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Biomedical subjects

M A Simon

Publications and source records attributed to M A Simon.

At least 163 records · Page 9Linked to original sources
PubMed1982

Invasion of joints by primary bone sarcomas in adults.

In a retrospective macroscopic and microscopic study of celloidin-embedded macrosections from 45 adults with primary metaphyseal intraosseous sarcomas, we ascertained the incidence, extend, and mode of tumor extension into, across, or around articular cartilage into a joint. Invasion of articular cartilage by tumor occurred in more than one-third of the macrosections examined. In more than one-half of the cases, the sarcoma extended under the capsule insertion to involve the margin of the articular cartilage, thus leaving only a pseudocapsule between tumor and joint. Tumors frequently extended across or around the osseous-tendinous junction of the cruciate ligaments into the knee joint. Our findings have important implications for the surgical management of appendicular metaphyseal intraosseous sarcomas. For primary bone sarcomas, extraarticular resections should be considered seriously when limb salvage is contemplated, especially in the knee region.

Adolescent↗
PubMed1982

The effect of a thigh tourniquet on the incidence of deep venous thrombosis after operations on the fore part of the foot.

We performed a prospective randomized clinical study to determine whether use of a thigh tourniquet influences the incidence of deep venous thrombosis. The lower limbs of patients who were scheduled for elective surgery on the fore part of the foot were randomized and assigned to one of three treatment categories: Group I, no tourniquet; Group II, exsanguination by an Esmarch bandage before tourniquet application; and Group III, exsanguination by elevation of the extremity prior to application of a tourniquet. The 117 limbs of seventy-one patients included in this study were evaluated preoperatively and twenty-four and seventy-two hours postoperatively with 125I-labeled fibrinogen, and preoperatively and seventy-two hours postoperatively with Doppler ultrasound studies and phleborheography. The findings in all of the Doppler ultrasound studies and all of the phleborheograms were normal. Two of the 125I-fibrinogen studies were positive, but subsequent contrast venography revealed that these were false-positive findings. We therefore concluded that the use of a thigh tourniquet does not increase the risk of deep venous thrombosis in patients who have had an operation on the fore part of the foot.

Adult↗
PubMed1982

Skeletal metastases of unknown origin. Diagnostic strategy for orthopedic surgeons.

Twelve patients with skeletal metastases from occult primary carcinomas were evaluated in an effort to develop an efficient routine for detecting the primary tumor in such cases. In all of the cases the initial medical histories, physical examinations, and laboratory tests failed to detect the site of the primary carcinomas. The primary sites in five patients were identified by simple imaging studies; three patients had hypernephromas and two had lung carcinomas. In spite of subsequent extensive diagnostic testing, the primary site was identified antemortem in only one additional patient. A routine strategy has been designed for locating skeletal metastases and detecting the primary site of a carcinoma. If this routine does not identify the patient's primary site, no further diagnostic tests need be performed.

Adult↗
PubMed1981

The 5' termini of RNAs encoded by the transposable element copia.

The 5' termini of copia-specific RNAs in Drosophila melanogaster tissue culture cells were determined by S1 nuclease mapping and cap analysis. Both major copia RNAs share an identical set of heterogeneous 5' ends. Three major cap 1 structures M7GpppCmpUp, M7GpppCmpCp and M7GpppGmpUp together with several other minor caps were found. Almost all the 5' termini, as judged by S-1 nuclease mapping, were located either in a pyrimidine-rich part of the terminal direct repeat or apparently outside of the copia element, suggesting that a proportion of copia transcripts derive from promoters external to the genetic element.

Animals↗
PubMed1981

Histiocytic lymphoma (reticulum-cell sarcoma) of bone. Current strategy for orthopaedic surgeons.

We retrospectively reviewed the cases of eight patients with histiocytic lymphoma (reticulum-cell sarcoma) appearing as a primary bone lesion. Histological findings were classified according to the criteria of Rappaport. Lesions were staged as suggested by the Ann Arbor Conference. After thorough staging, four of the eight patients were shown to have more extensive disease than was initially thought, which altered the therapeutic approach used. Thorough staging is necessary for improved survival of patients with histiocytic lymphoma of bone. We suggest a diagnostic strategy for patients with histiocytic lymphoma presenting in bone that leads to appropriate therapy.

