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Biomedical subjects

D G Campbell

Publications and source records attributed to D G Campbell.

At least 19 recordsLinked to original sources

Patellar resurfacing in total knee replacement: a ten-year randomised prospective trial.

A series of 100 consecutive osteoarthritic patients was randomised to undergo total knee replacement using a Miller-Galante II prosthesis, with or without a cemented polyethylene patellar component. Knee function was evaluated using the American Knee Society score, Western Ontario and McMaster University Osteoarthritis index, specific patellofemoral-related questions and radiographic evaluation until the fourth post-operative year, then via questionnaire until ten years post-operatively. A ten-point difference in the American Knee Society score between the two groups was considered a significant change in knee performance, with alpha and beta levels of 0.05. The mean age of the patients in the resurfaced group was 71 years (53 to 88) and in the non-resurfaced group was 73 years (54 to 86). After ten years 22 patients had died, seven were suffering from dementia, three declined further participation and ten were lost to follow-up. Two patients in the non-resurfaced group subsequently had their patellae resurfaced. In the resurfaced group one patient had an arthroscopic lateral release. There was no significant difference between the two treatment groups: both had a similar deterioration of scores with time, and no further patellofemoral complications were observed in either group. We are unable to recommend routine patellar resurfacing in osteoarthritic patients undergoing total knee replacement on the basis of our findings.

Aged↗

Arthrofibrosis following total knee replacement; does therapeutic warfarin make a difference?

Arthrofibrosis following total knee replacement (TKR) is a relatively common complication which results in a reduction in knee range of movement and patient dissatisfaction. A retrospective study examined the relationship between anticoagulation with therapeutic warfarin and rates of arthrofibrosis following TKR. Arthrofibrosis was defined as less than 80 degrees of knee flexion 6-8 weeks post-TKR. Patients were warfarinised if they had a history of thrombophilic tendencies or medical conditions necessitating anti-coagulation, rather than as routine thromboprophylaxis. All other patients received thromboprophylaxis using low molecular weight heparin. A total of 728 patients underwent 874 primary TKR between 1993 and 2002 in one centre, performed by four surgeons. Mean age was 68 years (range 48-89 years) and there were 483 female and 391 male knees. Eighty cases were warfarinised post-operatively (53 female, 27 male). Overall, 83 of 874 TKRs (9%) had arthrofibrosis (57 female, 26 male) requiring manipulation under anaesthetic (MUA). In the warfarinised group, 21 knees (26%) had an MUA (15 female, 6 male). This compared to 62 cases (8%) requiring MUA in the non-warfarinised group (42 female, 20 male). There was a statistically significant difference on Fisher's exact testing (P<0.0001) between groups. Following MUA, knee flexion improved in 95% cases to a minimum 95 degrees but 8 cases had a fixed flexion deformity of 5-10 degrees . In conclusion, therapeutic warfarinisation post-TKR leads to a statistically greater chance of the patient developing arthrofibrosis compared to prophylactic low molecular weight heparin and that patients should be counseled appropriately.

Aged↗

Patient-perceived outcome measures following unicompartmental knee arthroplasty with mini-incision.

We reviewed 150 patients (183 knees) who underwent mini-incision unicompartmental knee arthroplasty (Oxford). Mean age was 71.5 (36-92) years. Review was conducted at least 12 months following surgery. To assess results, we used the Oxford knee questionnaire, modified Grimby score, return to sport and work, knee "normality" and patient general health. The mean Oxford knee score was 22.17 (range 12-54). Kneeling scored worse than other activities. No significant age or gender difference was found. Mean modified Grimby score was 3.89, equating to moderate exercise less than 2 h a week. Patients with "artificial-feeling" knees had significantly worse scores than patients with normal/near-normal-feeling knees. Patients who returned to/increased sporting activity had better Oxford scores than those who did not. Ninety-four percent of patients working pre-operatively returned to work. Sixty-seven percent continued at the same level of or increased sporting activity. Oxford knee scores and return to sport compared well to published data. Results regarding modified Grimby score, return to work and pain relief were encouraging. The best results were achieved in active patients who felt their health was good and their knee felt normal or near normal following surgery.

Adult↗

Reliability of acetabular bone defect classification systems in revision total hip arthroplasty.

