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Biomedical subjects

R L Randall

Publications and source records attributed to R L Randall.

13 recordsLinked to original sources
PubMed2006

Rhabdomyosarcomas utilize developmental, myogenic growth factors for disease advantage: a report from the Children's Oncology Group.

BACKGROUND: Unresectable or metastatic disease represents the greatest obstacle to cure for children with rhabdomyosarcoma. In this study we sought to identify gene expression signatures of advanced stage and progressive disease. PROCEDURE: Using oligonucleotide gene expression analysis for a focused set of 60 genes, we analyzed the myogenic expression profiles of 89 rhabdomyosarcomas from the Intergroup Rhabdomyosarcoma Study-IV. RESULTS: While the expression profile of rhabdomyosarcomas closely paralleled gene expression profiles of normal embryonic myogenic progenitors, growth factors were most closely associated with disease progression. Specifically, we identified platelet-derived growth factor (PDGF) receptors and insulin-like growth factor as strongly correlated with decreased failure-free survival. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) of an independent data set suggested that autocrine growth signaling, if present, is not regulated in a simple manner at the transcriptional level. CONCLUSIONS: Increased transcriptional levels of PDGF receptors and insulin-like growth factor are associated with decreased survival in rhabdomyosarcomas. Dual blockade of these growth-factor-signaling pathways may be a valuable strategy in preclinical therapeutic studies.

Adolescent↗
PubMed2006

Heterogeneous expression of melanoma antigen (hMAGE) mRNA in mesenchymal neoplasia.

Recommendations have been advanced recently for the use of cancer/testis (CT) immunotherapy against sarcomas. CT antigens are encoded by cancer-germline genes (e.g., hMAGE family) that are expressed in tumors and male germline cells but typically not in normal tissues. At present, little information is available regarding CT expression in mesenchymal neoplasms, and it remains uncertain whether CT immunotherapy will serve as a viable alternative or adjunct to current sarcoma therapies involving resection, followed by adjuvant radiotherapy and/or chemotherapy. In this study, hMAGEA2, hMAGEA3, hMAGEA4, and hMAGEC1 mRNA content in 21 benign mesenchymal tumors (representing seven histotypes) and 28 primary sarcomas (10 histotypes) was inventoried using real-time-PCR and then compared against hMAGE mRNA expression in non-sarcomatous malignancies, three cell lines, and muscle. hMAGEA2, hMAGEA3, and hMAGEC1 transcripts were infrequent in mesenchymal tissues in general, whereas hMAGEA4 mRNA was present in 84% of all mesenchymal tumors, 100% of non-sarcomatous tumors, all three cell lines, and in four of five muscle samples. Although hMAGEA4 mRNA was detected in four of five muscle preparations, there was no indication that the mRNA was translated into protein. The presence of hMAGEA4 mRNA in muscle, plus the inconsistent and infrequent occurrence of hMAGEA2, hMAGEA3, and hMAGEC1 mRNA within and among mesenchymal tumor histotypes, makes these four hMAGE antigens unlikely candidates for sarcoma-specific immunotherapy.

Antigens, Neoplasm↗
PubMed2004

Errors in diagnosis and margin determination of soft-tissue sarcomas initially treated at non-tertiary centers.

One hundred four patients with soft-tissue sarcoma referred to our institution who were initially managed at an outside medical center were retrospectively reviewed. The accuracy of histologic diagnosis and adequacy of tumor resection performed at these centers was evaluated. Review of the original pathologic specimens was performed. Thirty-seven percent of the histologic diagnoses were changed, and 82% of cases with excisional or wide resections had positive margins. The incidence of errors in diagnosis and inadequate tumor resection suggest that biopsy and histologic analysis of sarcomas should be performed by physicians experienced in their management.

Adolescent↗
PubMed2002

Durability and strength of Steinmann pin augmentation in cemented tibial defects.

It has been argued that Steinmann pin augmentation does not improve the biomechanics of polymethylmethacrylate reconstruction for massive defects of bone. The current authors investigated whether pin augmentation of polymethylmethacrylate in the reconstruction of noncontained defects of bone improved the biomechanical properties of the reconstruction as compared with polymethylmethacrylate alone when minimal or large bone porosity is present. Large noncontained defects were created in 10 pairs of human tibias. In Group 1, five left tibias had reconstruction with polymethylmethacrylate augmented with three, 5-mm diameter by 10-mm deep holes into lateral condyle cancellous bone. Right tibias had identical reconstruction with three, 3/16-inch threaded pins placed into the medullary canal. In Group 2, three, 10-mm diameter by 10-mm deep holes were created in both pairs. The left tibia had polymethylmethacrylate reconstruction and the right tibia had polymethylmethacrylate and pin augmentation. Specimens were subjected to 2000 compressive cycles then loaded to failure. In Group 1, cycles and load to failure were significantly lower in reconstructions without pins compared with reconstructions with pins. No significant difference was observed between reconstruction techniques in Group 2. In reconstructions without pins, large diameter holes had significantly better cyclical durability. Pins improved survival compared with no pins.

Adult↗
PubMed2000

Aggressive aneurysmal bone cyst of the proximal humerus. A case report.

