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Biomedical subjects

A E Burns

Publications and source records attributed to A E Burns.

14 recordsLinked to original sources
PubMed2000

Impaired vascular contractility and blood pressure homeostasis in the smooth muscle alpha-actin null mouse.

The smooth muscle (SM) alpha-actin gene activated during the early stages of embryonic cardiovascular development is switched off in late stage heart tissue and replaced by cardiac and skeletal alpha-actins. SM alpha-actin also appears during vascular development, but becomes the single most abundant protein in adult vascular smooth muscle cells. Tissue-specific expression of SM alpha-actin is thought to be required for the principal force-generating capacity of the vascular smooth muscle cell. We wanted to determine whether SM alpha-actin gene expression actually relates to an actin isoform's function. Analysis of SM alpha-actin null mice indicated that SM alpha-actin is not required for the formation of the cardiovascular system. Also, SM alpha-actin null mice appeared to have no difficulty feeding or reproducing. Survival in the absence of SM alpha-actin may result from other actin isoforms partially substituting for this isoform. In fact, skeletal alpha-actin gene, an actin isoform not usually expressed in vascular smooth muscle, was activated in the aortas of these SM alpha-actin null mice. However, even with a modest increase in skeletal alpha-actin activity, highly compromised vascular contractility, tone, and blood flow were detected in SM alpha-actin-defective mice. This study supports the concept that SM alpha-actin has a central role in regulating vascular contractility and blood pressure homeostasis, but is not required for the formation of the cardiovascular system.

Actins↗
PubMed2000

Use of small cannulated screws for fixation in foot surgery.

Use of cannulated bone screws, as compared with use of traditional bone screws, has been reported to decrease surgical time, allow for more precise screw placement, and reduce sources of error. Cannulation of the smaller-size screws that are routinely used in foot surgery has not been available until the last few years. This article reports on the use of the small cannulated screws manufactured by Alphatec Manufacturing, Inc (Palm Desert, California). The screw sizes available in the Mini Lag Screw System are 2.7, 3.5, and 4.0 mm. A long-term clinical and radiographic prospective evaluation of 70 procedures performed on 49 patients was conducted. The follow-up time for all patients was 2 years. None of the 70 implants fractured, and seven procedures (in seven patients) resulted in some type of implant-fixation failure. All of the fixation failures, however, appeared to be related to an untoward event or patient noncompliance. These smaller cannulated screws proved to be a reliable and effective means of fixation in foot surgery.

Bone Screws↗
PubMed1986

Digital arthroplasty.

Correction of digital deformities by an arthroplasty procedure is by far the most commonly used technique. However, the choice of procedure is complicated by contradictory methods described in many texts. The goal of surgery is to maintain as much function as possible, achieve a cosmetic result, and give the best prognosis for avoidance of recurrence.

Arthroplasty↗
PubMed1985

Fractures of the calcaneus.

Fractures of the calcaneus account for approximately 60 per cent of all tarsal injuries and 1 to 2 per cent of all diagnosed fractures. The length of treatment and rehabilitation and disability has a marked effect on the working population. This helps to explain the great disparity in the classification and treatment of calcaneal fractures.

Biomechanical Phenomena↗
PubMed1975

Comprehensive pediatric care: the patient viewpoint.

Two meanings of the term comprehensive care are delineated. The first refers to a wide scope of health services, the second to a humanistic approach to the patient. Findings from a sample of patients from one pediatric practice suggest that the two meanings constitute two independent variables with respect to patient expeciations. Patient responses to questions regarding their expectations of the pediatrician revealed a tendency to hold a traditional disease orientation. Comprehensive care as a broad scope of health services that include mother guidance in child rearing is not a common goal for mothers utilizing the pediatric practice under study. On the other hand, a comprehensive approach by the pediatrician is a standard shared by most respondents in the sample: high priority is accorded the pattern of the personal physician with whom a patient forms a continuous doctor-patient relationship which instills in the patient trust that the physician's recommendations are based on thorough knowledge of the patient as an individual.

Black or African American↗
PubMedDate not supplied

Biofix fixation techniques and results in foot surgery.

Biofix absorbable rods have been used for internal fixation for 10 years, and one of its most utilized applications has been osteotomies of the first metatarsal. This study evaluates 59 procedures on 49 patients completed over a 3-year period, using the 2.0-mm. Biofix rods. The transarticular technique for the fixation of osteotomies in the 1st and 5th metatarsals and the intramedullary technique used for digital fusions are described. All of the patients were followed for a minimum of 3 months, but most for > 1 year, and all of the procedures were evaluated for failure of fixation, osteolytic bone changes, sterile sinus development, and infection. There were no failures of fixation and no infections in this series. Patients (22.4%) developed radiographic osteolytic changes, and 4.1% of the patients developed sterile sinus discharge. However, these had no effect on the procedures' success or outcomes. An introduction to future application of the technology using Biofix screws and plates is made with a pantalar fusion case as an example.

Arthrodesis↗
PubMedDate not supplied

Poly-L-lactic acid rod fixation results in foot surgery.

The purpose of this study was to evaluate the effectiveness and possible complications of polylactic absorbable devices in surgical procedures involving fixation of the foot. This was a prospective study in which biodegradable rods of poly-L-lactide were used in the fixation of 41 metatarsal osteotomies and digital arthrodeses and one midtarsal fusion in 23 patients. The follow-up time ranged from 6 months to 23 months. Ages ranged from 18 to 70 years with a mean age of 42 years. Clinical and radiographic examination was scheduled for each patient postoperatively at 1 week, 3 weeks, 6 weeks, 3 months, 6 months, 1 year, and 2 years. The gender distribution was 18 female and 5 males. Two patients who had three procedures were lost to follow-up. All of the procedures were evaluated for failure of fixation, radiographic osteolysis, foreign-body reaction, sinus formation, and infection. We noted one failure of fixation and two complications unrelated to the type of fixation. There were no foreign-body reactions, sinus formulations, or infections. We conclude that the poly-L-lactic acid rod is a viable method of fixation for these procedures.

Adolescent↗
PubMedDate not supplied

Enchondroma: two case reports.

Although bone tumors of any type are rare in the foot, if they do occur, enchondroma is among the most common. Asymptomatic enchondromas do not warrant treatment, but aggressive treatment is warranted when these tumors are painful. Pain occurs when there is a fracture, compression of soft tissues, or malignant conversion. Methods of treatment include excision, curettage and packing with bone chips, and subtotal or total resection and bone grafting. Two cases of painful enchondroma and how they were treated by different means is presented.

Adult↗
PubMedDate not supplied

Comparison of total hinged and total nonhinged implants for the lesser digits.

The purpose of this paper is to present preliminary findings of an ongoing prospective study of the effectiveness of total digital implants. Forty hinged implants and 22 nonhinged implants have been evaluated to compare the two implants and establish preoperative criteria for their use. Our findings indicate better results for toe purchase and stability with the nonhinged implant and marginally better joint range of movement with the hinged implant. Preoperative dorsal contracture at the metatarsophalangeal joint leads to the most consistent postoperative complications.

Adult↗
PubMedDate not supplied

Revised tarsectomy for correction of relapsed clubfoot.

A modification of the wedge tarsectomy used for correction of components of talipes equinovarus that helps preserve the length of the foot is presented. The procedure is demonstrated with the report of a case that was treated successfully. Correction of deformity in all three body planes in the relation of the forefoot to the rearfoot can be achieved with this combination tarsectomy-bone graft procedure that will simultaneously prevent gross shortening of the foot.

Adult↗