Three classifications for assessment of acetabular bone loss were evaluated for their reliability. The 3 systems assessed were the system described by Gross, the system described by Paprosky, and the classification of the American Academy of Orthopaedic Surgeons. In this study, we assessed their reliability based on the preoperative radiographs alone. Intraobserver agreement was measured by evaluating the classifications by the 3 innovators, 3 reconstructive orthopaedic surgeons, and 3 residents. Interobserver agreement was assessed among the reconstructive surgeons and the residents. The unweighted kappa statistic was used to establish levels of agreement. The innovators had better intraobserver agreement than the other 2 groups. Their agreement was only in the moderate range, however. For the noninnovators, intraobserver and interobserver agreement generally was poor for all 3 classifications assessed. Our results indicate that these classifications do not provide statistically reliable information for preoperative assessment of acetabular bone stock loss.

Acetabulum↗

Sociotropy and autonomy: preliminary evidence for construct validity using TAT narratives.

In this investigation, we evaluated the construct validity of sociotropy and autonomy as assessed by the revised Personal Style Inventory (PSI; Robins et al., 1994). Stories given to 6 cards of the Thematic Apperception Test (Murray, 1943) were coded for need for Achievement (McClelland, Atkinson, Clark, & Lowell, 1953) and need for Affiliation (Heyns, Veroff, & Atkinson, 1958). These scores were correlated with PSI Sociotropy and Autonomy, along with their component subscales. The construct validity of Sociotropy, Autonomy, and 5 of 6 component subscales were supported as hypoth sized. Consistent with past research, there was no support for the construct validity of the Perfectionism/Self-Criticism subscale of Autonomy. In addition, separate analyses by gender suggested that the construct validity of sociotropy may be greater for women than for men. The results represent an important finding in that nonquestionnaire measures of interpersonal and achievement-related concerns were found to support the validity of the PSI, a need identified by the questionnaire's authors.

Adolescent↗

Identification of pleckstrin-homology-domain-containing proteins with novel phosphoinositide-binding specificities.

The second messenger phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P(3)] is generated by the action of phosphoinositide 3-kinase (PI 3-kinase), and regulates a plethora of cellular processes. An approach for dissecting the mechanisms by which these processes are regulated is to identify proteins that interact specifically with PtdIns(3,4,5)P(3). The pleckstrin homology (PH) domain has become recognized as the specialized module used by many proteins to interact with PtdIns(3,4,5)P(3). Recent work has led to the identification of a putative phosphatidylinositol 3,4,5-trisphosphate-binding motif (PPBM) at the N-terminal regions of PH domains that interact with this lipid. We have searched expressed sequence tag databases for novel proteins containing PH domains possessing a PPBM. Surprisingly, many of the PH domains that we identified do not bind PtdIns(3,4,5)P(3), but instead possess unexpected and novel phosphoinositide-binding specificities in vitro. These include proteins possessing PH domains that interact specifically with PtdIns(3,4)P(2) [TAPP1 (tandem PH-domain-containing protein-1) and TAPP2], PtdIns4P [FAPP1 (phosphatidylinositol-four-phosphate adaptor protein-1)], PtdIns3P [PEPP1 (phosphatidylinositol-three-phosphate-binding PH-domain protein-1) and AtPH1] and PtdIns(3,5)P(2) (centaurin-beta2). We have also identified two related homologues of PEPP1, termed PEPP2 and PEPP3, that may also interact with PtdIns3P. This study lays the foundation for future work to establish the phospholipid-binding specificities of these proteins in vivo, and their physiological role(s).

Amino Acid Motifs↗

Posterior capsule rupture after a paint-pellet injury.

We report a case in which a high-velocity paint pellet injury to the eye ruptured the posterior lens capsule. In the setting of blunt trauma, posterior capsule rupture has rarely been reported. Recognizing such a rupture allows the surgeon to plan the best surgical approach.

Adolescent↗

Sterilization of HIV with irradiation: relevance to infected bone allografts.

