced microglial activation and early inflammatory events in all of the targeted replacement animals and was associated with histological and functional improvement in the APOE2TR and APOE3TR animals. Similarly, brain beta amyloid protein (Abeta)(1-42) levels were increased as a function of head injury in all of the targeted replacement mice, while treatment with apoE peptide suppressed Abeta(1-42) levels in the APOE2TR and APOE3TR animals. These results suggest a pharmacogenomic interaction between the therapeutic effects of the apoE mimetic peptide and the human apoE protein isoforms. Furthermore, they suggest that administration of apoE-mimetic peptides may serve as a novel therapeutic strategy for the treatment of acute and chronic neurological disease.

Alzheimer Disease↗

Vitreoretinal surgery after childhood ocular trauma.

AIM: In adults modern vitreoretinal surgery allows many traumatised eyes to be salvaged. However, one third of serious eye injuries occur in the paediatric age group and trauma is a leading cause of monocular blindness in childhood. This study aims to report the indications, complications and outcomes for vitreoretinal surgical intervention after childhood ocular trauma. METHODS: Retrospective case note review of 61 children (age 16 years or less) undergoing vitreoretinal surgical procedures following ocular trauma at a tertiary referral centre. RESULTS: Twenty-eight children (45.9%) had open globe injuries (OGI) and 33 closed globe injuries (CGI, 54.1%). The mean age of children with OGI was 9.5 years and with CGI 12.3 years (P=0.0068). Forty-seven children had traumatic retinal detachments (77.1%), which in 17 cases were treated with conventional scleral buckling surgery and in 30 by vitrectomy. Retinal re-attachment was achieved after one procedure in 70.6% with scleral buckling and 46.7% with vitrectomy. Fourteen children (22.9%) had attached retinas but required vitrectomy for other reasons. After a mean follow-up of 19.6 months, the median visual acuity (VA) of the children improved from counting fingers at presentation to 6/36 at final review (P=0.0031). Traumatic retinal detachment requiring vitrectomy was associated with poor visual outcome (P=0.0003). CONCLUSION: Vitreoretinal intervention resulted in an improvement in vision in 32 children (57.1%) and stabilised 11 at their presenting acuity (19.6%). Two thirds of the children attained a final VA of 6/60 or better. Proliferative vitreoretinopathy was the cause of redetachment in 68.2% of cases and was significantly associated with a poor outcome (P<0.0001).

Adolescent↗

Apolipoprotein E allele-dependent pathogenesis: a model for age-related retinal degeneration.

Age-related macular degeneration (AMD) is a late-onset, multifactorial, neurodegenerative disease of the retina and the leading cause of irreversible vision loss in the elderly in the Western world. We describe here a murine model that combines three known AMD risk factors: advanced age, high fat cholesterol-rich (HF-C) diet, and apolipoprotein E (apoE) genotype. Eyes of aged, targeted replacement mice expressing human apoE2, apoE3, or apoE4 and maintained on a HF-C diet show apoE isoform-dependent pathologies of differential severity. ApoE4 mice are the most severely affected. They develop a constellation of changes that mimic the pathology associated with human AMD. These alterations include diffuse sub-retinal pigment epithelial deposits, drusenoid deposits, thickened Bruch's membrane, and atrophy, hypopigmentation, and hyperpigmentation of the retinal pigment epithelium. In extreme cases, apoE4 mice also develop marked choroidal neovascularization, a hallmark of exudative AMD. Neither age nor HF-C diet alone is sufficient to elicit these changes. We document choroidal neovascularization and other AMD-like ocular pathologies in an animal model that exploits known AMD risk factors. The model is additionally attractive because it is not complicated by invasive experimental intervention. Our findings in this model implicate the human apoE E4 allele as a susceptibility gene for AMD and support the hypothesis that common pathogenic mechanisms may underlie AMD and Alzheimer's disease.

Aging↗

Retinal detachment following surgery for congenital cataract: presentation and outcomes.

