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Biomedical subjects

D Connell

Publications and source records attributed to D Connell.

At least 19 recordsLinked to original sources
PubMed2006

Imaging of the posterolateral corner of the knee.

The structures of the posterolateral corner of the knee are increasingly recognized as fulfilling an important role in maintaining knee stability. The posterolateral aspect of the knee is stabilized by a complex anatomy of osseous, myotendinous and ligamentous structures. Unrecognized injuries to this part of the knee are a cause of failure of cruciate ligament reconstruction. This review focuses on the anatomy and common injury patterns involving the posterolateral corner of the knee, with emphasis on magnetic resonance imaging.

Fractures, Bone↗
PubMed2006

When physiology becomes pathology: the role of magnetic resonance imaging in evaluating bone marrow oedema in the humerus in elite tennis players with an upper limb pain syndrome.

Upper limb stresses are well recognised in tennis, and the normal physiological responses of the humerus to externally applied forces are well defined. Changes to both the microscopic and macroscopic bony architecture are often not apparent on plain radiographs in the early stages of a stress reaction. Bone scintigraphy is more sensitive, but not very specific to subtle changes, as is computer aided tomography. Magnetic resonance imaging (MRI) scans are now used to assess many musculoskeletal injuries, and may allow earlier recognition of changes. This study reports on eight high level tennis players (seven professionals, one highly ranked amateur), who all presented during the course of the 2002 Australian Open and its lead up events. All had an upper limb pain syndrome centred around the elbow. Each underwent an MRI scan. A group of asymptomatic players also had scans of the same area to serve as controls. All symptomatic patients had various levels of bone marrow oedema in their distal humerus, some with periosteal reactions, although most without. No scans revealed a cortical breach. The management of these reactions is problematic in players on an international circuit, as review is sporadic and not always coordinated. The timetabling of international tournaments means it is difficult for top players to obtain adequate rest to avoid injury. Awareness of this early overuse reaction needs to be raised to allow preventive and therapeutic options to be considered to reduce the incidence of this humeral stress response producing an upper limb pain syndrome.

Adolescent↗
PubMed2005

Adhesive capsulitis: sonographic changes in the rotator cuff interval with arthroscopic correlation.

OBJECTIVE: To evaluate the sonographic findings of the rotator interval in patients with clinical evidence of adhesive capsulitis immediately prior to arthroscopy. DESIGN AND PATIENTS: We prospectively compared 30 patients with clinically diagnosed adhesive capsulitis (20 females, 10 males, mean age 50 years) with a control population of 10 normal volunteers and 100 patients with a clinical suspicion of rotator cuff tears. Grey-scale and colour Doppler sonography of the rotator interval were used. RESULTS: Twenty-six patients (87%) demonstrated hypoechoic echotexture and increased vascularity within the rotator interval, all of whom had had symptoms for less than 1 year. Three patients had hypoechoic echotexture but no increase in vascularity, and one patient had a normal sonographic appearance. All patients were shown to have fibrovascular inflammatory soft-tissue changes in the rotator interval at arthroscopy commensurate with adhesive capsulitis. None of the volunteers or the patients with a clinical diagnosis of rotator cuff tear showed such changes. CONCLUSIONS: Sonography can provide an early accurate diagnosis of adhesive capsulitis by assessing the rotator interval for hypoechoic vascular soft tissue.

Adult↗
PubMed2003

Prospective clinical study of autologous chondrocyte implantation and correlation with MRI at three and 12 months.

In order to determine the usefulness of MRI in assessing autologous chondrocyte implantation (ACI) the first 57 patients (81 chondral lesions) with a 12-month review were evaluated clinically and with specialised MRI at three and 12 months. Improvement 12 months after operation was found subjectively (37.6 to 51.9) and in knee function levels (from 85% International Cartilage Repair Society (ICRS) III/IV to 61% I/II). The International Knee Documentation Committee (IKDC) scores showed an initial deterioration at three months (56% IKDC A/B) but marked improvement at 12 months (88% A/B). The MRI at three months showed 82% of patients with at least 50% defect fill, 59% with a normal or nearly normal signal at repair sites, 71% with a mild or no effusion and 80% with a mild or no underlying bone-marrow oedema. These improved at 12 months to 93%, 93%, 94% and 91%, respectively. The overall MR score at 12 months suggested production of normal or nearly normal cartilage in 82%, corresponding to a subjective improvement in 81% of patients and 88% IKDC A/B scores. Second-look surgery and biopsies in 15 patients (22 lesions) showed a moderate correlation of MRI with visual scoring; 70% of biopsies showed hyaline and hyaline-like cartilage. Thus, MRI at 12 months is a reasonable non-invasive means of assessment of ACI.

