Biomedical subjects
G H Thompson
Publications and source records attributed to G H Thompson.
Magnetic resonance imaging after arterial portography with manganese dipyridoxal diphosphate.
RATIONALE AND OBJECTIVES: The authors assess performing hepatic magnetic resonance imaging (MRI) after arterial portography with manganese dipyridoxal diphosphate (MnD-PDP), a hepatobiliary contrast agent, as an invasive but potentially highly sensitive means of focal lesion detection. METHODS: Eight pigs underwent superior mesenteric artery catheterization and injection of 10 mumol/kg MnDPDP. Magnetic resonance imaging at 1.5 T (SE-140/10) was performed before, then at 15 and 30 minutes after injection. Seven or more days later, the same MRI protocol was performed after intravenous injection of 10 mumol/kg MnDPDP. RESULTS: Fifteen minutes after intra-arterial injection, enhancement of the liver predominated (86 +/- 13%), followed by the renal cortex (44 +/- 14%), pancreas (26 +/- 9%), and spleen (14 +/- 9%). At 30 minutes, enhancement of renal cortex significantly increased (50 +/- 14%). There was no significant difference in enhancement of the liver, spleen, pancreas, or renal cortex when we compared intra-arterial and intravenous administration. CONCLUSION: After the injection of 10 mumol/kg MnDPDP into the superior mesenteric artery of pigs there is no significant difference in visceral organ enhancement compared to intravenous administration. The data suggests that the hepatocyte binding sites may be overwhelmed by this dose and/or injection rate of MnDPDP.
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.
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.
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.
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.
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.
Anterior and posterior marginal fracture-dislocations of the distal radius. An analysis of the results of treatment.
Anterior and posterior marginal fractures of the distal end of the radius associated with dislocation of the carpus are rare injuries. The results of 20 patients with 12 anterior and eight posterior marginal fracture-dislocations of the distal radius were reviewed. Eleven patients had closed reduction and plaster cast immobilization, including three with external fixation, while nine patients required surgery and internal fixation. At a mean of 3.2 years, 40% were rated as excellent, 45% as good, 5% as fair, and 10% as poor. There was roentgenographic evidence of posttraumatic arthritis in 13 patients (65%). Major factors affecting the clinical results were accurate articular realignment and the presence of ipsilateral carpal injuries. There were no significant differences in results between anterior and posterior marginal fractures or between closed or operative methods of treatment when the radiocarpal articular surface was restored to less than 1 mm residual displacement. Restoration of articular congruency is the primary goal of management of these fractures.
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.
Legg-Calvé-Perthes disease. Current concepts and controversies.
Legg-Calvé-Perthes disease is a common, controversial pediatric hip disorder. It is currently accepted that the disorder represents idiopathic avascular necrosis (osteonecrosis) of the capital femoral epiphysis. Treatment by conservative or surgical containment is recommended primarily for older children with extensive femoral head involvement. The results of containment treatment indicate improved results over the natural history of the disease process.
Deformity after premature closure of the distal radial physis following a torus fracture with a physeal compression injury. Report of a case.
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Ewing sarcoma of the proximal phalanx of a finger. A case report.
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Achilles tendon rupture. Occurrence with a closed ankle fracture.
A 61-year-old man, involved in an automobile accident, sustained a complete Achilles tendon rupture with an ipsilateral, closed slightly displaced medial malleolus ankle fracture. The tendon rupture was not diagnosed before operation but was recognized at the time of open reduction of the ankle. This rare combination of injuries was apparently secondary to hyperdorsiflexion of the foot. The tendon rupture would have been missed had surgical treatment not been required. Unrecognized tendon ruptures associated with closed ankle fractures may be a cause of residual ankle-foot weakness, pain, loss of motion, or a combination thereof.
Segmental spinal instrumentation in idiopathic scoliosis. A preliminary report.