AIMS: To review the current management and outcomes of retinal detachment following cataract surgery in childhood. METHODS: A retrospective review of 59 eyes of 52 patients. RESULTS: In 37% of patients, the fellow eye was blind (<3/60). The macula was detached at presentation in 81% of eyes. The detachment was obscured by residual lens matter, or a miotic pupil in 67% of eyes that had cataract surgery before 1970, but in only 30% of eyes operated after 1970. The retina was reattached with one operation in 59% of eyes, and final reattachment was achieved in 81%. No retina was reattached by scleral buckling alone. Visual outcomes were slightly better in eyes that had retinal detachment repair after 1 January 1998. Nine patients were blind in both eyes at the latest follow-up. CONCLUSIONS: Retinal detachment following childhood cataract surgery remains a serious condition. There has been some improvement in the prognosis due to a combination of advances in childhood cataract surgery as well as to improvements in the management of retinal detachment. Early recognition and prompt surgery, using an internal approach, may prevent blindness in most cases.

Adult↗

Total hip arthroplasty with cement and without acetabular bone graft for severe hip dysplasia. A concise follow-up, at a minimum of twenty years, of a previous report.

We previously evaluated a cohort of fifty-three patients with severe hip dysplasia (Crowe Type-II, III, or IV subluxation) who underwent a total of sixty-six Charnley total hip arthroplasties. The acetabular component was placed at the anatomic hip center, the superolateral defect was filled with cement, and no bone-grafting was used to supplement the acetabular wall. All but one patient, who was lost to follow-up, were followed until death or for a minimum of twenty years. Radiographic and functional follow-up data were collected prospectively. This retrospective review included twenty-four patients (thirty-four hips) who were alive at a minimum of twenty years following the surgery. Fourteen (22%) of the sixty-five hips underwent revision of a component, with eleven of the revisions performed because of aseptic loosening. Eight of those eleven hips underwent revision because of acetabular loosening alone; two, because of femoral loosening alone; and one, because of loosening of both components. The combined prevalence of revision because of aseptic loosening of the acetabular component and radiographic evidence of failure of the acetabular component was 28% (eighteen hips). With the numbers available, the need for acetabular revision was not associated with the percentage of cement coverage (p = 0.362) or the Crowe classification (p = 0.159). At a minimum of twenty years postoperatively, the survivorship of the acetabular component was 86% +/- 8% with revision because of aseptic loosening as the end point and 82% +/- 10% with revision because of aseptic loosening or radiographic evidence of loosening as the end point. The results that we evaluated at a minimum of twenty years after use of this technique can be compared with the results of other techniques in studies with similar long-term follow-up periods.

Adult↗

Marked regional differences of brain human apolipoprotein E expression in targeted replacement mice.

We used three human apolipoprotein (apo) E targeted replacement mouse lines, each expressing one of the three common human apoE isoforms to study the pattern of apoE expression in the central nervous system (CNS). Immunocytochemistry on brain sections from all three lines of targeted replacement mice, wild type mice, African green monkeys, and humans show a predominantly glial pattern of apoE expression. The levels of human apoE protein in hippocampus and frontal cortex were similar between targeted replacement mice and non-demented human tissue. Within a given brain region, the levels of apoE were very similar amongst all three isoforms, which contrasts sharply with plasma, where apoE2 levels are 16-fold higher than apoE3 and E4 levels. Across brain regions, cerebellar apoE levels were significantly higher than cerebral apoE levels. In conclusion, we provide detailed analysis of a human apoE animal model system that recapitulates both the pattern and level of apoE expression in non-demented humans. The neurobiology of human apoE isoforms can now be studied in both the normal and post-injury state, since all apoE regulatory sequences are intact. Finally, the differences in apoE levels we observed may explain the regional vulnerability of neuronal degeneration in Alzheimer's disease.

Aged↗

Dislocation after total hip arthroplasty: a single surgeon's experience.

The purpose of this article is to evaluate the dislocations that occurred in a single surgeon practice over a 26 year period. After extensive research, the authors concluded that dislocation continues to occur long after the initial arthroplasty procedure. Patients should be aware that more than a quarter of dislocations occur 2 years following surgery. Use of modular 22 millimeter components were associated with the highest dislocation rate. These components should be used very cautiously. Constrained liners have helped decrease the dislocation rate following revision for dislocation.