Adult↗
PubMed1980

Insertion of the Drosophila transposable element copia generates a 5 base pair duplication.

To examine the details of insertion for the D. malanogaster transposable element copia, we have isolated three independent pairs of genomic fragments which correspond to occupied and unoccupied target sites for insertion. Restriction endonuclease analysis suggests that sites with and without an element differ by a simple 5000 bp insertion. Direct DNA sequence analysis demonstrates that a 5 bp sequence, present once in the target DNA at the site of insertion, is found on both sides of the element after insertion. The 5 bp sequences which are duplicated are different in each case. Moreover, there does not appear to be any sequence homology among these three independent insertion sites

Animals↗
PubMed1980

Scintigraphic evaluation of primary bone tumors. Comparison of technetium-99m phosphonate and gallium citrate imaging.

A prospective investigation of two different radionuclide imaging techniques for the skeleton--technetium-99m phosphonate and gallium-67 citrate--was carried out prior to biopsy in fifty-five patients with primary bone tumors of the extremities and limb girdles. The study showed that the technetium-99m phosphonate scans were not useful in separating benign from malignant lesions or in defining reliably the local extent of malignant tumors. Gallium scans were more accurate in delineating the local extent of malignant tumors and may provide better indentification of benign tumors.

Bone Neoplasms↗
PubMed1980

Epiphyseal extension of metaphyseal osteosarcoma in skeletally immature individuals.

In a restrospective macroscopic and microscopic study of twenty-six macrosections of skeletally immature individuals with metaphyseal osteosarcoma, we determined the incidence, extent, and mode of tumor extension into the epiphysis. The physis appeared to have a tendency to act as a barrier to tumor spread, but did not restrain the tumor tissue in most cases. Epiphyseal extension of the tumor tissue was massive in more than half of the cases, with tumor tissue abutting against the articular cartilage, and in one instance perforating it. Some tumors had a sizable extra-osseous component that extended around the physis beneath the perichondral ring and capsular structures into the ossific nucleus. These findings have important implications when limited surgery is performed for appendicular osteosarcoma.

Adolescent↗
PubMed1979

The effect of biopsy on survival of patients with osteosarcoma.

A retrospective study of patients with osteosarcoma was undertaken to determine whether there was a relationship between biopsy and survival. Fifty-seven patients treated at the Karolinska Hospital, Stockholm, between 1938 and 1959 were included in this study, all of whom were less than thirty years old, had a metaphysial osteosarcoma in a long bone but had no pulmonary metastases at the time of diagnosis; all were treated by amputation. No clinical variants of osteosarcoma were included. Twenty-four of the fifty-seven patients had an amputation without a prior biopsy; the others had biopsies before amputation. These two groups were fairly closely matched in age, sex, site and size of tumour, and in the level of amputation; some patients in each group received radiation before operation. Evaluation of these two groups of patients revealed that the performance of a biopsy, with or without a delay of not more than thirty days between the biopsy and the definitive operation, had no adverse effect on survival.

Adolescent↗
PubMed1978

Scintigraphic evaluation of sarcomata in children and adults by Ga67 citrate.

Gallium-67 scans were performed on 32 patients with adult and childhood sarcomata as part of clinical staging studies. Gallium-67 scans proved to be highly accurate in assessing sites of disease in patients with malignant schwannoma, Ewing's sarcoma, and rhabdomyosarcoma. Gallium-67 scans were inaccurate in determining sites of disease in patients with other types of sarcomata. It is concluded that Gallium-67 scanning is a useful adjunct to clinical staging in selected patients with sarcomata.

Adolescent↗
PubMed1978

Childhood leukemia presenting as a diaphyseal radiolucency.

A 41-month-old black child with a symtomatic diaphyseal destructive lesion of the femur, and a corresponding area of increased uptake on a technetium99m bone scan, had an upper respiratory tract infection. An open biopsy was performed because of an initial clinical diagnosis of osteomyelitis, histiocytosis X or a round cell sarcoma. The biopsy showed numerous blast cells compatible with acute lymphocytic leukemia. Acute leukemia should be included in the differential diagnosis of symptomatic diaphyseal destructive lesions in children. A peripheral blood smear should be carefully interpreted prior to any other invasive diagnostic tests.

Child, Preschool↗