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Biomedical subjects

G H Thompson

Publications and source records attributed to G H Thompson.

15 recordsLinked to original sources
PubMed1992

CT during arterial portography: diagnostic pitfalls.

Computed tomography (CT) during arterial portography (CTAP) is an important technique for evaluating the liver before hepatic tumor resection. With this technique, most tumors are of low attenuation compared with that of enhancing parenchyma. At times, low-attenuation lesions are encountered that represent perfusion abnormalities rather than tumor deposits. These perfusion abnormalities can be categorized as (a) those resulting from improper technique; (b) those extending from hilum to capsule (straight-line sign), with or without an obstructing mass; (c) perihilar and periligamentous abnormalities; (d) subcapsular defects (linear or wedge shaped); and (e) those seen with cirrhosis or regenerating nodules. Adjuvant use of delayed CT, magnetic resonance imaging, and intraoperative ultrasound aids in characterization of these nontumorous defects, thereby improving specificity. The authors conclude that when potential candidates are evaluated for hepatic tumor resection, knowledge of the existence of the various diagnostic pitfalls of CTAP and their imaging characteristics is imperative to avoid inadvertent false results.

Angiography, Digital Subtraction↗
PubMed1992

Post-mortem description of slipped capital femoral epiphysis.

We found, in a museum collection of skeletons, nine adult hips with untreated slipped capital femoral epiphyses. All the specimens were from men, five black and two white. Their mean age at death was 44 years. Seven of the femora were retroverted beyond neutral and five had true varus deformities. Osteoarthritis was detected in eight of the hips and the most severe degeneration was seen in the most deformed hips. Radiography revealed that cysts which appeared to occupy the femoral head in fact lay in the metaphyseal bone of the femoral neck.

Adult↗
PubMed1990

Primary neoplasms of the thoracic and lumbar spine. An analysis of 29 consecutive cases.

Primary osseous neoplasms of the thoracic and lumbar spine are uncommon lesions. Between 1965 and 1982, of 1971 patients with musculoskeletal neoplasms, only 29 (1.5%) had primary osseous tumors in these locations. There were eight children and 21 adults. Back pain was the most common complaint in 25 patients (86%), and neurologic symptoms or deficits were present in 16 patients (55%). All lesions were visible on routine spine roentgenograms, while computed tomography and myelography demonstrated spinal canal encroachment and extradural spinal cord compression in 19 patients (66%). The histologic diagnoses included 11 benign and 18 malignant lesions. Benign lesions occurred predominantly in children and malignant tumors in adults. Treatment was individualized, based on the histologic diagnoses. Twenty-two patients had surgical resection of their lesions. Laminectomy without stabilization and arthrodesis resulted in late instability and neurologic deterioration in three of seven patients (43%) with malignant lesions. Resection and decompression combined with arthrodesis did not predispose to late instability. Twenty-one patients were followed for a mean of 4.1 years (range, two to 14 years). Eight patients died from malignant disease between one month and seven years after diagnosis.

Adolescent↗
PubMed1990

Late-onset tibia vara (Blount's disease). Current concepts.

Idiopathic tibia vara or Blount's disease can be classified into three age-onset groups: (1) infantile, less than three years; (2) juvenile, four to ten years; and (3) adolescent, 11 years or older. The latter two groups comprise late-onset tibia vara, which is much less common than the infantile-onset form. In a comparison of eight juvenile-onset patients (13 knees) and seven adolescent-onset patients (nine knees), there were essentially no significant clinical, roentgenographic, or physeal-histopathologic differences. Both groups had severe obesity, mild to moderate varus deformities, and less-pronounced roentgenographic characteristics. Histopathologic analyses of the entire physis from the proximal tibia in five cases (seven knees) were essentially identical in patients with the infantile form as well as in those with slipped-capital femoral epiphyses, suggesting a common etiology. Recurrence of deformity after surgical correction occurred frequently in the juvenile onset males but not in juvenile onset females or the adolescent onset group. Incomplete correction of the varus deformity occurred more frequently in the latter group. The etiology for tibia vara appears to involve varus stress growth suppression, and disruption of endochondral ossification. The major differences between the three groups is due to the age at clinical onset, the amount of remaining growth, and the magnitude of the medial compression forces across the medial aspect of the knee.

Adolescent↗
PubMed1989

Endovaginal and transabdominal sonography of ovarian follicles.

Endovaginal and transabdominal sonography (EVS and TAS, respectively) are effective methods for monitoring ovarian follicular development. Our study evaluates both modalities by subjective comparisons and objective correlations with serum estradiol levels. In 21 of 41 studies, TVS showed more follicles over 1 cm than did TAS. The same number was seen by both in 17 studies and more by TAS in only 3 studies. Margins of the follicles were sharply defined in 37 of 41 EVS studies (90%) but only in 18 of 41 TAS studies (41%). In each of the 4 cases in which follicles were not sharply defined by EVS the ovaries were located high in the pelvis. In 29 sonographic studies, there were corresponding estradiol levels. The number and size of dominant follicles correlated well with estradiol levels (r = .9074) for EVS but less so (r = .3816) for TAS. EVS has several advantages when monitoring follicular development.

Abdomen↗
PubMed1987

Expression of human papillomavirus type 6 E1, E2, L1 and L2 open reading frames in Escherichia coli.

Open reading frame (ORF) fragments (putative gene fragments) from human papillomavirus type 6b (HPV-6b) were inserted into the bacterial expression vector pHK413 to provide viral antigenic determinants. Approximately 86% of the entire L1 ORF, 82% of the E2 ORF, and 52% of the L2 ORF were expressed in Escherichia coli. The E1 ORF was cloned as two fragments. The constructions containing E1n (coding for the N-terminal region) and E1c (coding for the C-terminal region) expressed 27% and 16% of the E1 ORF, respectively. Protein encoded by the L1 ORF, but not that encoded by the L2 ORF, reacted with antibodies elicited by disrupted bovine papillomavirus. These reagents will be extremely useful in unravelling the HPV-6b replication cycle.

