Biomedical subjects

B A Alman

Publications and source records attributed to B A Alman.

28 records · Page 2Linked to original sources

PubMed1995

The expression of platelet-derived growth-factor gene in Dupuytren contracture.

Dupuytren contracture is a disease of the palmar fascia characterized by nodular fibroblastic proliferation; its etiology and pathogenesis are poorly understood. Growth factors are polypeptides that regulate cell growth and differentiation and extracellular matrix production. Platelet-derived growth factor is known to cause fibroblastic proliferation, and it may be involved in the pathogenesis of Dupuytren contracture. The purpose of this study was to determine if the gene for the B chain of platelet-derived growth factor is expressed in Dupuytren contracture. Tissue from patients who had Dupuytren disease was examined immunohistochemically with the 5B5 antibody, which is a marker for fibroblasts. Polymerase chain reaction, gel electrophoresis, Southern blotting, and in situ hybridization were also used to study gene expression in the tissue as well as in normal fascia, A172 cells, and MRC5 cells. Total cellular RNA was extracted from tissue and cells. Polymerase chain reaction was done with oligonucleotide primers complementary to a portion of the platelet-derived growth-factor-B and platelet-derived growth-factor-receptor genes. The platelet-derived growth-factor-B gene was expressed in all six specimens from the patients who had Dupuytren contracture as well as in the A172 cells, but not in the normal fascia lata or the MRC5 cells. These results were confirmed with Southern blotting of the products of the reaction with a platelet-derived growth-factor-B probe. The gene for the platelet-derived growth-factor receptor was expressed by all tissues and cells studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Blotting, Southern↗

PubMed1995

Massive allografts in the treatment of osteosarcoma and Ewing sarcoma in children and adolescents.

A retrospective review was performed of the results of all allograft reconstructions that had been done after the resection of an osteosarcoma or an Ewing sarcoma in a skeletally immature patient between 1982 and 1989 at The Hospital for Sick Children in Toronto. There were twenty-six patients. Six reconstructions were intercalary, sixteen were resection arthrodeses, three followed resection of a bone segment including the epiphysis (osteoarticular reconstruction), and one was a replacement of the entire humerus. Resection arthrodesis about the knee was performed with a smooth intramedullary rod and with one growth plate left intact. Six procedures were performed in the upper extremity. Excluding the patients who died, the average duration of follow-up was five years and three months. Twenty-one of the twenty-six patients had reached skeletal maturity at the time of follow-up. Eighteen (69 per cent) of the patients had a good or excellent result, four (15 per cent) had a fair result, and four had a failure. Twenty patients (77 per cent) had at least one complication (other than a limb-length discrepancy), and fourteen (54 per cent) sustained at least one fracture of the allograft. Fifteen patients who had had a reconstruction in the lower extremity had survived with survival of the allograft at the time of the latest follow-up. A limb-length discrepancy of at least two centimeters developed in nine of the fifteen patients. Five were managed with a contralateral epiphyseodesis, and one of them had an unsuccessful attempt at limb-lengthening as well. The patients who had a limb-length discrepancy of more than three centimeters at the time of follow-up had been significantly younger (p < 0.05) at the time of the reconstruction than those who had a smaller discrepancy. Three allografts (12 per cent), two of which were implanted early in the series, became infected. Soft-tissue coverage is of paramount importance for the prevention of infection, and we now routinely perform primary muscle (gastrocnemius or latissimus dorsi) transfers when dealing with an inadequate muscle envelope. Twelve patients were followed for more than four years (average, six years and seven months); they had no complications other than increased limb-length discrepancy and one subluxation of the shoulder after the first four years following the reconstruction. Although the rate of complications is higher than in adults, allograft reconstruction remains a useful option for the management of skeletally immature individuals.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

PubMed1995

Proximal femoral focal deficiency: results of rotationplasty and Syme amputation.