Adult↗
PubMed2001

Magnetic resonance imaging of the wrist ligaments.

The advent of small arthroscopes has enabled the hand surgeon to visualize the ligaments of the wrist directly with resultant increased accuracy in diagnosing and treating pathology. Orthopaedists are now demanding a preoperative assessment and this, in turn, has necessitated that radiologists have a comprehensive understanding of wrist anatomy. High resolution MR imaging can identify the wrist ligaments reliably and provide information concerning their integrity. Interpretation is not straightforward; there is considerable anatomic variation, and there are perforations, defects and degenerative tears that can be troublesome in diagnosing injury. However, with experience and attention to anatomic detail, the radiologist can provide useful information regarding structural abnormalities. When injured, the ligaments of the wrist behave as other joint ligaments do. Findings following injury include discontinuity of normal striated bands, incomplete disruption, irregularities and alteration in normal signal. Fluid pooling around a ligament and concomitant bone injury are other clues to injury. The identification of such structural abnormalities may help to explain altered biomechanics and improve the management of patients following wrist injury.

Humans↗
PubMed2001

Sonographic examination of lateral epicondylitis.

OBJECTIVE: The purpose of this study was to describe the sonographic appearance of the common extensor origin in cadavers and asymptomatic volunteers, and to relate this appearance to the findings in patients with lateral epicondylitis. SUBJECTS AND METHODS: Seventy-two elbows in 71 patients with lateral epicondylitis were examined on sonography. Most of the patients (60/71) gave a history of repetitive microtrauma. The injuries were evaluated with respect to location and severity. Focal areas of degeneration, discrete cleavage tears, and involvement of the lateral collateral ligament were identified. Calcification and bony changes were noted. The appearance of the normal common extensor tendon was described, and cadaveric specimens were dissected. Twenty-one patients subsequently underwent surgery. RESULTS: The normal common extensor origin is composed of longitudinal fibrils bound closely with the extensor carpi radialis brevis constituting most of the deep fibers, with the extensor digitorum making up the superficial part. The lateral collateral ligament can be identified as a discrete and separate band. The most common appearance of lateral epicondylitis is a focal hypoechoic area in the deep part of the tendon (46/72). These focal areas were identified at surgery and corresponded histologically to collagen degeneration with fibroblastic proliferation. Often discrete cleavage planes traversing the tendon were manifest as partial (18/72) and complete (2/72) tears. The lateral collateral ligament was involved in eight of 72 elbows. CONCLUSION: Sonography of the common extensor origin can be used to confirm lateral epicondylitis in patients with lateral elbow pain and provide information about the severity of the disease.

Adult↗
PubMed1999

A model for non-specific toxicity with aquatic organisms over relatively long periods of exposure time.

Experimental data have shown that the internal lethal concentrations of halobenzenes for aquatic organisms decreased with exposure time. In this paper, a model based on the concept of life expectancy reduction was developed to describe this relationship. The model was verified with experimental data for fish (Gambusia affinis) and juvenile crab (Porturius pelagicus(L)). It is proposed that long term non-specific toxicity can be measured as the reduction of the life expectancy of the exposed organism per unit internal concentration (or volume fraction) of the toxic compound. The model can be used to estimate internal lethal concentration at any given exposure period and vice versa. The model can also be used to estimate chronic values of the internal concentration, of the toxicants. It provides a useful tool for assessment of environmental risk of organic compounds in aquatic ecosystems.

Algorithms↗
PubMed1998

Rationing organs using psychosocial and lifestyle criteria.

The role of patient psychosocial and lifestyle characteristics in decisions about the allocation of scarce health care resources has not been examined. In this national survey using the Criteria for Selection of Transplant Recipient (CSTR) Scale, organ transplant coordinators (N = 559) identified the psychosocial and lifestyle criteria they believe should be considered in patient selection/rejection for organ transplant. Using factor analysis to reduce the data, six factors were identified: current lifestyle/psychiatric problems, family/socioeconomic issues, habits, controlled lifestyle/psychiatric issues, cost, and stigmatized conditions. Patients who were in prison for a serious crime, used cocaine, had AIDS, or were HIV positive (criteria making up the Stigma factor), were more likely to be labeled for exclusion from transplant than those with other psychosocial/lifestyle characteristics. When transplant coordinators perceived that patients' psychosocial and lifestyle problems were under control or corrected, they were more likely to consider them for a transplant. For all but the cost factor, criteria were most stringent for heart transplants. Although over 90% of the coordinators assessed patients and participated in patient selection for transplant, master's prepared nurses were more likely than nurses with other educational preparation to be involved in organ recipient selection. These findings can serve as a prototype for how decisions are made for allocating other scarce health care resources.

Adult↗
PubMed1998

Giant cell tumor of bone with selective metastases to mediastinal lymph nodes.