BACKGROUND: Bone allograft banks commonly sterilize frozen bone by irradiation. The dose-response relationship for HIV is calculated and the dose required to inactivate the bioburden of virus that may be present in allograft bone is determined. METHODS: A virus titre experiment is performed using irradiated frozen HIV. The virus is maintained on dry ice (approximately -70 degrees C) and is exposed to a cobalt 60 source with 0-40 kGy irradiation at 5 kGy intervals. Lymphocyte cell cultures are exposed to serial dilutions of the irradiated virus. The virus titre is quantified by cytological changes of HIV infection and p24 immunofluorescence. RESULTS: There is a linear relationship between the virus titre and the radiation dose delivered. The inactivation rate of irradiated virus was 0.1134 log10 tissue culture infective doses 50/mL per kGy (95% confidence intervals, 0.1248-0.1020). The irradiation dose required to inactivate the HIV bioburden in allograft bone is 35 kGy. The irradiation dose required to achieve a sterility assurance level of 10(-6) is 89 kGy. This dose exceeds current recommendations for sterilizing medical products and the current practice of many bone banks. CONCLUSIONS: It is concluded that gamma irradiation should be disregarded as a significant virus inactivation method for bone allografts.

Bone Transplantation↗

Seven specialized exposures for revision hip and knee replacement.

With the increasing rates and complexity of revision hip and knee arthroplasty, it has become more important than ever to approach the joint in a safe and rational manner. The development of extensile approaches have significantly simplified the removal of solidly fixed components without compromising bone stock. The extended trochanteric osteotomy enables controlled access to the femoral component and is a useful technique for revision of solidly-fixed femoral components. The trochanteric slide allows comprehensive exposure of the acetabulum and femur comparable to trochanteric osteotomy with a diminished risk of trochanteric escape. The vastus slide allows wide exposure of the femoral shaft when using an anterolateral approach. In revision total knee arthroplasty, the extensor mechanism is often at risk of disruption or avulsion, and in most cases, maneuvers that allow wide exposure of the femur and tibia while preserving the extensor mechanism are essential. Such exposures include one of the extensor mechanism reflecting techniques either proximally by rectus snip or patellar turndown, or distally by tibial tubercle osteotomy. Occasionally a femoral peel or epicondylar osteotomy is required. There should be a low threshold to consider one of these specialized approaches during revision hip and knee arthroplasty.

Acetabulum↗

Ocular bubble formation as a method of assessing decompression stress.

Tear film bubble formation and ultrasound reflectivity of the lens-vitreous humor compartments were monitored following simulated dives in a hyperbaric chamber. the sensitivity of these methods in determining decompression stress was compared with the results of precordial Doppler ultrasound. In addition, the utility of these diagnostic techniques in testing decompression dive profiles was evaluated. Eleven divers completed two series of chamber dives according to the decompression schedule of the Professional Association of Diving Instructors. The first dive series comprised dives to 70 feet of seawater (fsw) for 15, 29, and 40 min. The second series comprised maximum duration no-stop decompression dives to 40 fsw for 140 min, 70 fsw for 40 min, 90 fsw for 25 min, and 120 fsw for 13 min. Before and immediately after each dive, the following measurements were obtained from each subject: eye surface tear film bubble counts with a slit-lamp microscope, lens and vitreous humor reflectivity using A- and B-mode ophthalmic ultrasonic scan, and precordial Doppler ultrasonic detection of venous gas bubbles. Tear film bubble assessment and ocular scanning ultrasound were observed to be more sensitive in detecting decompression stress than the conventional Doppler ultrasonic surveillance of the precordial region. In contrast to precordial Doppler ultrasonic surveillance, which failed to detect any significant changes in circulating bubbles, tear film bubble formation displayed a dose-response relationship with increasing duration of the 70-fsw dives. Reflectivity changes of the lens-vitreous humor interface were not significant until the no-stop decompression limit was reached. In addition, for each of the no-stop decompression limit dives, increases in the average tear film bubble formation and lens-vitreous humor interface reflectivity were similar. Ocular bubble observations may provide a practical and objective ocular bubble index for analyzing existing decompression schedules and predicting individual susceptibility to decompression sickness.

Adolescent↗

Delayed hyphema and intravitreal blood following intrableb autologous blood injection after trabeculectomy.

PURPOSE: To report delayed hyphema and intravitreal blood as complications following intrableb autologous blood injection after trabeculectomy. METHODS: Case report. A 44-year-old woman with hypotony and maculopathy after trabeculectomy with mitomycin C received an intrableb autologous blood injection. RESULTS: Three days after the blood injection, a hyphema formed and subsequently dispersed into the vitreous. CONCLUSIONS: Although immediate hyphema from autologous blood injection is common, hyphema may be delayed and associated with intravitreal blood.