The case of an 11-year-old girl with a rapidly expanding, massive lesion in the right proximal humerus is reported. After biopsy, surgical treatment of the aneurysmal bone cyst consisted of aggressive intralesional resection with autogenous tibial strut grafting for reconstruction. After followup of 17 years with no recurrence of disease, there is excellent graft incorporation and remodeling and excellent function of the shoulder.

Biopsy↗
PubMed1999

Comparison of bone-patellar tendon-bone interference screw fixation and hamstring transfemoral screw fixation in anterior cruciate ligament reconstruction.

While bone-patellar tendon-bone (BPTB) interference screw anterior cruciate ligament (ACL) reconstruction is a biomechanically sound construct, alternative techniques have been developed secondary to potential donor site morbidity. This study evaluates a system designed to address this problem that involves a transfemoral screw fixation device and stapling of hamstring tendons. Seven pairs of cadaveric knees underwent ACL reconstruction using either BPTB interference screw technique or semitendinosus gracilis (STG) transfemoral screw fixation and stapling. Tensile testing was performed. There was no significant difference between the two fixation types with regard to stiffness, maximum load to failure, elongation, energy to failure and yield load, displacement, and energy.

Aged↗
PubMed1998

Ewing's sarcoma masquerading as osteomyelitis.

Ewing's sarcoma in the infant and young child is rare, highly malignant, and can be difficult to identify. An erroneous diagnosis of osteomyelitis may be considered first because the presentation may be similar to that of Ewing's sarcoma, and routine laboratory evaluation may not distinguish between these entities. Two such cases are presented, one involving the tibia in a 16-month-old child and another a finger phalanx in a 7-month-old child. In both cases the correct diagnosis of Ewing's sarcoma was delayed because of initial misdiagnosis of osteomyelitis. This diagnostic dilemma is summarized, and the literature reviewed. Special attention is given to recent advances in histochemistry and cytogenetics that assist in tumor identification. The conclusion highlights areas of remaining controversies for which additional study may facilitate distinction between osteomyelitis and Ewing's sarcoma.

Bone Neoplasms↗
PubMed1997

An unusual midfoot dislocation: a case report.

An unusual case of dislocation of the midfoot through the calcaneocuboid and naviculocuneiform joints is presented. The prognosis is excellent for most midfoot dislocations, as long as they are recognized and treated early.

Adult↗
PubMed1996

Orthopedic soft-tissue tumors. Concepts for the primary care physician.

Mesenchymal neoplasia includes an extensive variety of tumors. It is important that the primary care physician understand the different qualities of benign and malignant processes in incidence, pathogenesis, history, physical findings, and diagnostic work-up and, as a result, be able to make the appropriate orthopedic consultation when necessary. It also is important that they understand basic concepts of definitive treatment so that they may educate their patients. Table 2 lists some of the more common benign and malignant soft-tissue tumors. It is by no means an attempt to be inclusive, but rather to serve as an introduction to a vast group of neoplasms.

Biopsy↗
PubMed1993

Pilon fractures of the distal tibia.

Pilon fractures are relatively rare fractures of the distal metaphysis of the tibia resulting from axial and/or rotational forces. They involve varying degrees of metaphyseal disruption, articular damage, and malleolar displacement. When severe, these injuries represent a tremendous challenge to the orthopaedic trauma surgeon. Traditional treatment of high-grade pilon fractures by closed means has led to unsatisfactory results. Open reduction and internal fixation in accordance with AO/ASIF principles has greatly improved the outcome in these often disabling fractures. Surgical technique involves anatomic restoration of fibular length, reconstruction of the plafond, bond grafting of the metaphyseal defect, and buttress plating of the medial tibia. Thorough preoperative planning and meticulous surgical technique produce predictably good results in the majority of cases.

Ankle Injuries↗
PubMed1992

Can MR imaging effectively replace diagnostic arthroscopy?

A study was performed to determine whether magnetic resonance (MR) imaging is cost-effective and reduces the need for diagnostic arthroscopy of the knee. During a 9-month period, 103 consecutive patients with knee injury that justified diagnostic arthroscopy underwent MR imaging. The MR images were interpreted by means of consensus of three radiologists and reviewed with the referring sports medicine orthopedists. After the examination, 44 patients (42.7%) underwent immediate arthroscopy. The 59 other patients (57.3%) did not undergo arthroscopy; follow-up was performed in 55 of these 59 patients (93%) at a mean of 22 months. The outcome was successful in 49 of 55 patients (89%); 40 patients had normal function and no limitation in activity, six patients with chronic injury of the anterior cruciate ligament underwent reconstruction, and three patients underwent arthroscopy with negative findings. Without the use of MR imaging, all patients in this study would have undergone diagnostic arthroscopy. Because of the diagnoses based on MR images, 53 patients (51.4%) avoided a potentially unnecessary diagnostic arthroscopy, and, as a result, the net savings was $103,700 in the 103 patients.

Adolescent↗
PubMed1982

Stages in the role cycle of pastoral counseling.

Contends that there is a role of pastoral counseling which moves through a cycle with discernable stages. These role cycle stages are independent of any particular life stage the individual pastoral counselor may be passing through and may be traversed at any age of adulthood. The stages identified are: pastoral counselor role acquisition; pastoral counseling role performance; pastoral counselor's role assessment; and pastoral counseling role restructuring or rejection. Concludes with a brief statement of implications of a role stage theory.

Humans↗