Aged↗

Impaction allografting with cement for extensive femoral bone loss in revision hip surgery: a 4- to 8-year follow-up study.

The current study evaluates the 4- to 8-year results of 26 cemented femoral revisions with impaction allografting using a collared femoral component in cases of extensive femoral bone loss. Patients were followed prospectively and were evaluated at an average of 6.0 years after the allograft revision procedure. The average age at the time of surgery was 69.3 years. At final follow-up, 20 patients (20 hips) were living, and 6 patients (6 hips) were deceased. No femoral component rerevisions were performed for any reason in any patient, and none were radiographically loose at final follow-up. There was 1 subsided femoral component of <5 mm, 3 postoperative periprosthetic femoral fractures, and a greater trochanter nonunion rate of 32%. At the current follow-up interval, these cemented femoral revisions with impaction allografting have performed well with excellent clinical and radiographic durability in this difficult patient population. The prevalence of periprosthetic fracture is a significant concern. This study shows durable results using the impaction allografting technique in cases of severe bone loss.

Aged↗

Prevention of dislocation after hip arthroplasty: lessons from long-term followup.

Regarding dislocation after total hip arthroplasty, prevention is worth an ounce of cure. The current authors evaluated dislocation after total hip arthroplasty during the 26-year practice of one surgeon to identify potential variables that can contribute to the prevention of dislocation. Between 1970 and 1996, dislocation after total hip replacement occurred after 7.2% of primary hip arthroplasty procedures (298 of 4164 primary hip replacements) and 11.2% of revision hip arthroplasty procedures (90 of 803 revision hip replacements). Significant findings included an increase in dislocation when 22-mm modular femoral heads were used and a decrease in dislocation after revision for dislocation when constrained liners were used. An additional finding was that 26% of first time dislocations occurred more than 2 years after surgery. Concerning prevention of dislocation, small head modular femoral components should be used cautiously, and constrained liners should be considered in complex revision cases. Patients should be counseled concerning the potential for dislocation many years after their arthroplasty.

Aged↗

The effect of pars plana vitrectomy in the management of Fuchs heterochromic cyclitis.

PURPOSE: Fuchs heterochromic cyclitis (FHC) is characterized by a unilateral chronic iridocyclitis of insidious onset and uncertain cause. Our aim was to evaluate the effect of vitreous surgery in patients with FHC and clinically significant visual symptoms caused by inflammatory vitreous debris. METHODS: This study was a review of 12 eyes of 12 consecutive patients with FHC who underwent pars plana vitrectomy for visually significant vitreous opacities. Cataract extraction with posterior chamber lens implantation had been performed on four eyes preoperatively. Four eyes had a concomitant lensectomy for cataracts, and one had a surgical posterior capsulotomy. Visual and anatomic data were recorded before surgery and for at least 6 months after surgery. RESULTS: Visual acuity improved in all patients from an average logMAR of 0.57 to 0.007 (P = 0.0004) and by more than 2 Snellen lines in 8 of 12 of the eyes (P < 0.05). Symptoms of floaters resolved in all 11 patients in whom they were a symptom. Vitreous haze was cleared completely from an average Nussenblatt grade of 1.7 to 0 after 1 week (P = 0.0001). CONCLUSIONS: Pars plana vitrectomy is a safe and effective treatment for the visual symptoms associated with FHC and can be combined safely with a lensectomy if required.

Adult↗

Revision of a cemented acetabular component to a cementless acetabular component. A ten to fourteen-year follow-up study.