Adult↗

Cloning and expression of cystolic phospholipase A2 (cPLA2) and a naturally occurring variant. Phosphorylation of Ser505 of recombinant cPLA2 by p42 mitogen-activated protein kinase results in an increase in specific activity.

Full-length cytosolic phospholipase A2 (cPLA2) was cloned from U937 cells and polymorphonuclear leukocytes (PMNLs) while a naturally occurring variant of cPLA2, which lacks residues Val473-Ala749 but has a C-terminal extension of ILMNLSEYMLWMSKVKRFM (DcPLA2) was cloned from PMNLs and mononuclear leukocytes. We were unable to clone DcPLA2 from U937 cells. When cPLA2 and DcPLA2 were expressed in insect cells, both proteins were detected in cell lysates by SDS/PAGE as single bands of apparent molecular masses 100 kDa and 57 kDa, respectively. Full-length cPLA2 was phosphorylated stoichiometrically by p42 mitogen-activated protein (MAP) kinase in vitro at a similar rate to other physiological substrates of this protein kinase and the major site of phosphorylation was identified by amino acid sequencing as Ser505. [32P]Ser(P)505 in cPLA2 was only dephosphorylated at a slow rate by mammalian tissue homogenates. Protein phosphatases 2A, 2B and 2C all contributed significantly to the overall dephosphorylation of cPLA2. The phosphorylation of cPLA2 by p42 MAP kinase correlated with an approximately 1.5-fold increase in specific enzyme activity which was reversed by dephosphorylation.

Amino Acid Sequence↗

The autism survey: an evaluation of reliability and validity.

Psychometric properties of the Autism Survey, an instrument designed to assess respondents' knowledge about autism, were evaluated. Subjects completed the survey at a training conference and again 1 month later. Confirmatory factor analysis indicated that the survey measures one factor. With respect to reliability, the Autism Survey proved to be stable across time, and the total score was internally consistent. A few rogue items were recommended for deletion. Further analyses support the validity of the instrument.

Autistic Disorder↗

Modulation of kinin outflow from isolated perfused rat hearts by endothelin-1.

Bradykinin has previously been shown to suppress ET-1 secretion by endothelial cells. In the present study, rat isolated hearts have been perfused with Krebs solution using the Langendorff method. Immunoreactive bradykinin (IRBK) was measured in the perfusate and the basal level was found to be constant for up to 3 h. Ten min perfusions of the hearts with ET-1 at concentrations of 0.2-20 pM produced a dose-related suppression of kinin outflow by over 90% (P < 0.05). At these concentrations ET-1 had no detectable effect on the coronary vasculature or ECG. At 200 pM ET-1 and above, the hearts showed arrhythmias of increasing severity, accompanied at the highest doses by marked coronary constriction and an increase in IRBK outflow.

Animals↗

Dynamic changes in circulating and antigen-responsive T-cell subpopulations post-Mycobacterium bovis infection in cattle.

Bovine tuberculosis is a threat to animal and human health in several countries. Greater understanding of the immunology of the disease is required to develop improved tests and vaccines. This study has used a model of bovine tuberculosis, established in the natural host, to investigate the dynamic changes that occur in the circulating T-cell subpopulations after infection. When the phenotypic composition of the peripheral blood lymphocytes was determined pre- and post-experimental infection, the response to disease comprised three phases. Firstly, the WC1/gamma delta T cells decreased and then increased, suggesting localization to developing lesions and clonal expansion. Secondly, the CD4:CD8 ratio increased. Thirdly, the CD4:CD8 ratio decreased to less than pre-infection measurements. The latter changes suggested sequential involvement of CD4 and then CD8 T cells. The proportion of cells expressing interleukin-2 receptor (IL-2R) also increased. Panels of T-cell clones were established at various stages post-infection and all clones that exhibited antigen responsiveness were phenotyped. T-cell clones from early infection were WC1/gamma delta and CD4 in phenotype, while CD8 clones appeared later in infection, eventually becoming dominant. Therefore, from in vivo and in vitro evidence, it was suggested that there is a dynamic progression in the T-cell subpopulations involved dominantly in responses to mycobacteria.

Animals↗