Eighty-six patients with idiopathic scoliosis who underwent a posterior spinal fusion using sublaminar segmental spinal instrumentation were analyzed retrospectively. There were two operative groups: group 1, 66 patients who had Harrington rod instrumentation and segmental wiring, and group 2, 20 patients who had Luque rod instrumentation. The clinical and radiographic data of the two groups were similar except for the passage of more sublaminar wires and increased intraoperative blood loss in group 2. Twenty intraoperative or postoperative complications occurred in 19 patients (22%) including 14 neurologic complications. Three patients (3%) had major spinal cord injuries, while 11 patients (13%) had transient sensory changes. There was no significant difference in the incidence of neurologic complications between group 1 or group 2. The remaining intraoperative complications were due either to anesthesia, positioning during surgery, or technique (dural tear). Late complications occurred in two patients in group 1 only: one each with rod breakage and hook displacement. Only one patient (1%) has required additional surgery. Our results indicate that although segmental instrumentation can be beneficial in idiopathic scoliosis, the incidence of complications, primarily neurologic, will be higher than expected. The major reason appears to be surgeon inexperience with passage of sublaminar wires. As experience increases, the incidence of complications declines and becomes comparable with conventional Harrington rod instrumentation alone.
Comprehensive management of arthrogryposis multiplex congenita.
Arthrogryposis multiplex congenita syndrome, characterized by multiple congenital joint contractures, is a manifestation of a neurogenic or myopathic disorder of unknown etiology. An accurate diagnosis is critical in management strategy. Muscle biopsy is usually the most important diagnostic procedure. Once the diagnosis is established, a team approach to comprehensive care is instituted, and the child is assisted in achieving maximum cognitive, physical, and social development. Physicians, nurse clinicians, therapists, social workers, and others constitute the team and work in coordination to develop an individual habilitation plan. The treatment plan is continually updated and modified as needed. Because the musculoskeletal deformities are generally the most prominent abnormality, the orthopedist usually has the major role in management. The orthopedist may serve as coordinator of the comprehensive care team and therefore must have a fundamental understanding of and global approach to management.
Proximal tibial epiphyseal fracture in an infant.
Proximal tibial epiphyseal fractures are rare injuries occurring predominantly in older children and adolescents. They have not previously been reported in infants. The present case is that of a 7-month-old female infant with a displaced Salter-Harris type II fracture secondary to child abuse. This represents the youngest documented case of a proximal tibial epiphyseal fracture. Open reduction and internal fixation were performed because of failure to obtain an anatomic alignment by closed reduction. The anatomic reason for unsuccessful closed reduction intraoperatively was found to be an infolding of the pes anserinus and periosteum. Tibia valga occurred postoperatively because of asymmetrical physeal overgrowth and required corrective osteotomy.
Late-onset tibia vara: a comparative analysis.
We reviewed the clinical and radiographic characteristics and response to treatment of 11 children (16 knees) with idiopathic late-onset tibia vara (adolescent Blount's disease) followed for an average of 5.7 years (range, 3-10 years). The clinical characteristics were very consistent: black race; 2:1 male predominance; normal height; marked obesity; knee pain as the primary presenting complaint; and slowly progressive genu varum deformity that averaged 19 degrees (range, 10-45 degrees). Radiographically, the epiphyses were wedge shaped owing to medial flattening, the physes were irregular in thickness, and there was minimal, if any increased prominence of the proximal medial metaphysis. Nineteen proximal tibial valgus and diaphyseal fibula osteotomies were performed on 15 knees. There was a 50% rate of recurrent deformity in males with clinical onset at less than or equal to 10 years of age. Females and older males had no recurrences. Histopathologic studies of the physis performed on one case demonstrated abnormal cellular islands of hyaline cartilage, small foci of necrotic cartilage, prominent intertrabecular vascularity, and premature medial physeal closure. These data support late-onset tibia vara as a distinct entity closely related to the infantile form. They also suggest three specific forms of tibia vara based on the age at clinical onset: infantile (0-3 years), juvenile (4-10 years), and true adolescent (11 years or older). The juvenile group is characterized by a high rate of recurrence following surgical correction, whereas the others are not.