Biomedical subjects

J L Marsh

Publications and source records attributed to J L Marsh.

At least 19 recordsLinked to original sources

PubMed1992

Human dopa decarboxylase: localization to human chromosome 7p11 and characterization of hepatic cDNAs.

We have cloned full-length DDC cDNAs from a human hepatoma cDNA library [DDC; dopa decarboxylase; aromatic-L-amino acid decarboxylase, EC 4.1.1.28]. The protein encoded by hepatoma cells is the same as that encoded by adrenal chromaffin derived pheochromocytoma cells, despite reported differences in biochemical properties. We have confirmed the location of the DDC gene to chromosome 7 using a new panel of somatic cell hybrids, and we have localized the gene to band p11 on chromosome 7 by fluorescent in situ hybridization. The human gene retains 65% amino acid identity with Drosophila DDC (Accession No. X04426) and considerable structural similarity with other enzymes (F.R. Jackson, 1990, J. Mol. Evol. 31:325-329, and references therein).

Animals↗

PubMed1992

Dynamic external fixation for stabilization of nonunions.

Twenty-five long-bone nonunions were stabilized until healing with a dynamic axial fixator (DAF). Seventeen cases were culture positive and ten had open draining wounds. Five cases had segmental gaps larger than 3 cm. In addition to the DAF, infected atrophic cases received debridement, coverage, and bone graft. Cases with segmental gaps were usually treated with massive posterolateral grafts to create a tibiofibular synostosis. Hypertrophic cases received only compression and weight bearing. Bone grafts were performed in 14 cases. The DAF was usually removed after 16-24 weeks of treatment. Twenty of the twenty-five cases were healed at DAF removal and required no further intervention. Nine of the ten hypertrophic cases healed in an average of 18.1 weeks without graft. Thirteen of 15 atrophic cases were bone grafted. Cases with segmental gaps larger than 3 cm were treated with prolonged external fixation to protect maturing grafts, but were still subject to stress fracture after fixator removal.

Adult↗

PubMed1991

Unilateral external fixation until healing with the dynamic axial fixator for severe open tibial fractures.

One hundred one cases of open tibia fractures were treated until healing with a unilateral external fixation device that permits fracture site compression with weight bearing. There were 38 type II and 63 type III (24 IIIA, 33 IIIB, six IIIC) open fractures. A standard protocol was followed including irrigation and debridement and, when necessary, flap coverage (19 cases) and bone grafting (31 cases). Fixators were applied at the first debridement and removed when the fracture was healed. All patients were permitted early partial weight bearing and progressed to full weight bearing with fixator dynamization. Ninety-six cases healed in the fixator (12-50 weeks; average, 24.6). Three of the five failures were associated with screw complications. Five patients required screw changes and 29 required oral antibiotic therapy for screw complications. Ninety-five percent of healed cases had angulation of less than 10 degrees (in any plane). There were only six fracture site infections during the course of treatment. Dynamic axial fixation may be applied at the first debridement and be used until healing in severe open tibia fractures. Change of the fixator to another treatment method is not required.

Adolescent↗

PubMed1991

Calcaneal insufficiency avulsion fractures in patients with diabetes mellitus.

Radiographs and clinical records of 61 patients with calcaneal fractures were studied. Twenty-one patients had diabetes mellitus, and 40 were nondiabetic. All diabetic patients were insulin dependent for more than 5 years and had clinically evident peripheral neuropathy. Eighteen of the diabetic patients had no history of significant trauma. Fourteen had calcaneal insufficiency avulsion (CIA) fractures limited to the posterior third of the calcaneus. The fracture pattern in this group occurred in the same plane as a fatigue-type calcaneal fracture. Fragments of the posterior tuberosity were usually displaced 10-30 mm and were frequently rotated. The mean time from diagnosis of diabetes mellitus to CIA fracture was 20 years. Fractures in the nondiabetic group and in the three diabetic patients with a history of trauma did not resemble the CIA pattern. In the nondiabetic group, there were no insufficiency fractures; 39 fractures occurred with significant force (eg, motor vehicle accident or fall from height), and 33 had extension to subtalar or calcaneocuboid joints.

Adult↗

PubMed1991

Postoperative bone marrow alterations: potential pitfalls in the diagnosis of osteomyelitis with In-111-labeled leukocyte scintigraphy.

Scintigraphy was used after injection of technetium-99m methylene diphosphonate (MDP) and indium-111-labeled white blood cells (WBCs) to assess for the presence of osteomyelitis in 97 patients who had undergone prior surgical procedures. Thirty-four patients with abnormal In-111-labeled WBC patterns underwent restudy with Tc-99m albumin colloid (AC). Scintigraphic findings were considered positive for osteomyelitis whenever localization of In-111-labeled WBCs exceeded Tc-99m AC activity in extent or focal intensity (discordant pattern). Ten of 12 patients with culture-proved osteomyelitis had discordant patterns; two had false-negative (concordant) patterns. The cases of 20 of 22 patients without infection who were considered to have osteomyelitis on the basis of patterns of In-111-labeled WBCs and Tc-99m MDP were reclassified correctly on the basis of concordant patterns of In-111-labeled WBCs and Tc-99m AC. Radiocolloid images improved the overall scintigraphic specificity for osteomyelitis from 59% without bone marrow imaging to 92%; sensitivity decreased from 94% to 88%.