We report an unusual case of a recurrent giant cell tumor of the patella which presented with metastatic disease to the posterior mediastinal lymph nodes with no evidence of pulmonary metastases. The patient underwent chemotherapy with subsequent successful removal of the mediastinal mass. A review of the reported cases of mediastinal giant cell tumor metastases is provided.

Adult↗
PubMed1997

Internal lethal concentrations of halobenzenes with fish (Gambusia affinis).

The internal lethal concentrations is a potential measure of toxicity which could be usefully applied in environmental toxicology and risk assessment. Using halobenzenes, which are common environmental contaminants, and represented test compounds, experiments were conducted in aquaria with the mosquitofish (Gambusia affinis). The average internal lethal concentration (ILC50) for four representative halohydrocarbons, 1,4-diBB, 1,2,3-triCB, 1,2,4-triBB, and pentaCB, were consistent with those previously observed, i.e., 2.3-8.3 mmol kg-1 fish over exposure time periods of 10.4 to 633 hr. However, the ILC50 for all the compounds is not constant but decreases with increasing exposure time period with a mean first-order rate constant of (4.21 +/- 0.70) x 10-3 hr-1. The time dependency of the ILC50 is inconsistent with the critical internal concentration hypothesis which requires the ILC50 to reach a constant critical value when lethality occurs. The life expectancy of the fish from the beginning of chemical exposure could possibly be related to the ILC50-exposure time relationship.

Animals↗
PubMed1997

Soft tissue osteosarcoma with telangiectatic features: MR imaging findings in two cases.

Extraskeletal osteosarcomas are rare tumors, and the telangiectatic variety is the least common histological variety in this group. This report describes the clinical and MR imaging findings in two cases arising in the pretibial soft tissues. Both tumors demonstrated marked inhomogeneity with T2-weighted spin echo and STIR sequences. One of the tumors revealed numerous fluid levels within the lesion. A review of the MRI features of these tumors is provided. Osteosarcoma with telangiectatic features should be considered in the differential diagnosis of a soft tissue mass with fluid-fluid levels in patients 40 years of age or older.

Aged↗
PubMed1995

The use of in vitro DNA adduct formation to estimate the genotoxicity of residues at contaminated sites.

Genotoxic carcinogens such as polycyclic aromatic hydrocarbons (PAHs) covalently bind to the bases in DNA to form adducts. The formation of DNA adducts is significant with respect to chemical carcinogenesis. Many contaminated sites contain quantities of carcinogens such as PAHs, and the evaluation of the genotoxicity of these soils has important implications for human risk assessment. DNA adducts can be formed using an in vitro system incorporating extracts from contaminated soils. The 32P-postlabelling assay is a sensitive technique for the detection of DNA adducts from complex mixtures of environmental carcinogens. These techniques have been used to form and detect DNA adducts using soils from a number of coal gasworks sites. The results show that the extent of adduct formation depends partially on the petroleum hydrocarbon content of samples, but also on other undetermined factors related to composition. While environmental weathering has been shown to effect the PAH composition of samples, this is not an important factor in controlling the genotoxicity of samples as estimated by DNA adduct formation.

Animals↗
PubMed1994

HIV-related training programs for health care professionals: findings from a collaborative assessment.

Seeking to avoid duplication of effort, evaluators from twelve separate HIV-related training programs worked together to share information, assessment tools, measurement instruments, and preliminary findings across programs. Each training program focused on preparing health care professionals to meet the growing demands of the AIDS epidemic and specifically address psychosocial issues of care. The collaborative effort of program evaluators included an examination of experiences across programs and yielded recommendations for needs assessments, process evaluation procedures, and outcome measures. This paper focuses on the findings from an analysis of needs assessments and process evaluations across twelve HIV-related training programs in eleven areas of the country.

Forecasting↗
PubMed1992

Mechanism and prediction of nonspecific toxicity to fish using bioconcentration characteristics.

A basic theory of nonspecific toxicity has been developed using bioconcentration as a basis and applying kinetic relationships developed in previous work. This approach has involved calculation of the critical volume fraction and critical concentration in lipid tissue of fish for a variety of organic compounds at the lethal level. Corrections to previous data sets for time period of exposure and inclusion of biodegradable compounds did not make a significant improvement in the values obtained. A new data base with compounds containing a wide range of Kow values gave results for critical volume and concentration similar to previous work. The influence of experimental procedures and methods for data development are considered. The basic theoretical derivation developed was found to provide a basis for predicting the approximate nonspecific toxicity of nondegradable lipophilic organic compounds at different exposure time periods. This requires a knowledge of the Kow value and the clearance rate constant (k2) which can be calculated from the Kow value.

Adipose Tissue↗