Antigens, Viral↗
PubMed1979

Erythromelalgia.

Erythromelalgia is an extraordinary disorder of unknown etiology and pathophysiology that resembles the post-traumatic reflex dystrophy syndromes but has not been described previously in the orthopedic literature. Its distinctive triad of intense burning extremity pain associated with erythema and increased skin temperature are diagnostic. Primary or idiopathic and a secondary or associated form have been identified. The latter occurs in association with an underlying disease process, especially myeloproliferative disorders. Treatment with pharmacologic agents and surgery are ineffective except in the secondary group where treatment of the associated disorder generally results in a remission. Symptoms in the primary group can be minimized by appropriate environmental control with cooling and avoiding heat-producing situations that would raise skin temperature above a critical thermal threshold.

Adolescent↗
PubMed1978

Healed untreated anterior cervical spine dislocation. A case report.

Fracture and fracture-dislocations of the cervical spine are serious injuries that rarely go undiagnosed. A case report of a bilateral facet dislocation with anterior displacement is presented that went undiagnosed and untreated, and healed without neurologic sequelae. No previous similar reports are known.

Aged↗
PubMed1978

A quantitative review of the performance of implanted cardiac pacemakers, Medtronic Model No. 5944.

One of the service functions of the Sir Charles Gairdner Hospital Department of Biophysics since 1972 has been the routine performance testing of pacemakers implanted by the Hospital's Cardiologists. This service was set up to measure pacemaker pulse parameters with a view to detecting battery depletion. It was also found to be of great help in showing lead insulation deterioration, intermittent capture and movement of the catheter tip within the right ventricle, information that is frequently of help to the Cardiologists in planning acute or elective pacemaker replacement.

Electric Conductivity↗
PubMed1977

Vector cardiographic assessment of implanted cardiac pacemakers.

The design and use of an on-line PDP 11/40 based vector cardiographic pacemaker assessment system is described. The system has been designed for comprehensive, automated testing of either fixed rate or demand implanted cardiac pacemakers. It is accurate and can be operated by a laboratory assistant without special training. Pacemaker parameters extracted are pulse height, width, rate, energy index and the frontal plane vector length and angle at maximum inspiration and during quiet breathing. In addition, a graphical representation of the patient's ECG and the pacemaker pulse is obtained on a computer graphics terminal. Patient data are written to cartridge disk for permanent record following the test. At each subsequent test of the implanted pacemaker, the data on disk are addended with the latest quantitative results. A separate off-line FORTRAN program can interrogate disk files for detailed analysis of patient data and display of parameter trends since implantation.

Computers↗
PubMedDate not supplied

Magnetic resonance imaging of an osteoid osteoma of the proximal femur: a potentially confusing appearance.

Osteoid osteomas are common benign pediatric bone tumors. However, radiographic diagnosis and location of the tumor nidus can be difficult. We recently diagnosed and treated an osteoid osteoma of the right proximal femur in a 9-year-old girl in whom the preoperative magnetic resonance images demonstrated a well-marginated lesion in the medullary canal but no tumor nidus. This was confusing and misleading. Correct diagnosis was made with a computed tomography (CT) scan. Care must be taken in interpretation of magnetic resonance imaging (MRI) in disorders in which secondary bone marrow changes occur to avoid erroneous diagnoses and possible incorrect operative procedures.

Child↗
PubMedDate not supplied

Legg-Calvé-Perthes disease: Results of discontinuing treatment in the early reossification phase.

The major controversy in Legg-Calvé-Perthes disease concerns its treatment. All authors recognize the need for containment of the femoral head but do not agree on the method of containment. Surgical containment is constant, does not require an endpoint for discontinuing treatment and has a short treatment period. Conservative treatment, however, produces comparable results, avoids operative and anesthetic complications but requires prolonged immobilization. The concept of Ferguson and Howorth can be validated and indicates that when early subchondral reossification is present on both the anteroposterior and lateral roentgenograms that conservative containment treatment can be safely discontinued thus shortening outpatient time to 12 months or less. The results of 165 hips undergoing conservative treatment and 27 who received surgery are analyzed. Eighty-one conservatively treated hips were mobilized early and followed for an average of 5 years. Their results were identical to those treated until the time of complete restoration of the capital femoral epiphysis. This reduction in outpatient treatment and the decrease in potential complications minimizes several of the major arguments in favor of surgical management.

Age Factors↗
PubMedDate not supplied

Barton's fractures-reverse Barton's fractures. Confusing eponyms.

Anterior and posterior marginal fracture dislocations of the distal radius are unusual injuries, both of which are called Barton's fracture in the current world literature. Barton's original description delineates only the posterior marginal injury. An attempt is made to clarify the nature of these injuries by a complete review of the literature and a study of the clinical experience at UCLA Hospital from 1972 through 1975. Ten anterior and five posterior marginal fractures were treated during that period of time, constituting 2.3 per cent of all distal forearm fractures. Fractures in males typically stemmed from high velocity accidents in the younger age group and were associated with significant additional injuries. The injuries in females resulted from simple falls, generally in the older age group. Eight fractures were treated open and seven closed without complications; treatment results have not been determined yet. Eponym descriptions should be discontinued and replaced with a lucid anatomically descriptive classification such as anterior and posterior marginal fracture-dislocations of the distal radius.

Accidents, Traffic↗