Adolescent↗

PubMed1991

Growth of the cranial base in craniosynostosis.

The configuration of the neurocranium has long been used as a diagnostic tool in assessing infants with abnormal head shape. In the case of craniosynostosis, a characteristic shape is caused by a constraint placed on growth of the neurocranium by prematurely closed sutures and secondary accommodation to that constraint. This investigation is a preliminary test of our hypotheses of growth of the cranial base under these constraints. Three dimensional landmark coordinate data were collected from pre-, peri-, and postoperative CT scans of eleven patients from The Cleft Palate and Craniofacial Deformities Institute, St. Louis, MO. These data were used in two sets of analytical comparisons. Comparisons of preoperative and perioperative morphology were taken to represent preoperative growth, while comparisons of perioperative to postoperative CT scans represent postoperative growth. Finite-element scaling analysis (FESA) and Euclidean distance matrix analysis (EDMA) were used to make these comparisons. Our results show that in cases involving premature closure of the metopic, sagittal, and bilateral coronary sutures, predictions about growth of the cranial base made prior to analysis prove correct. In these forms of craniosynostosis there are characteristic and consistent changes in the cranial base in both pre- and postoperative growth. Preoperative and postoperative growth in patients diagnosed with unicoronal synostosis show a greater degree of individual variability and do not follow a predictable pattern.

Cephalometry↗

PubMed1991

Surgical management of sagittal synostosis. A quantitative evaluation of two techniques.

This article reports a retrospective quantitative (cephalic index) evaluation of the effect that two different operations for treatment of scaphocephaly secondary to sagittal synostosis have on cranial shape. Combining our results with those of others, the trend is clear: if the objective of surgical intervention for isolated nonsyndromal sagittal synostosis is normalization of the calcarial width to length ratio, a more extensive procedure than simple or extended craniectomy is required.

Age Factors↗

PubMed1991

Unicoronal synostosis. A surgical intervention.

Computer-assisted medical imaging technology provides useful tools for the in vivo study of congenital craniofacial deformities. Using these tools, a standardized operation for infants with nonsyndromal unicoronal synostosis has been shown to consistently normalize orbital dimensions and decrease exocranial base angulation. Normalization of endocranial base angulation is less consistent. The plasticity of the infant's cranial base after cranial vault surgery suggests a locus of the primary pathology at a site other than the cranial base.

Craniosynostoses↗

PubMed1991

Cleft palate and velopharyngeal dysfunction.

Surgical and prosthetic interventions are effective means of managing cleft palate and velopharyngeal dysfunction. Most patients are managed surgically because usually there is life-long benefit from that type of intervention and an operation does not require continued cooperation from the patient. In selected cases, prosthetic intervention is preferred. Over the past century, the efficacy of such interventions has increased markedly. Not all of the factors responsible for these improved results are understood. Disagreement among care providers persists regarding the specific criteria for intervention, the use of ancillary tools beyond perceptual speech evaluation for both pre-intervention and postintervention assessments, the technical details of intervention, and the ideal age for intervention. In spite of general success of interventions for cleft palate and velopharyngeal dysfunction, much fertile ground remains to be tilled and harvested by current and future students of the problem.

Child↗

PubMed1991

The importance of positive bacterial cultures of specimens obtained during clean orthopaedic operations.

Microbiological cultures of specimens of tissue and of fluids from the wound in forty patients who had had consecutive clean, elective orthopaedic operations (excluding total joint replacements) and had not received antibiotics preoperatively were analyzed. Of the forty patients, twenty-three (58 per cent) had a positive culture on at least one of the media that were used and seventeen (43 per cent) had negative cultures. Of the forty specimens that were obtained from swabbing of the wound, eight (20 per cent) were positive on culture, compared with twenty (50 per cent) that were obtained from biopsy of tissue. Of these twenty-eight positive cultures, thirteen (46 per cent) were on routine blood-agar plates and fifteen (54 per cent), in broth only. Of the thirty-three bacterial organisms that were identified in the twenty-eight positive cultures of the wound, nineteen (58 per cent) were coagulase-negative Staphylococcus; eight (24 per cent), Propionibacterium acnes; two (6 per cent), Peptostreptococcus; and four (12 per cent), miscellaneous organisms. In all of the positive cultures on the blood-agar plates, except in those showing Propionibacterium acnes, there were five colonies or fewer. One patient had a clinical infection with Staphylococcus aureus that developed later, but the initial cultures of the wound had been positive for Staphylococcus epidermidis only. None of the bacteria that grew on culture were Staphylococcus aureus or the less common pathogenic gram-negative bacteria, such as Escherichia coli, Pseudomonas, or Klebsiella.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

The craniofacial anatomy of Apert syndrome.