BACKGROUND: Although cementless acetabular components are routinely used in revision hip surgery, few investigators have evaluated the retention and efficacy of these components in the long term. In the current study, the clinical and radiographic outcomes of a series of arthroplasties performed by one surgeon with a cementless acetabular component were assessed at a minimum of ten years. METHODS: From 1986 through 1988, sixty-one consecutive revision total hip arthroplasties were performed in fifty-five patients because of aseptic failure of one or both components of a prosthesis in which both components had been cemented. Twenty-eight patients (thirty-two hips) were alive at a mean of 12.9 years (range, 11.5 to 14.3 years) after the operation. In all of the patients, the acetabular component was revised to a porous-coated Harris-Galante component inserted without cement, and the femoral component was revised to an Iowa component affixed with contemporary cementing techniques. The hips were evaluated clinically and radiographically at a minimum of ten years subsequent to the index revision. No hips were lost to follow-up. RESULTS: None of the acetabular components required revision because of aseptic loosening. Two hips (3%) demonstrated radiographic evidence of aseptic loosening of the acetabular component. The polyethylene liner was exchanged during the follow-up period in eight hips. CONCLUSION: After a minimum of ten years of follow-up, cementless acetabular fixation in revision hip arthroplasty had produced durable results that were markedly better than those reported for acetabular fixation with cement.

Acetabulum↗

The prevalence of disabilities and maltreatment among runaway children.

OBJECTIVE: This research was conducted to determine the prevalence of disabilities among abused and nonabused runaways within a hospital population (Study 1) and community school population (Study 2) and to identify any associations between disability, maltreatment, family stress factors, academic achievement, school attendance, domestic violence and runaway status. METHOD: Descriptive information was collected for maltreated and nonmaltreated runaways from hospital (N = 39,352; 255 runaways) and school (N = 40,211; 562 runaways) populations including: disability status, type of maltreatment, family stress factors, record of domestic violence in the family, academic achievement and attendance. RESULTS: The prevalence rate of disabilities among the maltreated runaways was 83.1% and 47% among the nonmaltreated runaways in the hospital sample and 34% and 17%, respectively, in the school sample. Children and youth with disabilities were at increased risk to become runaways in both populations. The presence of maltreatment significantly increased the association between running away and disability status. Children with behavior disorders, mental retardation, and some type of communication disorder were significantly more likely to run away than children with other disabilities. Among the maltreated runaways with and without disabilities, physical abuse and sexual abuse were significantly associated with running away. Records of domestic violence were more prevalent in the families of runaways with behavior disorders and no diagnosed disability. Lower academic achievement, poor school attendance, and more family stress factors were associated with maltreatment, disability and runaway status. CONCLUSIONS: Children and youth with disabilities are unidentified and unrecognized among runaways. Professionals working with runaways and their families need to be cognizant of the special needs of the population, particularly with respect to behavior disorders, communication disabilities, and mental retardation and reconsider current policy to routinely reunite runaways with their families when running away was precipitated by traumatagenic factors within the family.

Achievement↗

Maltreatment and disabilities: a population-based epidemiological study.

OBJECTIVES: To assess the prevalence of abuse and neglect among a population of children identified as a function of an existing disability, relate specific types of disabilities to specific types of abuse, and to determine the effect of abuse and neglect on academic achievement and attendance rates for children with and without disabilities. METHOD: An electronic merger of school records with Central Registry, Foster Care Review Board, and police databases was followed by a detailed record review of the circumstances of maltreatment. RESULTS: Analyses of the circumstances of maltreatment and the presence of disabilities established a 9% prevalence rate of maltreatment for nondisabled children and a 31% prevalence rate for the disabled children. Thus, the study established a significant association between the presence of an educationally relevant disability and maltreatment. CONCLUSIONS: Children with disabilities are 3.4 times more likely to be maltreated than nondisabled peers. School professionals need to be cognizant of the high base rate of maltreatment among the children they serve. Disability status needs to be considered in national incidence studies of maltreatment.

Adolescent↗

Scleral rupture during retinal detachment surgery: risk factors, management options, and outcomes.