We reviewed the results of treatment of sixteen patients who had had an isolated unilateral proximal femoral focal deficiency; nine were managed with a rotationplasty and seven, with a Syme amputation combined with an arthrodesis of the knee. We evaluated the perceived physical appearance, gross motor function, and metabolic energy expended in walking. The mean duration of follow-up was 9.9 years (range, four to fourteen years). The mean age of the patients at the time of the study was 13.9 years (range, eight to 18.4 years) in the rotationplasty group and 14.8 years (range, 9.5 to 19.9 years) in the Syme-amputation group. There were three female patients in each group. Roentgenograms showed that the femoral head was in the acetabulum (Aitken class A or B) in four of the seven patients in the Syme-amputation group and in five of the nine patients in the rotationplasty group; the remaining patients did not have this finding (Aitken class C or D). There was no difference in gross motor function or perceived physical appearance between the groups. Rotationplasty was associated with a more energy-efficient gait (mean, 0.153 milliliter of oxygen per kilogram-meter [range, 0.128 to 0.173 milliliter of oxygen per kilogram-meter] than was Syme amputation (mean, 0.169 milliliter of oxygen per kilogram-meter [range, 0.151 to 0.182 milliliter of oxygen per kilogram-meter]). Both types of treatment resulted in a net oxygen utilization per distance (efficiency) that was less than the values reported after amputations performed for non-congenital disorders.

Activities of Daily Living↗

PubMed1994

Giant marginal ulcer.

Marginal ulcer is a well-known complication of gastroenterostomy. It occurs in 3% of patients post-Billroth II subtotal gastrectomy; it occurs in less than 1% if truncal vagotomy is included but in up to 30% of patients with gastroenterostomy without vagotomy. These ulcers occur at the anastomosis, but always on the jejunal side, and are known to develop complications of their own--e.g., intractable pain; hemorrhage, obstruction, perforation, and fistula formation. Prior to the advent of upper-GI endoscopy the main method of diagnosis was by history and upper GI series but the accuracy of the upper-Gi series was about 50% or less. Now that upper-GI endoscopy is available, the accuracy of diagnosis is 95% or better. Since truncal vagotomy has been widely adopted as an integral part of gastric surgery--e.g., antrectomy, hemigastrectomy, subtotal gastrectomy, and gastroenterostomy--the incidence of marginal ulcer has declined. The use of cimetidine, ranitidine, famotidine, omeprazole, sucralfate, and antacids has improved the medical management of duodenal ulcer to such a degree that in recent years there is much less need for surgical intervention and thus the incidence of marginal ulcer has declined even more. In addition, the H-2 blockers and omeprazole can be used in patients with marginal ulcer and achieve healing; therefore complications that so frequently required surgical intervention are much less frequent.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗

PubMed1993

Digital nerves of the foot: anatomic variations and implications regarding the pathogenesis of interdigital neuroma.

Seventy-one cadaveric feet were dissected, with attention to communicating branches of the digital nerves, the diameters of the digital nerves, the distance between the metatarsal heads, and the presence or absence of interdigital neuromas. A communicating branch was absent in 52 feet (73.2%) and present in 19 specimens (26.8%). The communication was from the fourth to the third web space common digital nerve (i.e., from the lateral to the medial plantar nerve) in 11 specimens. A reverse communication, from the third to the fourth web space common digital nerve (i.e., from the medial to the lateral plantar nerve), was present in eight specimens. Neuromas were identified in the second web space in 26 specimens and in the third web space in 32 feet. The common digital nerve to the third web space was not thicker in feet with a contribution from the fourth to the third web space nerve. Additionally, the incidence of third web space neuroma in feet with this type of communication was not significantly greater than in those feet without an internervous communication. However, the intermetatarsal head distances and the ratios of the intermetatarsal head distance to the digital nerve diameter in web spaces 2 and 3 were significantly smaller in comparison to spaces 1 and 4 (P < .05). The morphometric data lend support to theories that explain the propensity for neuroma formation in both the second and third web spaces on a mechanical basis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1992

Aggressive fibromatosis.