The surface dysmorphology of the head in Apert syndrome has been known for a century. Recent advances in computer-assisted medical imaging technology allows in vivo nondestructive "dissection." The authors have used this technology to study the subsurface craniofacial dysmorphology of 14 patients with Apert syndrome ranging in age from infancy to adulthood.

Acrocephalosyndactylia↗

PubMed1991

Surgical correction of the craniofacial dysmorphology of Apert syndrome.

The authors present the objectives, timing, techniques, and results of surgery for the dysmorphology of the cranium, orbits, nose, midface, and mandible of patients with Apert syndrome based on personal experience with 14 patients and comprehensive review of the literature. The status of hypotheses generated in the early phase of craniofacial surgery is discussed. Published schedules for longitudinal treatment are examined and a preferred plan proposed.

Acrocephalosyndactylia↗

PubMed1990

Fracture of the sternum in motor vehicle accidents and its association with mediastinal injury.

Sternal fractures occurred in 78 out of 2097 consecutive victims of road traffic accidents who required to attend hospital; an incidence of 3.7 per cent. They were most common in restrained, front seat vehicle occupants involved in frontal collisions, and their frequency increased with age. There was a positive association with visceral chest injury but the latter was not thought to be the cause of death in any individual. Follow-up of survivors 2-4 years later revealed potential cardiac sequelae in 6 per cent.

Accidents, Traffic↗

PubMed1990

Standardization for the reporting of nasopharyngoscopy and multiview videofluoroscopy: a report from an International Working Group.

A multidisciplinary International Working Group of scientists was assembled to address the question of standardizing reporting techniques for multiview videofluoroscopy and nasopharyngoscopy, the generally accepted standards for direct observation of the velopharyngeal valve. This report is a first attempt to propose standards while seeking feedback from the readership in order to further develop a common methodology.

Cineradiography↗

PubMed1990

Agnathia and associated malformations: a case report.

A case of a rare first branchial arch anomaly with severe hypoplasia of the mandible and fusion between the mandible and adjacent bones is presented. The patient also had intracranial, cardiac, and acral deformities. The craniofacial malformations may reflect incomplete separation of the first branchial arch into its maxillary and mandibular processes. The association between the craniofacial and other corporal anomalies is unknown.

Branchial Region↗

PubMed1990

External fixation for open tibia fractures. A management strategy.

The management of open tibia fractures with the Dynamic Axial Fixator, including the method of application and postoperative care, is described. This fixator is utilized until healing. Weight bearing and axial fracture site movement promote an early callus response. The results obtained in the first 35 cases in which it was used at our institution are presented. Thirty-three of the fractures were successfully treated until healing in the external fixator.

Fracture Fixation↗

PubMed1990

Mechanical analysis of the factors affecting dynamization of the Orthofix Dynamic Axial Fixator.

Loading trials were conducted to identify mechanical factors affecting dynamization of a commercially available external fixator (Orthofix) that is designed to undergo free telescopic motion when axially loaded. Angular variations between the proximal and distal screw clamps and the telescoping fixator body failed to produce fixator binding (failure to dynamize) in any of the loading trials. However, binding was produced by applying external torques in magnitudes that occasionally occur during routine ambulation. The specific torque necessary to induce binding (typically 3-4 Nm) was only a weak function of axial load magnitude, axial loading frequency, or simulated fracture stiffness. Among several geometrical variables of fixator application, only the pre-extension of the telescoping body and circumferential misalignment between proximal and distal pin clusters had an appreciable influence on the threshold binding torque. Axial fixator motions were also monitored in a small adjunct clinical series of 22 dynamized tibial fractures. The fixator dynamized appropriately in 15 cases (68%). Three patients (14%) showed evidence of fixator binding, and another four (18%) had less than predicted slider excursions. The role of several design factors implicated in torque-induced fixator binding is discussed in light of the benchtop and clinical observations.

Biomechanical Phenomena↗

PubMed1990

Craniofacial onlay bone grafting: a prospective evaluation of graft morphology, orientation, and embryonic origin.

A prospective study using 46 young adult New Zealand rabbits was designed to evaluate onlay bone grafts to the craniofacial skeleton with respect to embryonic origin (membranous or endochondral), gross morphology (unicortical or bicortical), and orientation (cortex-to-bed relationship). Quantitative and qualitative data were analyzed and contrasted at both periods of evaluation (1.5 and 3.0 months). The embryonic origin of onlay bone grafts to the rabbit snout is significantly correlated with graft surface area, volume, weight, and recipient bed union for up to 3 months postoperatively. Over this interval, membranous bone (calvaria) grafts either persist in their entirety or increase, whereas endochondral bone (iliac) grafts resorb. Neither the number of cortices (unicortical or bicortical) nor the orientation of unicortical grafts (cortex-to-bed relationship) affected graft fate regardless of embryonic origin. Bone density remained unaltered during both resorption and deposition. Osteogenesis, demonstrated by serial fluorochrome markers, occurs in both membranous and endochondral bone grafts. Histologically, bone grafts of membranous and endochondral origin differ greatly in their cortical to cancellous diploe ratios and architectural configuration. We hypothesize that the differences found are related to the three-dimensional osseous architecture rather than to the embryonic origin of bone per se.

Animals↗