OBJECTIVE: To evaluate the potential risk factors, management strategies, and outcomes of scleral rupture during retinal detachment (RD) surgery. DESIGN: Case-control study. PARTICIPANTS AND CONTROLS: Fourteen consecutive patients with scleral rupture during RD surgery (cases) and 65 consecutive patients who underwent RD surgery without scleral rupture (controls). INTERVENTION: Demographic and clinical data were abstracted from patients' medical records. OUTCOME MEASURES: Visual acuity and retinal attachment status at the last examination. RESULTS: Significant risk factors for scleral rupture during RD surgery were reoperation after failed RD surgery (71 % vs. 32%), and pre-existing scleral pathologic condition (29% vs. none). The site of rupture was in the bed of a previously placed scleral buckle in all patients with a previous buckling surgery. Repair of the rupture included scleral sutures in eight (57%), scleral patch graft in four (29%), and placement of a scleral buckle over the site in two (14%) eyes. Eleven (79%) underwent vitrectomy with retinal tamponade by gas (n = 4) or silicone oil (n = 7). Complications observed postoperatively included vitreoretinal incarceration (n = 3), vitreous hemorrhage (n = 2), suprachoroidal hemorrhage (n = 2) and subretinal hemorrhage (n = 3). In the 14 eyes with scleral rupture, the final visual acuity was > or =20/40 in 1 (7%), 20/50 to 20/200 in 5 (36%), and <20/200 in 8 (57%). Ten (71 %) had proliferative vitreoretinopathy develop. The retina was attached in 7 (50%), 6 (43%) had localized peripheral detachment, and 1 had a total retinal detachment. The vision improved in 4 (29%), was unchanged in 5 (36%), and was worse than before surgery in 5 (36%). In the 65 controls, the visual acuity at the time of the last examination was > or =20/40 in 26 (40%), 20/50 to 20/200 in 21 (32%), and <20/200 in 18 (28%). Sixty three (97%) patients had complete retinal reattachment, 1 (2%) had a localized peripheral RD, and 1 (2%) had an RD involving the posterior pole. After surgery, the vision improved in 45 (69%), was unchanged in 15 (23%), and was worse in 5 (8%) of the control eyes. The visual and anatomic outcomes of the eyes with scleral rupture were significantly worse than in the control group (P = 0.002 and P < 0.001, respectively). CONCLUSIONS: Risk factors associated with intraoperative scleral rupture include reoperation for failed RD surgery and pre-existing scleral pathology. Although this complication may be compatible with a good visual outcome in some patients, a high incidence of persistent or recurrent RD with proliferative vitreoretinopathy worsens the visual outcome for most patients with this complication.

Adult↗

Cemented rotating-platform total knee replacement. A nine to twelve-year follow-up study.

BACKGROUND: Although the LCS (low contact stress) rotating-platform mobile-bearing knee replacement has been used extensively, there have been few intermediate or long-term clinical and radiographic follow-up studies evaluating the device. The purpose of this study was to report the nine to twelve-year results of a consecutive series of patients who had a primary total knee replacement performed with this device. METHODS: Between November 1985 and November 1988, the senior author (R. C. J.) performed 119 consecutive total knee arthroplasties in eighty-six patients with LCS rotating-platform femoral and tibial components and a Townley all-polyethylene dome patellar component. All components were fixed with cement. The average age of the patients at the time of the operation was seventy years (range, thirty-seven to eighty-eight years). Fifty-two patients (seventy-six knees) were female, and thirty-four patients (forty-three knees) were male. The patients were evaluated with clinical knee ratings and radiographic analysis nine to twelve years following the knee replacement. RESULTS: At the time of the nine to twelve-year follow-up, sixty-four patients (eighty-six knees) were alive, eighteen patients (twenty-eight knees) had died, and four patients (five knees) had been lost to follow-up. Of the 114 knees in the eighty-two patients for whom the final outcome was known, none required a reoperation and none had a dislocation of the mobile-bearing prosthesis. For the forty-five patients (sixty-six knees) who returned for final clinical and radiographic follow-up examinations at nine to twelve years, the average clinical and functional Knee Society ratings were 30 points (range, 2 to 70 points) and 44 points (range, 0 to 80 points) preoperatively and 90 points (range, 63 to 102 points) and 75 points (range, 30 to 100 points) at the final follow-up evaluation. The average Hospital for Special Surgery knee rating was 57 points (range, 28 to 80 points) preoperatively and 84 points (range, 59 to 97 points) at the final follow-up evaluation. The average active range of knee flexion was from 0 degrees (range, 0 to 10 degrees) to 102 degrees (range, 15 to 120 degrees) at the final follow-up evaluation. Seven of the sixty-six knees were painful anteriorly. There was no periprosthetic osteolysis and no evidence of loosening on follow-up radiographs. CONCLUSIONS: After nine to twelve years of follow-up, the cemented LCS rotating-platform knee replacement was found to be performing well, with durable clinical and radiographic results.