Ten patients with aggressive fibromatosis of the extremities were prospectively followed for 2-6 years. Results of treatment methods were compared. Five patients underwent three-dimensional imaging with and without intravenous contrast, and the images were compared with the anatomic extent of the resected lesion. Pathologic specimens and control tissue were tested for the presence of estrogen and progesterone receptors and for expression of the c-sis oncogene and platelet-derived growth factor (PDGF), potent mitogens for fibrocytes. Wider surgical resection resulted in a lower recurrence rate, but current chemotherapeutic agents were not effective in eradicating the tumors. Intravenous contrast enhanced the lesions. Two thirds of the tumors tested had estrogen or progesterone receptors. All tumors tested had inappropriate expression of c-sis and PDGF. This inappropriate expression may be responsible for the underlying pathobiology and deregulation of control of growth in aggressive fibromatosis.

Adult↗

PubMedDate not supplied

Solitary osteochondroma of the clavicle.

There are no clinicopathologic reports of solitary osteochondroma of the clavicle other than listings in tumor registries. Two boys had solitary asymptomatic osteochondroma, in one at the medial and in the other at the lateral aspect of the clavicle. One underwent excision to correct cosmetic deformity. Several histologic and experimental studies have shown that osteochondromas originate from cells of the growth plate. During development of the clavicle, cartilage appears on both the medial and lateral aspects. Histologic studies have suggested that this cartilage is similar to a physeal growth plate. Experimental studies, however, have shown it to be a randomly organized secondary cartilage that develops in membranous bones once ossification has begun. The occurrence of an osteochondroma at the ends of the clavicle lends support to the theory that the cartilage at the ends of the developing clavicle functions as a growth plate.

Bone Neoplasms↗

PubMedDate not supplied

Potential treatment for clubfeet based on growth factor blockade.

Select soft tissues in clubfeet are contracted, resulting in stiffness. These contracted tissues share ultrastructural characteristics with palmar fibromatosis (Dupuytren contracture), in which the growth factors transforming growth factor-beta (TGF-beta) and platelet-derived growth factor (PDGF) are expressed and play a role in regulating cell behavior. More contracted tissue (medial side of the foot) and less contracted tissue (lateral side of the foot) from 20 clubfeet were studied using reverse transcription-polymerase chain reaction and western analysis for expression of TGF-beta and PDGF (along with collagen type I and type III). Cell cultures were established from the more contracted tissues to determine the effect of blockade of these factors with neutralizing antibodies on proliferation, chemotaxis, and collagen expression. Both growth factors were expressed at higher levels by the contracted tissues, and blockade led to decreased collagen expression, proliferation, and chemotaxis. Growth factor blockade has the potential to change the behavior of these cells in a way that would lessen the severity of the contractures, perhaps improving the outcome of clubfoot treatment.

Cells, Cultured↗

PubMedDate not supplied

Subtalar arthrodesis for stabilization of valgus hindfoot in patients with cerebral palsy.

All patients with spastic cerebral palsy who underwent correction of valgus hindfoot by Grice extraarticular subtalar arthrodesis between 1971 and 1986 performed by two surgeons using an identical technique were reviewed. Twenty-nine patients (53 feet) were followed at an average of 8.9 years after operation. Traditional radiographic criteria for measurement of hindfoot alignment in skeletally mature individuals have poor reliability. Talar head uncovering is a useful and reproducible method for evaluation of hindfoot valgus in these patients. Five patients had progressive hindfoot or ankle deformity at latest follow-up. All five of these patients were spastic quadriplegics. There was no recurrence in the 17 patients who were less severely involved than the quadriplegic patients.

Arthrodesis↗

PubMedDate not supplied

Femur fractures in institutionalized patients after hip spica immobilization.

The charts of 77 severely handicapped institutionalized children and young adults were retrospectively reviewed to assess the incidence of femur fractures. No fractures occurred in ambulatory patients. Four of 37 nonambulatory patients who did not have hip surgery (10.9%) had sustained a fracture at some time during their life. Six of 21 (29%) nonambulatory patients who were operated on for subluxed or dislocated hips sustained a femur fracture within 3 months after discontinuation of their spica casts. This risk factor should be taken into account when one considers operation in severely affected nonambulant spastic quadriplegic patients.

Adolescent↗