Adult↗

Time course and cellular localization of inducible nitric oxide synthases expression during cardiac allograft rejection.

BACKGROUND: We have demonstrated that inhibition of inducible nitric oxide synthase (NOS) ameliorated acute cardiac allograft rejection. This study determined the time course and cellular localization of inducible NOS expression during the histologic progression of unmodified acute rat cardiac allograft rejection. METHODS: Tissue from syngeneic (ACI to ACI) and allogeneic (Lewis to ACI) transplants were harvested on postoperative days 3 through 10 and analyzed for inducible NOS mRNA expression (ribonuclease protection assay), inducible NOS enzyme activity (conversion of L-[3H]arginine to nitric oxide and L-[3H]citrulline), and nitric oxide production (serum nitrite/nitrate levels). Inducible NOS mRNA and protein expression were localized using in situ hybridization and immunohistochemistry. RESULTS: Inducible NOS mRNA and enzyme activity were expressed in allografts during mild, moderate, and severe acute rejection (postoperative days 4 through 10), but were not detected in normals, isografts, or allografts before histologic changes of mild acute rejection (postoperative day 3). Inducible NOS expression resulted in increased serum nitrite/nitrate levels during mild and moderate rejection (postoperative days 4 through 6). Inducible NOS mRNA and protein expression localized to infiltrating mononuclear inflammatory cells in allograft tissue sections during all stages of rejection but were not detected in allograft parenchymal cells or in normals or isografts. CONCLUSIONS: Inducible NOS expression and increased nitric oxide production occurred during the early stages of acute rejection, persisted throughout the unmodified rejection process, and localized to infiltrating inflammatory cells but not allograft parenchymal cells during all stages of acute rejection.

Acute Disease↗

Suprachoroidal hemorrhage during pars plana vitrectomy. Risk factors and outcomes.

OBJECTIVE: Suprachoroidal hemorrhage (SCH) is an uncommon but serious complication of pars plana vitrectomy (PPV) that can be associated with a guarded visual prognosis. The purpose of this study is to document the risk factors and outcomes of this complication. DESIGN: Case-control study of consecutive cases of intraoperative SCH occurring during PPV (n = 36) and controls of PPV uncomplicated by SCH (n = 116). MAIN OUTCOME MEASURES: Baseline systemic and ocular characteristics, intraoperative findings, surgical procedures, and final anatomic and visual outcomes were measured. RESULTS: Significant risk factors for the development of SCH during PPV included high myopia (22% of cases vs. 5% of controls), history of retinal detachment (RD) surgery (61% vs. 22%), rhegmatogenous RD (97% vs. 60%), use of cryotherapy (75% vs. 33%), scleral buckling at the time of PPV (50% vs. 19%), external drainage of the subretinal fluid (22% vs. 2%), and intraoperative systemic hypertension. In the 34 SCH cases with 3 months' or more follow-up, the final visual acuity was 20/200 or greater in 11 (32%), count fingers in 5 (15%), hand movement in 7 (21%), light perception in 7 (21%), and no light perception in 4 (12%). In the 106 controls with 3 months' or more follow-up, the final visual acuity was 20/200 or greater in 79 (75%), count fingers in 20 (19%), hand movement in 5 (5%), light perception in 1 (1%), and no light perception in 1 (1%). In the eyes with SCH, 17 (50%) had persistent RD, 10 (33%) had secondary glaucoma develop, and 8 (24%) became hypotonic. The visual and anatomic outcomes of the SCH cases were significantly worse than those in the control group (P < 0.001). The visual outcome was more favorable if the SCH did not extend into the posterior pole (P = 0.002). Attempted intraoperative drainage of SCH was not associated with a better outcome. CONCLUSION: Risk factors for the development of intraoperative SCH during PPV are high myopia, previous RD surgery, rhegmatogenous RD, cryotherapy, scleral buckling, external drainage of subretinal fluid, and intraoperative systemic hypertension. Anatomic and visual outcomes are significantly worsened after this complication.

Case-Control Studies↗